AnaCi za istrsiçe in mediterans((e študije Atinad di Studi istriani e mediterranei Annais for lstran and Mediterranean Studies 23/'01 UDK 5 Annales, Ser. hist. nat., 11, 2001, 1 (23), pp. 1 -146, Koper 2001 ISSN 1408-533X AnnaleS Anaii za istrsfig in mediterans((e. študije JAnnaCi di Studi istriani e mediterranei SinnaCs for lstran and Mediterranean Studies 23/'01 UDK 5 Annales, Ser. hist, nat., 11, 2001, 1 (23), pp. 1 -146, Koper 2001 ISSN 1408-533X . 1 i -if A^^M) iU b 1 le Banka Koper ISSN 1408-533X 9771408533025 UDK 5 ISSN 1408-533X AnnaleS Anali za istrske in mediteranske študije Annaii di Studi istriani e mediterranei Annals for Istran and Mediterranean Studies 23/f2001 series historia naturalis, 11, 2001,1 KOPER 2001 ANNALES • Ser. hist, nat, • 11 • 2001 • 1 (23) Anali zz istrske in mediteranske študije - Annali di Studi istriani e mediterranei - Annals for lstran and Mediterranean Studies Ann, Ser. hist, nat., 11, 2001,1 (23) ISSN 1408-533X UDK 5 Letnik 11, leto 2001, številka 1 (23) UREDNIŠKI ODBOR/ COMITATO DI REDAZIONE/ BOARD OF EDITORS: Glavni u re d n i k/Reda ttore Capo/Managing Editor: Odgovorni urednik naravoslovja/ Reda ttore responsabile per le scienze naturali/ Natural Science Editor: Urednica/Redattrice/Editor: Lektorji/Supervisions/Language editors: Preva\a\c\/Traduttori/Translators: Oblikovalec/Progetto grafico/Graphic design: Prei om/Composizion e/ Typese tting: dr. 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ANNALES • Ser. hist. nat. • 1Í • 2001 ■ 1 (23) Anali za istrske in mediteranske študije - Anrtali di Studi istriani e med i ter rane i - Annals for Istran and Mediterranean Studies UDK 5 Letnik 11, Koper 2001, Številka (t) 23 iSSN 1408-533X VSEBINA / ÍNDICE GENERALE/ CONTENTS IHTIOLOGIJA irriOLOGÍA ICHTHYOLOGY loan Barrull & Isabel Mate Presence of the Great White Shark, Carcharodon carchadas (Linnaeus, 1758) in the Catalonian Sea (NW Mediterranean): Review and discussion of records, and notes about its ecology.................. 3 Pojavljanje belega morskega volka Carcharodon carcharías (Linnaeus, 1758) v Katalonskem morju (SZ Sredozemlje): pregled zapisov in beležke o njegovi ekologiji Antonio Ce iona, Nicola Donato & Aiessandro De Maddaiena In relation to the captures of a great white shark, Carcharodon catcharlas (Linnaeus, 1758), and a shortfin mako, Isurus oxyrhtnchus Rafinesque, 1809, in the Messina Strait .............................................. 13 V zvezi z ujetjem belega morskega volka Carcharodon carcharías (Linnaeus, 1758) in atlantskega maka Isurus oxyrhinchus Rafinesque, 1809 v Messinskem prelivu Aiessandro De Maddaiena & Luigi Piscitelii Morphometries of neonate velvet belly, Etmopterus spinax (Linnaeus, 1758) ...................... 17 Morfometrija novoskotenih črnih trnežev Etmopterus spinax (Linnaeus, 1758) Joan Barrull & Isabel Mate First confirmed record of angular roughshark Oxynotus centrina (Linnaeus, 1758) predation on shark egg case of small-spotted catshark Scyliorhinus canícula (Linnaeus, 1758) in Mediterranean waters ............. 23 Prvi potrjeni primer oplenjenega jajčnega ovoja morske mačke Scyliorhinus canícula (Linnaeus, 1758) i/ trebuhu morskega prašiča Oxynotus centrina (Linnaeus, 1758) v Sredozemskem morju Suzana Šumer, Srečko Leiner & Meta Povž Marble trout (Salmo marmoratus) and bullhead (Cottus gob i o) in two Slovene rivers (Adriatic Sea Basin) ............................................... 29 Soška postrv (Saimo marmoratus) in glavač (Cottus gobio) v dveh slovenskih rekah severnojadranskega po vod j a Jakov Dulčič & Armin Pallaoro Some new data on Xyrichthys novacula (Linnaeus, 1758) and Sparisoma (Eusc.arus) cretense (Linnaeus, 1758) from the Eastern Adriatic..................................................... 35 Nekaj novih podatkov o vrstah Xyrichthys novacula (Linnaeus, 1758) in Sparisoma (Euscarus) cretense (Linnaeus, 1758) iz vzhodnega Jadrana EKOLOGIJA MORJA ECOLOGIA MARINA MARINE ECOLOGY Alenka Malej, Boris Petelin & Branko Čermelj Quantification of mucilage-associated suspended matter in the Gulf of Trieste (Adriatic Sea)............. 43 Ovrednotenje količine sluzi v Tržaškem zalivu (jadransko morje) Valentina Turk, Patricija Mozetič & Alenka Malej Seasonal variability in phytoplankton and bacterioplankton distribution in the semi-enclosed temperate Gulf (Gulf of Trieste, Adriatic Sea) ............................................. 53 Sezonska razporeditev fitoplanktona in bakterioplanktona v polzaprtem zalivu (Tržaški zaliv, Jadransko morje) Nives Kovač, Borut Vrišer & Branko Čermelj Impacts of net cage fish farm on sedimentary biogeochemical and meiofaunal properties of the Gulf of Trieste ............................................. 65 Vplivi gojenja rib na meiofavno ter biogeokemične lastnosti sedimenta Tržaškega zaliva ANNALES Ser. hist. nat. • 11 • 2001 1 (23) Anali za istrske in mediteranske študije - Annali cti Studi istriani e mediterranei - Annals for Istran and Mediterranean Studies Borut Vrišer Meiofavna izolske luke pred graditvijo marine in po njej: ponovljena raziskava - preliminarni rezultati ............................................. 75 Meiofauna of the Izola harbour area 8 years after the new marina was completed: A repeated investigation - preliminary results VARSTVO NARAVE TUTELA DELL'AMBIENTE NA TURE CONSERVATION Cvido Piasevoli & Vlatka Ščetarič Eleonora's Falcon (Falco eleonorae, Gene 1839) in Croatia: Range, threats and the proposal of action and management plan ............................ 81 Sredozemski sokol (Falco eleonorae, Gene 1839) na Hrvaškem: njegova razširjenost; ogroženost in predlog za akcijski načrt in načrt upravljanja Andrej Sovine Zavarovana območja kot orodje za ohranjanje biod i verz itete v Sredozemlju ................................. 87 Protected areas as an instrument for the conservation of biodiversity in the Mediterranean Gregor Kovačič Pokrajinska ogroženost in ukrepi za zaščito kraškega izvira Bistrica .......................................... 93 The environmental vulnerability of the Bistrica karst spring and suggested measures for its protection MISCELLANEA Irena Rot-Nikčevič, Vesna Sidorovska, Georg Džukič & Miloš L. Kalezič Sexual size dimorphism and life history traits of two European spadefoot toads (Pelobates fuscus and P. syriacus) in allopatry and sympatry......................................................... 107 Velikostne razlike med spoloma in življenjske značilnosti dveh evropskih česnovk {Pelobates fuscus in P. syriacus) v alopatriji in simpatriji Tone Novak & Tatjana Čelik Scientific life and work of Narcis Mršič (1951-1997) ..................................... 121 Znanstveno življenje in delo Narcisa Mršiča (1951-1997) DELO NAŠIH DRUŠTEV ATT1V1TÀ DEI NOSTR1ISTITUTI E DELLE NOSTRE SOCIETÀ ACTIVITIES BY OUR INSTITUTIONS AND ASSOCIATIONS Jadran Faganeli & Milena Horvat: Živo srebro v območju Idrije in severnega Jadrana .................. 131 Davorin Tome: 3. mednarodni kongres "Ekologija in varstvo evropskih gozdnih sov" ........ 137 OCENE RECENSIONI REVIEWS Colla A., Constantin) M., Cherdol S., Odorico R., Orioîo G., Pisa G., Poldini L., Spoto M., Utmar P., Verginella L., Vidali M. & G. Visintin: Era terra e mare. Gli ambienti marini e costieri de! Friuli - Venezia Giulia (Martina Orlando) ..........................................................................138 Katalog izobraževalnih vsebin (Dag Kleva) ......................139 Atlante degli uccelli svernanti in Campania (Iztok Geister) ..................................................................140 Nova ornitološka revija: Ornlthologia Algirica (Iztok Geister) .............................................................................140 Kazalo k slikam na ovitku ..........................................................................141 Index to pictures on the cover Navodila avtorjem ................................................................................................142 Instructions to authors......................................................................................144 SUPLEMENT Abstracts of the Interdisciplinary Workshop "Pattern and Process in Balkan Biodiversity", Koper, September 25-28 2001 Povzetki z mednarodnega znanstvenega sestanka "Vzorci in procesi v balkanski biodiverziteti" Koper, 25. - 28. september, 2001 1HTIOLOGÍJA ITTIOLOGIA ICHTHYOLOGY ANNALES Ser. hist. nat. • 11 • 2001 • 1 (23) original scientific paper : : UDC.597(262-16} received: 31.5.2001 PRESENCE OF THE GREAT WHITE SHARK, CARCHARODON CARCHARIAS (LINNAEUS, 1758) IN THE CATALONIAN SEA (NW MEDITERRANEAN): REVIEW AND DISCUSSION OF RECORDS, AND NOTES ABOUT ITS ECOLOGY Joan BARRULL & Isabel MATE Lab. Vertebráis Secció ¡c&ialogia, Museo Zoología, E-Q808G Barcelona, Aptat correus 593 E-mail:} ha rrti M @ pie.xtec.es ABSTRACT Occurrences of the great white shark Carcharodon carcharías in the Cataloriian Sea have been poorly reported and at times poorly examined as well. Therefore, historical and contemporary records have been revised and analysed to check on their validity. Furthermore, some brief biological data are presented. Key words: great white shark, Carcharodon carcharías, Catalonian Sea, records, ecology PRESENZA DELLOSQUALO BIANCO, CARCHARODON CARCHARIAS (LINNAEUS, 1758) NEL MARE DELIA CATALOGNA (MEDITERRANEO NORD-OCCIDENTALE): REVISIONE E DISCUSSIONE DELLE SEGNALAZIONl CON NOTE DI ECOLOGIA SINTESI La presenza dello squalo bianco Carcharodon carcharías net Mare délia Catalogna è stata scarsamente riportata e talora non esaminata in dettaglío. Pertanto le segnalazioni storiche ed attuali sono state riviste ed analizzate al fine di valutarne la validité. Vengono ínoltre presentad ai cu ni brevi dati sulla biología délia specie. Parole chiave: Squalo bianco, Carcharodon carchadas, Mare délia Catalogna, segnalazioni, ecología 3 ANNALES • Ser. hist. nat. 11 2001 • 1 (23) ioan 8 ARRUU. & Isabel MATE: TO ESENCE OP THE GREAT WHITE SHARK.....,3-12 INTRODUCTION The great white shark Carcharodon carcharias (Linnaeus, 1758) is a cosmopolitan species inhabiting coastal and temperate waters (Compagno, 1984), Jrt the Mediterranean, it has been mentioned in works of general ichthyology (Cadenat & Blache, 1981; Quero, 1984; Moreno, 1995; Barrull & Mate, 1996; Notarbar-tolo di Sciara & Bianchi, 1998), and it also appears broadly registered in local faunistic compiled works, for instance in the waters of Greece (Papakostantinou, 1988), Italy (Tortonese, 1956), France (Moreau, 1881), and Algeria (Dum6ril, 1865), and also in the Adriatic (Soljan, 1984) and Alboran Seas (Lozano Rey, 1921). Recently, Mojetta ef ai. (1997) and De Maddaiena (1999) prepared a thorough summary of records in Italian waters, and likewise De Maddalena {2000) in the waters of the Northern and Central Adriatic. Recently, Fergusson (1996) made a revision of the white shark's occurrences in the entire Mediterranean. The main objective of the present work is to get acquainted with the presence of the white shark in the Catalonian Sea, as well as to revise and discuss the records of this species. Fig. 1 : Localities of the specimens of great white shark Carcharodon carchadas in the Catalonian Sea (NW Mediterranean). SI. 1: Lokacije osebkov belega morskega volka Carcharodon carcharias v Katalonskem morju (SZ Sredozemlje. 4 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Joan BARRUU & Isabel MATE: PRESENCE Of THE GREAT WHITE SHARK......3-12 MATERIALS AND METHODS The area encompassed by the revision comprises the part of the western Mediterranean Sea known as the Cataionian Sea, whose limits were mapped by Danish Oceanograpbical Expeditions, 1908-1910 (Schmidt, 1912). The Cataionian Sea is a subunit of the Balearic Sea, limited by an imaginary line running from La Nau Cape (38°45'N) to Cervera Cape (42°30'N), including the Balearic Islands (Fig. 1). This region coincides more or less with the authors' usual work area, thus enabling them to draw on a certain familiarity and background that proved invaluable in preparing the present compilation. Data were collected from five main sources: a) books and scientific journals, b) circumstantial articles including photographs of captured specimens, c) sightings reports, d) location and study of material preserved in private collections or natural history museums, and e) collaboration with other researchers and private citizens. For the compilation of bibliographical references and scientific citations within the waters of the study area, it was sufficient to bring up to date the work of Lloris et a/. (1984). In every case, whenever possible, the following data were collected: date and locality of the record; total length (TL) in cm, weight (W) in kg, and sex of the animal; type of record (capture, sighting or stranding). Total length and weight were estimations reported by fishermen. RESULTS The collected information include 26 specimens sighted or captured in the Cataionian Sea between 1878 and 2000 (Tab. 1). A total of 21 cases refer to Balearic Islands, 3 to Castelíó, 1 to Girona and 1 to Barcelona. Pérez Arcas (1878) mentions the capture of a specimen in 1878 along the coast of Valencia, between the Columbretes islands and Castelíó. Surely this was the first documented record in the Cataionian Sea waters, often taken as reference in later works, such as those by Sánchez-Comendador (1904), Ferrer Aledo (1906), Fage (1907), Gibert (1911), De Buen (1935) and Lozano Cabo (1963). The contributions of these authors are not documented neither with date nor capture place, neither with sighting nor beaching of the white shark. Thus we can consider them simple general listings. Lozano Rey (1928) refers to a specimen caught in 1878 "... en las islas Columbretes no lejos de Castellón de la Plana..." ("...off the Columbretes Islands not far from Castellón de la Plana..."). The description of the capture leads us to believe that it could be the same individual as examined by Pérez Arcas due to the same date of capture, fishing place, weight of the animal, the only (small) difference being the total length, surely as a result of unreliable measure units being used. The same author further states in his work records from Mallorca (Balearic Islands), Vi- narós (Castelíó), and "...en distintas partes de nuestro litoral mediterráneo..." ("...in different places along our Mediterranean ■ coast..."), without any documented specification. Fergusson (1996) reported on three captures from- the Columbretes Islands, Castellón and Valencia (Fergusson's cases n° 83, 84 and 85) but they are surely the same catch as reported by Pérez Arcas (1878/. Barrull & Mate (1993-1994, 1996) refer to a specimen captured in the almadraba (enclosed tuna net) off Vilassar de Mar (Barcelona). Two dental pieces of this individual, catalogued with the registration numbers MZB-82-5316 and MZB-82-5317, were deposited in the Museum of Zoology of Barcelona on December 16th 1912 (Fig. 2). These teeth are documental evidence of the first white shark record in Catalonia, and the secónd chronologically dated in the Cataionian Sea. Corbera et ai. (1996) comment on the capture of a specimen off Premia de Mar (Barcelona), but this record is not valid due to an error (Corbera, pers. comm.), and it refers to the animal studied by Barrull & Mate (1993-1994). Samper (1979) points out the capture of a 500 cm long and 1,500 kg heavy female along the coast of Castelíó "...hace ya algunos años..." ("...some years ago..."). Asensi (1980) refers to an individual caught in 1962 off Castelíó as well. This might be the same individual, but as Asensi has never responded to our requirement to confirm this record, we consider it doubtful. Ramis & Terrasa (1988) comment on sighting and capture of 18 individuals with enclosed tuna nets (almadrabas) off Balearic Islands between 1941 and 1976. Most of these records are documented with pictures of the animals and explanations of the fishermen that made the captures (Figs. 3, 4). Further 12 individuals were said Fig. 2 : Teeth of the great white shark Carcharodon carcharías caught in December 1912 in the coastal waters of Vilassar de Mar (Barcelona). (Photo: /. Barrull & I. Mate). SI. 2: Zobovje belega morskega volka Carcharodon carcharías, ujetega decembra 1912 v obrežnih vodah Vi-lassarja de Mara (Barcelona). (Foto: j. Barrull & I. Mate). 5 ANNALES • Ser. hist. nat. • 11 - 2001 • 1 (23) Joan BARRULL & Isabel MATE: PRESENCE OF THE GMAT WHITE SHARK______3-12 Tab. 1: Data on great white sharks registered in the Catabnian Sea. Tab. 1: Podatki o belih morskih volkovih, zabeleženih v Katalonskem morju. No. DATE LOCATiON TL (cm) W(kg) SEX REMARKS REFERENCE 1 01/1878 ¡lies Columbréis (Casteiló) 500 ca. 2300 ? Capture in nets. Published in "La liustracion Espanoia y Americana" on January 22nf! 1878 Pérez Arcas (1878), Lozano Rey (1928) 2 12/1912 Vilassar de Mar (Barcelona) 471 ? ? Capture in enclosed tuna net. Teeth donated by Dr. loan Prim on Decembrer 16th 1912. Reg.no.MZB-82-5316 &MZB-82-5317 Barrul¡& Mate (1993-94) 3 before 1928 Vinarós (Casteiló) ? ? ? Teeth were deposited in the Museo Nacional de Ciencial Naturales de Madrid. Missing at the present time. Lozano Rey (1928) 4 before 1928 Cap de ses Salines -Mallorca (Balears) ? ? ? Capture in a trammel net. Lozano Rey (1928) 5 1941 Ses Caletes des Cap Pinar-Badia de Poiiemja-Maliorca (Balears) 445 900 ? Capture in enclosed tuna net and harpooned. Pursued to the shore and stranding, was killed with an axe. Ramls & Terrasa (1998), M. Martínez (pers. comm.) 6 08/1941 Ses Caletes des Cap Pinar-Badia de Pollen^a-Mallorca (Balears) 600 ca. 2000 ? Sighting. Turned round the long lines eating the captures. M. Martínez (pers. comm.) 7 08/1941 Ses Caletes des Cap Pinar-Badia de Pollenca-Mallorca (Balears) 600 ca. ? ? Sighting. Came with individual no. 6. M. Martínez (pers. comm.) 8 12/1941 Ses Caletes des Cap Pinar-Badia de Pollenca-Mallorca (Balears) 600 1600 F Capture in enclosed tuna nets. Stomach content: a head and two legs of goat Sold for 16.000 pts. M. Martínez (pers. comm.) 9 02-03/1943 Ses Caletes des Cap Pinar-Badia de Pollenca-Mallorca (Balears) 428 800 ? Capture in enclosed tuna nets. Ramis & Terrasa (1998), M. Martínez (pers. comm.) 10 02-03/1943 Ses Caletes des Cap Pinar-Badia de Pollenca-Mallorca (Balears) 523 1500 ? Capture in enclosed tuna nets. Ramls & Terrasa (1998), M. Martínez (pers. comm.) 11 1958 Badia d'Alcúdia -Mallorca (Balears) ? ? ? Capture in enclosed tuna nets. Ramis & Terrasa (1998), M. Martínez (pers. comm.) 6 ANNALES Ser. hist. nat. • 11 • 2001 • 1 (23) loan I3ARKUU. & isabcl MATE: PRESENCE OF THE GREAT WHITE SHARK, ...., 3-12 12 1960-1970 Cala Blava-Badia de Palma - Mallorca (Balears) 700 ca. 2500 F Capture in enclosed tuna nets. Poyatos (pers. comm.) 13 1962? Castelió de la Plana (Castel ló) 500 1500 ? Samper (1979), Asensi (1980) 14 1963 Badia d'Alc.údia -Mallorca (Balears) ? ? ? Capture in enclosed tuna nets. Sold for 17.000 pts. Ramis & Terrasa (1998), M. Martínez (pers. comm.) 15 1967 Cap Ferrutx - Badia d'Alcúdia - Mallorca (Balears) 523 1500 ? Capture in enclosed tuna nets. Stomach content: a dolphin and 4 large tunas. Ramis & Terrasa (1998), M. Martínez (pers. comm.) 16 27/01/1967 Cala Ratjada -Mallorca (Balears) 500 1300 F Capture in enclosed tuna nets. Sold for 10.000 pts. M. Martinez (pers. comm.) 17 06/1968 Cala Ratjada -Mallorca (Balears) ? ? ? Capture in enclosed tuna nets. M. Martinez (pers. comm.) 18 02/1 969 Badia d'Alcúdia -Maliorca (Balears) 523 1500 ? Capture in enclosed tuna nets. Arrived alive at port. Ramis & Terrasa (1998), M. Martinez (pers. comm.) 19 02/1969 Badia d'Alcúdia -Mallorca (Balears) 428 800 ? Capture in enclosed tuna nets. Jaws preserved. Ramis & Terrasa (1998), M. Martinez (pers. comm.) 20 02/1969 Badia d'Alcúdia -Mallorca (Balears) ? 700e ? Capture in enclosed tuna nets. Ramis & Terrasa (1998), M. Martinez (pers. comm.) 21 01/1970 Ses Caletes des Cap Pinar-Badia de Pollenga-Ma Horca (Balears) 460 1000 ? Capture in enclosed tuna nets. Ramis & Terrasa (1998), M. Martinez (pers. comm.) 22 1971 Sa Foradada -Mallorca (Balears) 550 ca. 1500 M Capture in enclosed tuna nets. Poyatos (pers. comm.) 23 1972 Cala Murta - Badia de Poiienfa-Mallorca (Balears) 574 2000 ? Capture in enclosed tuna nets. Ramis & Terrasa (1998), M. Martinez (pers. comm.) 24 02/1976 Cala Murta - Badia de Pollenca-Mallorca (Balears) 488 >1200 > Capture in enclosed tuna nets. Stomach content: half digested ray. Ramis & Terrasa (1998), M. Martinez (pers. comm.) 25 17/11/1992 Platja de la Mar Menuda -Tossa de Mar- (Girona) 475 ? M Stranding, jaws preserved at the CRAM (Premia de Mar). Barrull (1993) 26 08/2000 Cabrera (Balears) 400 ca. ? ? Sighting. Not absolutely confirmed. Jiménez (2000), Poyatos (pers. comm.) to be caught accidentally in the enclosed tuna nets at Cap Ferrutx, Ses Caletes des Cap Pinar, S'lliot des Por-ros, Sa Cova des Bous, and Caia Murta (N£ Maliorca) during the same period, but most of them were not documented. In August 1941, two great white shark were sighted off Ses Caletes des Cap Pinar (Maliorca) (Martinez, pers. comm.). Another individual was captured within the same area in December 1941. It was 6 m long and weighing about 1600 kg (Martinez, pers. comm.). On January 27til 1967, a 5 m long great white shark was caught near Cala Ratjada (Mallorca) (Martinez, pers. comm.). In early June 1968, one individual was taken at the same locality (Martinez, pers. comm.). Fergusson (1996) points out the capture of two individuals in Andratx (Mallorca) in July 1992, adducing a personal comment by j. Piza, veterinary from Marine-land Palafolls (Girona). This record is very doubtful for it 7 ANNALES Ser. hist. nat. • 11 • 2001 • 1 (23) (0.111 BARRULL & Isabel MATE: PRESENCE OF THE GREAT WHITE SHARK...... 3-12 Fig. 5: Specimen stranded on November 17th 1992 on Tossa de Mar (Girona) (Photo: j. More). SI. 5: Osebek, ki je 17. novembra 1992 nasedel na plaži Tossa de Mar (Girona) (Foto:}. More). to the scarce number of records. Encounters are most common at insular sites and in association with pelagic fisheries for large teleosts such as tuna or swordfish. After the disuse of enclosed tuna nets (at the end of the seventies), occurrences have practically disappeared. Among the studied cases, sixteen were reported with the month of capture. The seasonality of records showed an increase of captures during winter months. It is difficult to discuss the seasonal movements due to the scarcity of data. However, as the great white shark migrate seasonally, and its seasonal migration is at least partially influenced by water surface temperature (Casey & Pratt, 1985), it is possible to predict its presence in the months in which superficial waters of the Catalonian Sea are colder, occurring when the surface temperature is 13° C (Margalef, 1989). The thermal tolerance of this species is demonstrated by its latitudinal distribution (Compagno, 1984). The role played by the surface temperature in affecting this distribution might be even more important to smaller specimens. It is possible that small white sharks have more difficulties in maintaining optima! body temperature in colder waters (Goldman ef a!., 1996). This would explain the absence, in the study area, of small free-swimrning and juvenile individuals during the colder months. From among the twenty-two cases of white sharks captured, eighteen were caught in enclosed tuna nets (mandragues). Most probably they were pursuing the tunas that entered the Mediterranean Sea through the Strait of Gibraltar and went, parallel to the coast, to the faying areas. This is a clearly trophic migratory behaviour. The stomach contents of the Mediterranean white sharks denote predation on bony fish (tuna and sword-fish), cartilagineous fish (mainly blue sharks and rnakos), dolphins and turtles (Fergusson, 1996; Mojetta et a!., 1997; De Maddaiena, 1999). in the studied area, the number of cases in which great white shark stomach contents were reported, are few. The specimen caught off Cap Ferrutx (Mallorca) (case num. 15) had a dolphin and four large tunas in its stomach. The specimen caught off Cala Murta (Mallorca) (case num. 24) had a half digested ray, while in case No. 6 a head and two legs of a goat were reported. There are three cases (Nos. 5, 6 and 7) in which the sharks were observed during predation on grouper (Epinephelus guaza), amberjack (Serióla dumerilii), and dolphin fish (Coryphaena hippu-rus), caught in a long-line. Some old fishermen reported of a doll and a dog found in sharks' stomachs (Ramis & Terrasa, 1988). In the Catalonian Sea, the great white shark probably has the same diet as those observed in other parts of the Mediterranean, based primarily on cetaceans, large fishes, and carrion, when occasion arises. Tuna overfishing in the Mediterranean would affect seriously their population (Barrull & Mate, 2000). Fig. 6: The jaw of the white shark stranded in Tossa de Mar (Girona). (Photo: /. Barrull & I. Mate). SI. 6: Čeljust belega morskega volka, nasedlega na plaži Tossa de Mar (Girona). (Foto: J. Barrull & I. Mate). 380 ANNALES Ser. hist. nat. - 11 • 2001 ■ 1 (23) joan BARRULl & Isabel MATE: PRESENCE OF THE GREAT WHITE SHARK.....,3-12 Fig. 3: The jaw of the 800 kg white shark caught in February 1969 off Badia d'Alcúdia (Mallorca). (Photo: S, Terrasa). $f. 3: Čeljust 800 kg težkega belega morskega volka, ujetega februarja 1969 v bližini Badie d'Alcúdie (Mallorca). (Foto: S. Terrasa). seems that Mr. Piza has never been asked about the matter, and nobody in Port d'Andratx couid confirm these catches (Martinez, pers. comm.). Barruli (199,3) and Barruii & Mate (1996) report on the stranding of a 475 cm long male on November 17th 1992 on the Mar Menuda beach in Tossa de Mar (Gi-rona) (Figs. 5, 6). The individual was swimming slowly for at least six hours just below the surface of coastal shallow waters. After midnight the animal was stranded moribund on the beach, dying an hour later (Alegre, pers. comm.). The uncertain fact regarding this record is the total length of the animal, since the members of CRAM (Centre de Recuperació d'Animals Marins) and Marineland Palafolls (Girona) who examined the shark did not measure it with due precision, so that the total length of the specimen couid be anything from 475 to 520 cm (Alegre, pers. comm.). In early August 2000, a large white shark was sighted by fishermen, at nightfall, swimming near their boat. The estimated length was nearly 400 cm (Jiménez, 2000). The Guardia Civil patrol that proceeded to the place of sighting couid not confirm the sighting (Poyatos, pers. comm.). Fergusson (1996) points out the capture of an individual near Tarragona, without any additional data, making reference to the work by De Buen (1926). This record cannot be considered valid either, for the article by De Buen is a general listing of fishes observed off the coast of Morocco and the Balearic islands and, moreover, the species C carcharías is not reported in it. DISCUSSION in the Catalonian Sea, the great white shark seems to prefer the waters of the offshore islands (a total of 21 cases are referred to Balearic Islands), just as established in other places of the Mediterranean, This species can be regarded primarily a coastal shark occurring in waters of the continental shelf, at depths ranging between 200 m and less than 20 m. Although Quignard & Raibaut (1993) point out that the populations of this species have increased in the Gulf of Lion (near the study area) it is likely only an occasional, transient inhabitant of the Catalonian Sea, due Fig. 4: One of the three individuals caught in February 1969 in the waters off Badia d'Alcudia (Mallorca). (Photo: courtesy of "Brisas"). SI. 4: Eden od treh osebkov, ujetih februarja 1969 v obrežnih vodah Badie d'Alcudie (Mallorca). (Foto: z dovoljenjem revije "Brisas"). ANNALES • Ser. hist. nat. 11 • 2001 1 (23) Joan 8ARRULI & Isabel MATE: PRESENCE OE THE GREAT WHITE SHARK,.....3-12 The size of sharks was reported in many cases, but the manner by which lengths were obtained is often unknown. Solely it is possible to suggest that the average of total length for the recorded specimens ranges from 42G cm to 600 cm. The dimensions of the registered sharks indicate that they were subadults and adults, since they reached the sizes given in bibliography for these development stadiums (Francis, 1996; Pratt, 1996). Only in five cases the sex of the specimens was reported: three of them were females and two were males. With so few data it is not possible to find evidence about sexual segregation in the area. There is a total absence of records of small free-swimming and juvenile individuals, although small white sharks could be confused with Isurus species by fishermen. Neither have there been any cases of pregnant females, and no phenomena related with reproduction. Everything seems to indicate that the Catalonian Sea is not a suitable reproductive area. Concerning this matter, Cigafa-Fulgosi (1990), Fergusson (1996) and Mojetta eta!. (1997) suggested that the Sicily Channel may be considered a nursery area for this species, but Barrull & Mate (2000) question the assertion of a Mediterranean breeding area, concluding that more research is needed in this respect. Many of the white sharks captured were landed and sold. Regarding Nos. 4, 8 and 16, specimens were sold for 17000, 16000 and 10000 pesetas (US $ 87.9, 82.7 and 51.7), respectively. In the studied area, the carcasses of the large sharks caught are usually dismembered and sold. This fact makes it difficult to obtain detailed information about these animals. No injuries or fatal attacks on humans have been reported so far. Obviously, fortuitous encounters with this species in the Catalonian Sea are extremely unlikely. CONCLUSIONS Creat white shark is very likely merely an occasional and transient inhabitant of the Catalonian Sea. It seems to prefer the waters of the offshore islands. The seasonality of records showed an increase during the months of winter, when they are in search for colder waters. Usually, their occurrence is closely associated with pelagic fisheries. In the Catalonian Sea they feed primarily on tunas, dolphins, rays and carrion. Ail individuals reported are large specimens, adults or subadults. No injurious or fatal attacks on humans are attributable to this species in the studied area. The authors wish to underline the importance of a continual collecting of new and historical data on the occurrence of the great white shark in the Catalonian Sea, as this may contribute towards a better understanding of this species. ACKNOWLEDGEMENTS We wish to thank Martí Martínez, Juan Poyatos, joan Carles Sabrafin, and Ferran Alegre the providing records and information. We would also like to thank the magazine "Brisas", Sebastián Terrasa, and jaume Moré for the courtesy of some pictures, and Dr. Aíessandro De Mad-dalena for translating the abstract into Italian. POJAVLJANJE BELEGA MORSKEGA VOLKA CARCHARODON CARCHARÍAS LINNAEUS, 1758) V KATALONSKEM MORJU (SZ SREDOZEMLJE): PREGLED ZAPISOV iN BELEŽKE O NJEGOVI EKOLOGIJI Joan BARRULL & Isabel MATE Lab. Vertebráis Secció ictiología, Museo Zoología, E-08080 Barcelona, Aptat correus 593 E-mail: jbarruli@pie.xtec.es POVZETEK Beli morski volk Carcharodon carcharías (Linnaeus, 1758} je kozmopolitska vrsta, živeča v obrežnih zmerno toplih vodah. V Sredozemlju je omenjana v splošni ihtiološki literaturi, zabeležena pa je tudi v lokalnih favnističnih kompilacijah. Pričujoči članek obravnava pojavljanje belega morskega volka v Katalonskem morju z revizijo podatkov, zabeleženih v zvezi s to vrsto v tem območju. Zbrane informacije obsegajo 26 osebkov, opaženih aH ujetih med letoma 1878 in 2000. Pérez Arcas (1878} navaja ujetje enega osebka leta 1878 v bližini Valencije med otoki Columbretes in Casteilójem, kar je bil brez dvoma prvi dokumentirani zapis v Katalonskem morju o tej vrsti. Tudi Lozano Rey (1928) omenja belega morskega volka, ujetega leta 1878, in glede na njegov opis gre verjetno za osebek, o katerem je poročal že Arcas. Barrull & Mate (1993-1994, 1996) opisujeta osebek, ki se je decembra 1912 ujel v mrežo tunaro v bližini Vilassarja de Mara (Barcelona). Samper (1979) opozarja na ujetje samice v bližini 10 ANNALES ■ Ser. hist. nat. • 11 2001 ■ 1 (23) Joan BARRULi & isabei MATE: PRESENCE OE THE GREAT WHITE SHARK, 3-12 Castelloja, najbrž v letu 1962. Ramis & Terrasa (1988) navajata 18 osebkov; ujetih s tunaro v bližini Saharskih otokov med letoma 1941 in 1976. Barrull (1993) in Barrull & Mate (1996) poročata o samcu, ki je 17. novembra 1992 nasedel na plaži Mar Menuda v Tossi de Mar (Girona). Nekateri podatki iz literature (Asensi, 1980; Corbera et a L, i 996; Fergusson, 1996) so bili na novo pregledani in analizirani, ne pa tudi potrjeni. Kar zadeva Katalonsko morje, se zdi, da se beli morski volk najraje zadržuje v otoških vodah (21 opažanj je iz območij Balearskih otokov). Sezonskost zapisov kaže na njihovo povečano pojavljanje v zimskih mesecih, ko beli morski volkovi iščejo hladnejše vode. Sicer pa je njihovo pojavljanje največkrat povezano z ribarjenjem na odprtem morju. V Katalonskem morju se prehranjujejo s tu nami, delfini, ražami in, če le mogoče, z mrhovino. V vseh primerih so bili opaženi ali ujeti bolj ali manj odrasli osebki. Zabeležen ni bil niti en sam svobodno plavajoči mladostni osebek, kot tudi ne breja samica ali kar koli, kar bi lahko povezali z razmnoževanjem. Tako vse kaže, da Katalonsko morje ni primerno razmnoževalno okolje za to vrsto. Belemu morskemu volku niso bili pripisani nobeni pogubni napadi na človeka v raziskovanem območju. Avtorja opozarjata na velik pomen nadaljnjega zbiranja novih in zgodovinskih podatkov o pojavljanju belega morskega volka v Katalonskem morju, saj bi to lahko pripomoglo k veliko boljšemu poznavanju te vrste. Ključne besede: beli morski volk, Carcharodon carcharias, Katalonsko morje, zapisi, ekologija REFERENCES Asensi, J. M. (1980): El tiburón. Thor, Barcelona. Barruil, J. (1993): Polémica sobre la presencia de tiburón blanco en el Mar Catalán. Quercus, 87, 18-19. Barruil, }, & I. Mate (1993-1994): Cita histórica de tiburón bianco Carcharodon carcharías (Linnaeus, 1758), en el mar Catalán (mar Mediterráneo), documentada con dientes de la mandíbula. Mise. Zoo!., 17, 283-285. Barrull, J. & I. Mate (1996): Els íaurons deis Pa'ísos Catalans. Pórtíc, Barcelona. Barruil, & I. Mate (2000): Inclusion of Great White Shark Carcharodon carcharías in Apendix I. Proposal 11.48. In: IUCN Analyses of Proposals to Amend the CITES Appendices. !UCN Species Survival Commission and TRAFFIC Network for the Eleventh Meeting of the Conference of the Parties to CITES. IUNC-The World Conservation Union, Gland, Switzerland. Cadenat, J. & j. Blache (1981): Faune Troptcale. Requins de Méditerranée et d'Atlantique, Off. Rech. Scien. Tech. Outremer, 21, 1-330. Casey, J. G. & H. L. Pratt (1985): Distribution of the white shark, Carcharodon carcharias, in the western North Atlantic. Mem. South Calif. Acad. Sci., 9, 2-14. Cigala-Fulgosi, F. (1990): Predation (or possible scavenging) by a great white shark on an extinct species of bottlenosed dolphin in the Intalian Pliocene. Tertiary Research, 12(1), 17-36. Compagno, L. V, J (1984): FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of sharks species known to date. Part 1. Hexanchiformes to Lamniformes. FAO Fish. Synop., 125, 4, 1-249. Corbera, J., A. Sabates & A. Garcia-Rubies (1996): Peces de ia Península Ibérica. Planeta, Barcelona. De Buen, F. (1926): Catálogo ictiológico del Mediterráneo español y de Marruecos. Res. Campañas. Int. Inst. Español Oceanogr., 2, 153-161. De Buen, F. (1935): Fauna ictiológica. Catálogo de peces ibéricos: de la planicie continental, aguas dulces, pelágicas y de los abismos próximos. Primera Parte. Notas Resum. Instituto Español Oceanografía, ser. II, 88,1-89. De Maddalena, A. (1999): Records of the Great White Shark in the Mediterranean Sea. Milano, private publication. De Maddalena, A. (2000): Historical and contemporary presence of the great white shark, Carcharodon carcha -n'as (Linnaeus, 1758), in the Northern and Central Adriatic Sea. Annales, 19, 3-18. Duméril, A. H. A. (1865): Historie naturaile des poissons ou ichthyologle générale. Roret, Paris. Page, L. (1907): Essai sur la faune des poissons del Iles Baléars et description de quelques espèces nouvelles. Archives de zoologie expérimentale et générale, IV sér., 7, 69-73. Fergusson, I. (1996): Distribution and autoecology of the white shark in the Eastern North Atlantic Ocean and the Mediterranean Sea. In: Klimley, A. P. & D. G. Ainley (eds.): Great White Sharks: The Biology of Carcharodon carcharías. Academic Press, San Diego, 321-34.5. Ferrer Aledo, J. (1906): Catálogo de los peces de Menorca. Imprenta el Porvenir del Obrero, Mahón. Francis, M. ?. (1996): Observations on a pregnant white shark with a review of reproductive biology. In: Klimley, A. P. & D. G. Ainley (eds.): Great While Sharks: The Biology of Carcharodon carcharias. Academic Press, San Diego, 157-172. 11 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Joan BARRUU.& Isabel MATE: PRESENCE Of THE GREAT WHiTE SHARK, ...., 3-12 Cibert, A. M. (1911): Fauna ictiológica de Catalunya. Cata lech rahonat dels peixos observats en el litoral y en Ies aygues dolfes catalanes. Sutil. ínst. Cat. Hist. Nat. (2- época), Any VIH, 1911(1), 6, 89-95. Goldman, K. J., S. D. Anderson, J. E. McCosker & A. P. Klimley (1996): Temperature, 5wimming Depth, and Movements of a White Shark at the South Farallons Islans, California. In: Klimley, A. P. & D. G. Ainley (eds.): Great White Sharks: The Biology of Carcharodon carcharías. Academic Press, San Diego, 111-120. Jiménez, J. (2000): Avistado un tiburón blanco de casi cuatro metros en aguas de Cabrera. Última Hora de Baleares, 20/08/00. Lioris, D., J. Rucabado, Ll. Del Cerro, F. Portas, M. Demestre & A. Roig (1984): Tots els peixos del Mar Catalá. I. Llistatde cites i referéncies. Treballs Soc. Cat let. Herp., 1, 8-212. Lozano Cabo, F. (1963): Nomenclatura Ictiológica. Nombres científicos y vulgares de los peces españoles, instituto Español Oceanografía, 31, 1-271. Lozano Rey, L. (1921): Datos para la ictiología marina de Melilla. Museo Nacional de Ciencias Naturales, Madrid. Lozano Rey, L. (1928): Ictiología ibérica (Fauna Ibérica). Peces (Generalidades, Ciclostomos y Elasmobranquios). Mus. Nac. Ciencias Nat., 1, 1 -692. Margalef, R. (1989): El Mediterráneo Occidental. Omega, Barcelona. Mojeíta, A., T. Storaí & M. Zuffa (1997): Segnalazioni di squalo bianco (Carcharodon carcharías) in acque italiane. Quad. Civ. Staz. Idrobiol, 22, 23-38. Moreau, E. (1881): Histoirie naturelle des poissons de la France. Masson, Paris. Moreno, }. A. (1995): Guía de ios tiburones de aguas ibéricas, Atlántico Nororiental y Mediterráneo. Pirámide, Madrid. Notarbartolo di Sciara, J. & I. Bianchi (1998): Guida degli squali e delle razze del Mediterráneo. Franco Muzzio, Padova. Papakonstantinou, C. (1988): Fauna Graeciae ¡V. Check-list of marine fishes of Greece. Hellenic Zoological Society, Athens. Pérez Arcas, L. (1878): Nota sobre los peces escuálidos Carcharodon carcharías (Carcharías lamía). Anales de la Sociedad Española de Historia Natural. Actas, 7, 9-19. Pratt, H. L. (1996): Reproduction in the male white shark, in: Klimley, A. P. & D. G. Ainley (eds.): Great White Sharks: The Biology of Carcharodon carcharías. Academic Press, San Diego, 13Î-138. Quéro, J. C. (1984): Lamnidae. In: Whithehead, P. J. P., M. L. Bauchot, j. C, Hureau, j. Nielsen & E. Tortonese (eds.}: Fishes of the North-eastern Atlantic and the Mediterranean, F NAM. Vol. 1. UNESCO, Paris, 83-88. Quignard, J. P. & A. Raibaut (1993): Ichthyofaune de la côte Languedocienne (Golf du Lion). Modifications faunistiques et démographiques. Vie Milieu, 43(4), 191-195. Ram i s, D. & S. Terrasa (1988): Tiburones en Mallorca. Brisas, 55, 5-12. Sánchez-Comendador, A. (1904): Catàiech ciels peixos observats en el litoral de Barcelona. Butll. înst. Cat. Hist. Nat. (2a época), 3-4, 25-32. Samper, A. (1979): Tiburones y grandes peces. Mar-rajera II. Plaza & Janes, Barcelona. Schmidt, j. (1912): Mediterranean Bramidae. Rep. Danish Ocean, exped. 1908-10, Medit, il(6), 6. Soljan, T, (1948); Ribe Jadrana, Fauna i Flora jadrana, 1. Institut za oceanografiju i ribarstvo, Split. Tortonese, E. (1956): Fauna d'italia. Leptocardia, Ciclo-stomata, Selachii. Calderini, Bologna. 12 ANNALES • Ser. hist. nat. ■ 11 • 2001 • 1 (23) professional paper UDC 591.5:597(262) received: 13.5.2001 IN RELATION TO THE CAPTURES OF A GREAT WHÍTE SHARK, CARCHARODON CARCHARIAS (LINNAEUS, 1758), AND A SHORTFIN MAKO, ISURUS OXYRINCHUS RAFiNESQUE, 1809, ¡N THE MESSINA STRAIT Antonio CELONA Aquastudio Research institute, (T-98121 Messina, Via Trapani 6 Nicola DONATO Dipartimento di Biología Anímale ed Ecología Marina, Universitá di Messina, IT-98166 Messina, Via Sperone 31 Aiessandro DE MADDALENA Italian Great White Shark Data Bank {Banca Dati Italiana Squalo Bianco), iT-20144 Milano, Via V. Foppa 25 E-mail: ademaddalena@tiscatinet.it ABSTRACT We developed a crítica! revision of some incorrect data recently reported by Fergusson et a!. (2000} in relation to the two captures of sharks in the waters near Ganzirri (Messina Strait, Italy) and their stomach contents. A specimen caught in 1963, reported by Fergusson et ai. (2000) as a white shark Carcharodon carcharías having in its stomach a marine turtle Caretta caretta, was in fact a shortfin mako Isurus oxyrinchus having in the stomach a bow-net and some buttons. The other, a white shark caught in 1965, had in its stomach remains of marine turtle Caretta caretta, and not an ocean sunfish Mola mola as erroneously reported by Fergusson et ai. (2000). Key words: Carcharodon carcharías, Isurus oxyrinchus, Caretta caretta, Mola mola, Mediterranean Sea IN RELAZIONE ALLE CATTURE Di UNO SQUALO BIANCO, CARCHARODON CARCHARIAS (UNHAWS, 1 758), E DI UNO SQUALO MAKO DALLE PINNE CORTE, ISURUS OXYRINCHUS RAFINESQUE, 1809 NELLO STRETTO DI MESSíNA SÍNTESl Viene svolta la revisione critica di alcuni dati erronei recentemente riportati da Fergusson et a!. (2000) in relazio-ne a due catture di squali nelle acque di Ganzirri (Stretto di Messina, Italia) ed ai loro contenuti stomacali. Un esemplare catturato nel 1963, riportato da Fergusson et al. (2000) come uno squalo bianco Carcharodon carcharías avente nello stomaco una tartaruga marina Caretta caretta, era in res/ta uno squalo mako dalle pinne corte Isurus oxyrinchus avente nello stomaco una nassa e dei bottoni. L'altro, uno squalo bianco preso nel 1965, aveva nello stomaco resti di tartaruga marina Caretta caretta, e non un pesce luna Mola mola come erróneamente riportato da Fergusson et al. (2000). Parole chía ve: Carcharodon carcharías, Isurus oxyrinchus, Caretta caretta, Mola mola, Mare Mediterráneo 13 ANNALES • Ser. hist. nat. ■ 11 • 2001 • 1 (23) Antonio CEI.ONA eta!.: IN RELATION TO THE CAPTURES OF A GREAT WHITE SHARK. ... 13-16 INTRODUCTION f-'ergusson ef al. (2000) recently presented an analysis of some cases of predation by white sharks, Carcba-melon carcbarias (Linnaeus, 1758), upon marine turtles in the Mediterranean Sea, including the case reported as the first record of predation (or scavenging) by white shark upon ocean sunfish, Mola mola (Linnaeus, 1758)., Since in this work we noticed remarkable inexactness regarding the two captures of sharks in 1963 and 1965 in the Messina Strait, we decided to present herewith the direct report by Nicola Donato, who was the author of both these captures. RESULTS AND DISCUSSION In relation to a shortfin mako, Isurus oxyrinchus Rafi-nesque, 1809, caught in June 1963 In Fergusson ef al. (2000) there is a detailed report of the capture of a shark indicated to be a 350 cm TL white shark, harpooned ca. 3 km offshore from Ganzirri in June 1963. Fergusson et al. (2000) wrote that in its stomach remains of a marine turtle, Caretta caretta (Linnaeus, 1758), were found and they furnished precise details of the damage sustained by the carapace as a consequence of the shark's bite. Strangely, Fergusson ef al. (2000) specify several times to have collected this testimony directly from the author of the shark capture, Nicola Donato (that is also a co-author of the present work), as personal communication to Ian K. Fergusson and Mark A. Marks. This statement is not true, and the report, about the species of shark and its stomach contents is inexact. It is curious to note that Mojetta ef al. (1997) mentioning the same specimen wrote that it had a dolphin in its stomach, indicating a personal communication of Ian K. Fergusson as the source of this data. For this reason we decided to expose the true report of this capture. The shark in question was in fact a shortfin mako, Isurus oxyrinchus Rafinesque, 1809, and not a white shark. The specimen was sighted some hundreds of meters offshore from Contrada Principe (Ganzirri), it was approached with a mid-sized boat, and when it was harpooned by Nicola Donato it reacted violently. Once captured, neither a marine turtle as written by Fergusson et al. (2000) nor a dolphin as indicated by Mojetta et al. (1997) was found in Its stomach, but a small bow-net, similar in shape to those used for capturing lobsters, beside some large buttons sewed on pieces of a dark cloth, apparently coming from the kind of coat commonly worn by seamen. The specimen was never measured but it was estimated by Donato to be about 320 cm long and weighing about 250 kg. in relation to a great white shark, Carcharodon carcharías (Linnaeus, 1758), caught on March 9"' 1965 Again, Fergusson et al. (2000) reported on another case, claimed as the first record of predation (or scavenging) by white shark upon ocean sunfish, Mola mola. The authors refer to the capture of a more than 500 cm TL great white shark on March 9'1' 1965, taken near Ganzirri and again performed by Nicola Donato. Fergusson ef al. (2000) report that the shark was first observed near the breakwater by Donato with its boat some 100 m offshore and then harpooned. !n its stomach was a freshly-ingested adult ocean sunfish, Mola mola, measuring about 2 m TL, bitten into three sections (head, mid-trunk and posterior with dorsal fin, anal fin and cla-vus). As in the previous case, Fergusson ef al. (2000) in n % w | "i íi': H, ÍV1 •"-■'!<í'..... .-''I -........... ■ . i*.* I . Igiiigps * Jf Fig. 1: Nicola Donato showing the set of jaws of the great white shark, Carcharodon carcharias (Linnaeus, 1758), caught by him near Ganzirri (Sicily, Italy) on March 9*' 1965. (Photo: A. Celona). Si 1: Nicola Donato med razkazovanjem čeljusti belega morskega volka Carcharodon carcharias (Linnaeus, 1758), ujetega 9. marca 1965 v bližini Ganzirrija (Sicilija). (Foto: A. Celona). 14 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Antonio CElONAef ai.: IN RELATtON TO THE CAPTURES OF A GREAT WHITE SHARK.....13-16 ciicate the source of the data to be a persona! communication of Nicola Donato to Ian K. Fergusson and Mark A. Marks; but this is not true, and this second report, too, is incorrect. The truth as far as this capture is concerned is the following. The white shark was first observed pursuing a school of mullets, Mugil sp., only a few meters from the shore, in very shallow waters, where it almost touched the sea-bottom with the ventral surface of its body, while its dorsal part was out of the water. As the shark moved towards offshore waters, it was followed by the boat. It was quickly caught and Nicola Oonato harpooned It about 40 meters from the coast. The harpoon penetrated through the posterior part of the trunk, at about mid-point between the first dorsal fin and the caudal fin. The shark hauled the boat for about four hours, crossing the Messina Strait three times before dying. In its stomach several parts of marine turtle, Caretta carelta, were found, as well as remains of bony fishes and other unidentified remains. The measurements on this specimen were taken by Prof. Sebastiano Genovese of the University of Messina, who stated the length at 620 cm and the weight of 1200 kg. This weight is also indicated on a plate fixed on the set of jaws preserved in Ganzirri, in the Istituto di Idrobiologia del-j'Universita di Messina (Fig. 1). This capture was reported previously by the following authors: Anonymous (1965), Berdar & Rlccobono (1986), Giudici & Flno (1986), Fergusson (1996), Mo-jetta eta!. (1997) and De Maddalena (1999). Mojetta et a!. (1997) were the first to report correctly that the stomach of this specimen contained remains of marine turtle, but they wrongly indicated that the capture was made on ls! April. About the size of the shark, Anonymous (1965) report a length of 5 m, a weight of 8 q and a first dorsal fin height of 160 cm, while Berdar & Rlccobono (1986) reports a length of 620 cm, a pectoral fin length of 120 cm and a first dorsal fin height of 160 cm; the first dorsal fin height reported by both sources is clearly unacceptable, while the weight of 8 q has to be referred to the gutted and beheaded specimen. On the basis of the two photographic evidences examined by the authors (Fig. 2), the total length of the specimen could be something less than the reported one, apparently around 560 cm, and it seems reasonable to infer that the reported 620 cm length was obtained measuring the shark over the curve of the body instead of in a straight line. This could also explain the relatively low weight. Unfortunately it was not possible to gather more information about the shark in question, since Sebastiano Genovese and Adolfo Berdar are no longer with us. The jaws were examined by the authors and the measurements on the upper and lower anterior teeth were taken following Mollet etai. (1996) (Tab. 1). Teeth rows are 12-12 above and 12-1 2 below. Tab. I: Measurements of the upper and lower anterior teeth of the great white shark, Carcharodon carcharías (Linnaeus, 1758), caught near Ganzirri on March 9lh 1965. Tab. 1: Mere zgornjih in spodnjih sprednjih zob belega morskega volka Carcharodon carcharías (Linnaeus, 1758), ujetega blizu Ganzirrija 9, Marca 1965. First upper anterior toosh enameloid height (UA1 El) 31 mm First upper anterior tooth enameloid width (UA1EW) 40 mm Second upper anterior tooth enameloid height (UA2E1) 28 mm Second upper anterior tooth enameloid width (UA2EW) 39 mm First lower anterior tooth enameloid height (LAI El) 22 mm First lower anterior tooth enameloid width (LAI EW) 26 mm Second lower anterior tooth enameloid height (LA2E1) 33 mm ¡Second lower anterior tooth enameloid width (LA2EW) j30 mm CONCLUSIONS With this work we feel to have definitely clarified the series of mistakes that accompanied the reports of these two captures in the previous literature. Concerning the ocean sunfish, remains of this animal, belonging to small specimen (20-30 kg in weight), have been found on some occasions in the stomachs of blue sharks, Prionace glauca (Linnaeus, 1758), caught in the Messina Strait but, to our knowledge, never in specimens of Carcbarodon carcharias. Fig. 2: Great white shark, Carcharodon carcharias (Linnaeus, 1758), caught by Nicola Donato near Ganzirri (Sicily, Italy) on March 9th 1965. (Photo reproduced by kind permission of Antonino Donato). SI. 2: Beli morski volk Carcharodon carcharias (Linnaeus, 1758), ki ga je 9. marca 1965 ujel Nicola Donato v bližini Ganzirrija (Sicilija). (Reprodukcija fotografskega posnetka s prijaznim dovoljenjem Antonina Donata). 15 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Antonio CELONA el ah IN RELATION TO THE CAPTURESOF A GREAT WHITE SHARK, 13-16 ACKNOWLEDGEMENTS following persons: Franco Gazzara, Anfonino Donato, Francesco Riccobono, Marco Zuffa and Gildo Cava-The authors would like to express their thanks to the nelii. V ZVEZI Z UJETJEM BELEGA MORSKEGA VOLKA CARCHARODON CARCHARIAS (LINNAEUS, 1758) iN ATLANTSKEGA MAKA ISURUS OXYRiNCHUS RAFINESQUE, 1809 V MESSINSKEM PREUVU Antonio CELONA Aquastudio Research institute, IT-98121 Messina, Via Trapani 6 Nicola DONATO Dipartimento di Biologia Animaie ed Ecologia Marina, University di Messina, IT-98166 Messina, Via Sperone 31 Alessandro DE MADDALENA Italian Great White Shark Data Bank (Banca Dati Jtaiiana Squalo Bianco), ¡T-20144 Milano, Via V. Foppa 25 E-ma i I: a demadda I ena @ ti sea I met. it POVZETEK Avtorji pričujočega članka želijo napraviti kritični pregled (napačnih) podatkov v poročilu Eergussona et af. (2000) v zvezi z ujetjem dveh morskih psov v vodah blizu Ganzlrrija (Messinski preliv, Italija) in vsebino njunih želodcev. V letu 1963 ujeti pes, ki naj bi bil po poročanju Fergusona et al. (2000) beli morski volk Ca rc h a rod on car-charias s kareto Caretta caretta v želodcu, je bil v resnici atlantski mako Isurus oxyrinchus z majhno vršo In nekaj gumbi v želodcu. DrugI pes - beli morski volk, ujet leta 1965 je imel v želodcu ostanke karete Caretta caretta, ne pa morskega meseca Mola mola, kot so napačno poročali Eergusson et al. (2000). Ključne besede: Carcharodon carcharias, Isurus oxyrinchus, Caretta caretta, Mola mola, Mediterranean Sea REFERENCES Anonymous (1965): Uno squalo tigre catturato dai pes-catori neilo Stretto. Gazzetta del Sud, 10 Marzo 1965, Messina. Berdar, A. & F. Riccobono (1986): Le meraviglie deiio Stretto di Messina. EDAS, Messina. De Maddalena, A. (1999): Records of the great white shark in the Mediterranean Sea. Milano, private publication. Fergusson, I. K. (1996): Distribution and autecology of the white shark in the Eastern North Atlantic Ocean and the Mediterranean Sea, In: Klimley, A. P. & D. G. Ainley (eds.): Great white sharks. The biology of Carcharodon carcharlas. Academic Press, San Diego, 321-345, Fergusson, I. K., L. J. V. Compagno & M. A, Marks (2000): Predation by white sharks Carcharodon carcharias (Chondrichthyes: Lamnidae) upon chelonians, with new records from the Mediterranean Sea and a first record of the ocean sunfish Mola mola (Osteichthyes: Molidae) as stomach contents. Environmental Biology of Fishes, 58. Kluwer Academic Publishers, Netherlands, 447-453. Giudici, A, & F. Fino (1989): Squali del Mediterráneo. Atlantis, Roma. Mojetta, A., T. Storai & M. Zuffa (1997): Segnalazioni di squalo bianco (Carcharodon carcharias) in acque iialiane. Quaderni della Cívica Stazione Idrobiologica di Milano, 22. Civica Stazione Idrobiologica, Milano, 23-38. Mol let, H. F., G. M. Cailliet, A. P. Klimley, D. A. Ebert, A. D. Testi & L. J. V. Compagno (1996): A review of length validation methods and protocols to measure large white sharks. In: Klimley, A. P. & D. G. Ainley (eds.): Great white sharks. The biology of Carcharodon carcharias. Academic Press, San Diego, 91-108. 16 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) original scientific paper UDC 597.3(262) received: 5.7.2001 MORPHOMETRÍCS OF NEONATE VELVET BELLY, ETMOPTERUS SPiNAX (LiNNAEUS, 1758) Alessandro DEMADDALENA Italian Great White Shark Data Bank (Banca Dati italiana Squalo Bianco), 1T-20145 Milano, via L. Ariosto 4 E-mail: a i:k: rri a 5.0 8.98 P2L pelvic length 9.0 11.3 13.5 17.0 9.80 P2A pelvic anterior margin 7.0 5.0 7.0 10.0 5.62 P2B pelvic base 7.0 7.8 8.0 8.5 6.19 P2H pelvic height 3.5 2.5 4.5 4.5 2.90 P2I pelvic inner margin length 2.0 3.5 5.5 8.5 3.60 P2P pelvic posterior margin length 4.5 5.0 8.0 8.5 4.96 HDH head height 10.0 8.0 14.0 9.0 8.07 TRH trunk height 10.5 8.0 12.0 8.5 7.73 20 ANNALES ■ Ser. hist. nat. 11 2001 ■ 1 (23) Alcraandro DEMADDALCNA & Uiigi PISCITELU: MORPHOMETRY OF NEONATE VELVET BEll.Y.....17-22 A8H abdomen height 9.8 7.0 11.0 11.0 7.59 TAH tail height 7.2 6.5 9.5 9.0 6.29 CPU caudal peduncle height 3.0 3.5 5.0 4.5 3.10 DPO 1st dorsal midpt.-peivic origin 13.0 15.0 18.0 20.0 12.86 PDI pelvic midpt.-l5t dorsal insertion 16.0 18.5 24.8 29.0 17.01 PDO pelvic midpt.-2nd dorsal origin 4.0 1.5 2.6 2.5 2.13 MOL mouth length 3.5 3.8 4.0 4.0 3.03 MOW mouth width 8.0 9.0 9.0 10.0 7.12 NOW nostril width 3.5 2.8 4.0 3.8 2.77 INW internarial space 2.8 3.5 4.4 4.0 2.87 ANF anterior nasal fiap length 0.7 1.2 1.0 1.1 0.79 CLO clasper outer length X X 2.0 2.0 1.36 CLI clasper inner length X X 6.0 7.5 4.56 CLB clasper base width X X 1.0 1.0 0.67 !NO interorbita! space 10.8 12.0 13.0 13.2 9.67 SPL spiracle length 1.3 1.3 1.5 2.5 1.27 ESL eye spiracle space 2.2 1.0 2.0 1.5 1.33 HDW head width 13.0 14.0 17.0 18.0 12.12 TRW trunk width 9.5 9.0 12.0 12.0 8.32 A8W abdomen width 7.5 " 7.0 10.5 11.0 6.97 TAW tail width 5.0 3.5 7.0 7.0 4.33 CPW caudal peduncle width 2.3' 2.2 3.0 2.6 1.98 MORFOMETRIJA NOVOSKOTEN1H ČRNIH TRNEŽEV ETMOPTERUS SPINAX (LINNAEUS, 1 758} Alessandro DE MADDA L ENA Italian Great White Shark Data Bank (Banca Dati italiana Squalo Bianco), IT-20145 Milano, via L. Ariosto 4 E-mail: ademaddatena@t.i$ca!inet.i: Luigi PISCITELU Mercaio Ittico, IT-20137 Milano, viaie Molise 62 E-mail: dotlulu@Eiscalinet.it POVZETEK Avtorja navajata biološke podatke o štirih novoskotenih črnih trnežih Etmopterus spinax (Linnaeus, 1758), ujetih v začetku leta 2000 v bližini Viareggia (Ligursko morje). Osebki (dva samca in dve samici) so bili dolgi 108, 110, 142 in 153 mm. Predstavljena je morfometrija vseh štirih trnežev. Avtorja sklepata, da je ta del morja v bližini Viareggia razmnoževalno okolje za to vrsto morskega psa. Ključne besede: črni trnež, Etmopterus spinax, razmnoževanje, Ligursko morje 21 ANNALES Ser. hist. nat. • 11 • 2001 • 1 (23) Aíessaridro DEMAPDALENA & luigi PISCITEL LI: MORPHOMETRY OI: NEONATE VELVET 8EILY, ...,17-22 REFERENCES Barrulí, )., i. Mate & M. Bueno (1999): Observaciones de tiburones (Chondricbtyes Euseíachii) en aguas de Cataluña (Mediterráneo NO), con algunos aspectos generales de su Ecofogía. Scientia gerundensís, 24, 127-151. Bauchot, M. L. (1987): Requins, ¡n: Fischer, W., M. Schneider & M.-L Bauchot (eds.): Fiches FAO d'identification des espèces pour les besoins de la peche. (Révision I). Méditerranée et Mer Noire. Zone de peche, 37, Vol. 2. Vertébrés. Rome, CEE, FAO. 767-843. Bigelow, H. B. & W. C. Schroeder (1957): A study of the sharks of the suborder Squaloidea. Buîl. Mus. Comp. Zool, Harv. Univ., 117(1), 1-150. Cadenat, ). & Blache (1981): Requins de Méditerranée et d'Atlantique (plus particulièrement de la Côte Occidentale d'Afrique). Faune Tropicale, 21, 1-330. Compagno, L. J. V. (1984): FAO Species Catalogue. Vol. 4. Sharks of the World - an annotated and illustrated catalogue of shark species known to date. Parts 1-2. FAO Fish. Synop., 125, Rome, FAO, 1-655. Costa, F. (1991): Atlante dei Pesci dei mari itafiani. Mursia, Milano. KabasakaE, H. & N. Unsai (1999): Observations on Etmopterus spinax (Pisces: Squalidae), from the northeastern Aegean Sea. Biljeske (Notes), 81,1-11. Tortonese, E. (1956): Fauna d'italia vol. Ii. Leptocardia, Ciclostomata, Selachii. Caiderini, Bologna. Vacchi, M. & L. Relini Orsi (1979): Aspetti riproduttivi in Etmopterus spinax L. (Cbondrichthyes, Squalidae). Quad. Civ. Staz. idrobioi. Milano, 7, 63-74. 22 ANNALES Ser. hist. nat. 11 2001 • 1 (23) original scientific paper UDC 574:5:591.5(262) received: 13.6.2001 FIRST CONFIRMED RECORD OF ANGULAR ROUGHSHARK OXYNOTUS CENTRINA (LINNAEUS, 1 758} PREDATSON ON SHARK EGG CASE OF SMALL-SPOTTED CATSHARK SCYLIORHINUS CANÍCULA (LINNAEUS, 1 758} IN MEDITERRANEAN WATERS Joan 8ARRULL & Isabel MATE Lab. Vertebráis Seccíó ictiología, Museo Zoología, ü-08080 Barcelona, Aptaí correus 593 E-mail: jbarruli@pie.xtec.es ABSTRACT The stomach content examination of two male angular roughshark individuals Oxynotus centrina captured in Barcelona's coastal waters on November 2000 and January 2001 revealed the presence of yolk sacks and embryos from the small-spotted caishark Scyliorhinus canicula. Up to date, this is the first confirmed record of small-spotted catshark egg prédation In the Mediterranean waters. Key words: Oxynotus centrina, Scyliorhinus canicula, prédation, shark egg case, embryos, Mediterranean Sea PRIMA SEGNALAZiONE CONFERMATA D! PREDAZÍONE Dl PESCE PORCO OXYNOTUS CENTRINA (LINNAEUS, 1758) SU CAPSULE OVARíCHE DI GATTUCCI MINORI SCYLIORHINUS CANICULA (LINNAEUS, 1758) IN ACQUE MEDITERRANEE SINTESI L'esame del contenuto stomacale dl due maschi di pesce porco Oxynotus centrina (Linnaeus, 1758) catturati davanti al litorale di Barcellona nel novembre 2000 e nelgennaio 2001, ha rilevato la presenza di sacchi vitellini ed embrioni appartenentl alia specie dei gattucci minorI Scyliorhinus canícula (Linnaeus, 1758). Per quanto è noto, si traita délia prima segnalazione confermata dt predazione su capsule ovariche di gattucci minorI In acque mediterra-nee. Parole chiave: Oxynotus centrina, Scyliorhinus canicula, predazione, capsula ovarica, embrioni, Mare Mediterráneo 23 ANNALES • Ser. hist. rial. 11 - 2001 • 1 (23) Joan BARRULL & Isabel MATE: fSRST CONFIRMED RECORD OF ANGULAR ROUCHSHARK OXYNOTUS CENTRINA {LINNAEUS, I7S8) ..., 23-28 INTRODUCTION Records of predation on elasmobranch eggs are relatively rare (Cox & Koob, 1993). in this report we discuss the first confirmed record of elasmobranch predation on embryos of an oviparous shark in Mediterranean waters. MATERIAL AND METHODS Two angular roughshark Oxynotus centrina (Linnaeus, 1758) male individuals (Figs. 1, 2) were caught in Catalonia's continental slope waters on November 10th 2000 and January 2nd 2001 by the fishing vessel "Maireta II" based in the port of Barcelona (Spain). The specimens were caught using a trawler net at a depth of 192 m in the fishing ground know as "La Serola", at a geographical position of 41°12' N, 2°28' E (Fig 3). The specimens were identified according to Compagno (1984a). They were deposited at the Ichtbyological Collection of the Zoology Museum of Barcelona, with catalogue numbers MZB-2000-1035 and MZB-2001-0006. The roughshark were examined for parasites. Stomachs were dissected and the contents identified. The reproductive tracts of individuals were examined to determine maturity in agreement with Moreno & Hoyos (1982). RESULTS AND DISCUSSION The two angular roughshark O. centrina male individuals measured both 555 mm total length. In table 1 the main morphometric data of specimens are presented following Compagno (1984a). Both were immature, and Fig. 1: Angular roughshark Oxynotus centrina caught on November 10,b 2000 in coastal wafers off Barcelona. (Photo: f. Barrull & L Mate) SL 1: Morski prašič Oxynotus centrina, ujet 10. novembra 2000 nedaleč od Barcelone. (Foto: /. Barrull & /. Mate) no internal or external parasites were found. The examination of one of the angular roughshark's stomach content revealed only fragments of ten yolk sacks and one 34 mm (total length) embryo (Fig. 4). The embryo, which had an external yolk sack, was determined to belong to the small-spotted catshark Scyliorhinus canícula, which was in agreement with the illustrations and morphological descriptions provided in Compagno (1984b), Moreno (1995) and Van Grevelynghe et al. (1999). The stomach content of the second shark showed two embryos at a total length of 60 mm from Scyliorhinus canícula (Fig. 5). No egg capsules were found. The egg content might have been sucked up by the angular roughshark. Very little is known about the angular roughshark's diet. It is a solitary animal. However, two specimens are sometimes captured at the same time. Angular rough-shark inhabits mud and sand-bottoms at depths of about 50-725 m (Barrull et al., 1999) and it is thought that its diet consists of poiychaetes and small animals from marine bottom (Compagno, 1984a; Barrull & Mate, 1996). Capapé (1975) points out that in Tunisian waters it feeds on crustaceans. Some species of carnivorous gastropods may drill into and feed on embryos, or developing its own young, in egg cases of some oviparous sharks (Mc Laughlin & O'Cower, 1971; Cox & Koob, 1993). Shark egg cases have been taken from stomachs of teleost (Long, 1996), marine mammals (Morejohn & Baltz, 1970; jones, 1981; Condit & Le Boeuf, 1984; Antonelis et al., 1987; Sinclair, 1994) and at least one species of shark (Grover, 1972). The fact that this is the first confirmed record of elasmobranches predation on shark eggs in Mediterranean waters provokes a special Interest. Firstly because it reveals something new about ■■■ ■ - . Fig. 2: Angular roughshark Oxynotus centrina caught on January 2nd 2001 in coastal waters off Barcelona. (Photo: j. Barrull & /, Mate) SI. 2: Morski prašič Oxynotus centrina, ujet 2. januarja 2001 nedaleč od Barcelone. (Foto: j. Barrull & I. Mate) 24 ANNALES • Ser. hist. nat. ■ 11 • 2001 • 1 (23) joan 8ARRULL & tsabet MATE: FIRST CONFIRMED RECORD OF ANGULAR KOUGHSHARK OXYNOTUS CENTRINA {LINNAEUS, 17.58} ,.., 23-28 "*7 r£2 ' / a' - y * J J Fig. 3: Localization of the specimens of Angular rough-shark Oxynotus centrina in the Barcelona littoral (NW Mediterránea n). SI. 3; lokacija osebkov morskega prašiča Oxynotus centrina v barcelonskem obrežnem pasu (SZ Sredozemsko morje). high fat and protein content, and their accessibility. It is also important to point out that small-spotted catsharks and angular roughsharks have a similar bathymetrical distribution in almost all the continental slope and at different depths (BarruSI et ai, 1999). So, this kind of interaction would not be surprising. It would be worth finding out how this predation could affect the small-spotted catshark population. Angular roughsharks are considered an unusual and not a very prolific shark, due to their year-long reproductive period, with litters between 8 and 23 young (Capape et ai, 1999, 2000), while the small spotted cat shark is considered an abundant and very prolific species. Also with a year reproductive period (with seasonal fluctuations), can produce between 96-115 egg cases each year (Capape, 1977). Considering all these facts, we assume that angular roughshark's predation on the small-spotted catshark's eggs will not threaten its population, it would be necessary, however, to acquire more documentation to adequately analyse this phenomena. The fact that this may be the first accurately documented instance of elasmobranch predation on embryos of an oviparous shark in Mediterranean waters, should warrant the special interest. ACKNOWLEDGEMENTS angular roughshark's diet, and secondly for the consequences that this predation may have on species whose eggs are eaten. The records of shark egg cases in stomachs of marine animals are rare (Cox & Koob, 1993). The question is how often this predation occurs. Small-spotted catshark eggs can be an important nutritional source, due to their Fig. 4: Fragments of yolk sacks and 34 mm small-spotted catshark embryo from the stomach content of the November specimen. {Photo:j. Barrull & I. Mate) SI. 4: Delci rumenjakovih vrečk in 34 mm dolgega zarodka morske mačke iz želodca v novembru ujetega morskega prašiča. (Foto: f. Barrull & I. Mate) We wish to thank Mr. David Albiol for his help in collecting sharks, and Dr. Domenech Lloris for his helpful comments on the manuscript. We also would like to thank Ingrid Benito for translating the article into English, and Tiziano Storai for translating the abstract into Italian. Fig. 5:60 mm small-spotted catshark embryos from the stomach content of the January specimen. (Photo: J. Barrull & I. Mate) Si. 5: 60 mm dolgi zarodki morske mačke iz želodca v januarju ujetega morskega prašiča. (Foto: J. Barrull & I. Mate) 25 ANNAL.ES • Ser. hist. nat. - 11 • 2001 • 1 (23) Joan BARRULL & Isabel MATE: FIRST CONFIRMED RECORD OF ANGULAR ROUGHSMARK OXYNOTUS CENTRINA (LINNAEUS, 1758)..., 23-26 Tab. 1: Proportional dimensions of the two angular roughsharks caught off Barcelona. Tab. 1: Proporcionalne dimenzije dveh morskih prašičev, ujetih v obrežnih vodah Barcelone, MZB-2000-1035 MZB-2001-0006 Sex (M) Sex (M) total length (mm) TL 555 555 precaudal length PRC 79.8 80.2 pre-first dorsal length PD1 19.4 19.1 pre-second dorsal length PD2 58.4 57.9 first dorsal length D1L 25.2 22.9 second dorsal length D2L 14.8 14.9 first dorsal base D18 20.9 18.9 second dorsal base D2B 11.7 10.4 first dorsal inner margin D1I 4.3 4.0 second dorsal inner margin D2I 3.1 4.5 first dorsal height D1H 12.1 12.6 second dorsal height D2H 10.3 10.6 first spine length SI 11.0 13.1 second spine length S2 8.8 7.4 dorsal caudal margin C DM 20.7 20.4 preventral caudal margin CPV 12.1 11.3 terminal caudal lobe CTL 6.5 6.7 prepectoral length PP1 18.6 18.5 pectoral anterior margin P1A 15.5 16.0 pectoral posterior margin P1P 14.4 14.0 pectoral base P1B 5.8 4.9 pectoral inner margin PI! 2.5 4.5 prepelvic length PP2 62.2 60.9 pelvic length P2L 10.1 10.8 pelvic anterior margin P2A 6.7 6.1 clasper outer length CLO 1.1 1.3 clasper inner length CIS 5.9 6.1 mouth width MOW 4.6 4.2 preoral length POR 4.0 5.4 nostril width NOW 2.2 3.4 internarial space JNW 1.1 , 2.5 prenarial length PRN 2.0 3.6 prespiracular length PSP 9.4 9.9 preorbital length PQB 4.3 7.7 eye length EVL 4.3 3.8 eye height EYH 2.1 2.0 intergill length INC 4.0 5.1 first gill slit height GS1 1.3 1.7 fifth gill slit height GS5 1.5 1.5 26 ANNALES • Ser. hist. nat. ■ 11 - 2001 • 1 (23) loan BARRUIL & Ssabe! MATE: FIRST CONFIRMED RECORD OF ANGUIAR ROUGHSHARK OXYNOTU5 CčNTRINA (IINNAEUS, 1750J..., 2V28............................ PRVI POTRJEN! PRIMER OPLENjENEGA JAJČNEGA OVOJA MORSKE MAČKE SCYLIORHINUS CANICULA V TREBUHU MORSKEGA PRAŠIČA OXYNOTUS CENTRINA (LINNAEUS, 1 758) V SREDOZEMSKEM MORJU Joan BARRUIL & Isabel MATE lab. Vertebrats iieccio ictiobgia, Museo Zoobgia, E-08060 Barcelona, Aptat correus 593 E-mail: ji5arruli@pie.xtec.es POVZETEK Podatki o plenjenju jajčec morskih psov in skatov so razmeroma redki. Nekatere vrste mesojedih polžev lahko vrtajo v zarodke (in se hranijo z njimi) ali vzrejajo zarod v kapsulah ovipamih morskih psov. Jajčni ovoji sami pa so bili najdeni v želodcih pravih kostnic, morskih sesalcev in v najmanj eni vrsti živorodnega morskega psa. V tem prispevku avtorja razpravljata o bržkone prvem potrjenem primeru plenjenja zarodkov oviparnega morskega psa v vodah Sredozemskega morja. Dne 10. novembra 2000 in 2. januarja 2001 sta bila z vlečno mrežo ribiške ladje "Maireta II" (z matičnim pristaniščem v Barceloni) ujeta dva 550 mm dolga samca morskega prašiča Oxynotus cen-trina (Linnaeus, 1758) v vodah celinskega pobočja nedaleč od katalonskega obrežja. Ujeta sta bila v globini 192 metrov na ribiški lokaciji, znani kot "La Serola", in sicer 4 V" 12' N, 2°28' E. Oba samca sta bila izročena Zoološkemu muzeju v Barceloni m označena s kataloškima številkama MZB-2000-l035 in MZB-2001 -0006. Pregled želodca enega od morskih prašičev je razkril delce desetih rumenjakovih vrečk in enega zarodka v skupni dolžini 34 mm. Na osnovi primerjav z ilustracijami in morfološkimi opisi Compagna (I984a), Morena (1995) in Van Grevelvngheja et al. (1999) je bilo ugotovljeno, da je zarodek, z zunanjo rumenjakovo vrečko, pripadal morski mački Scyliorhinus canicuia (Linnaeus, 1758). V želodcu drugega morskega prašiča pa sta bila odkrita dva zarodka morske mačke Scy!iorhinus canicuia v skupni dolžini 60 mm. Jajčnih ovojev ni bilo, in prav mogoče je, da je morski prašič jajčno vsebino izsesai. Ta primer bo bržkone pritegnil še nadaljnje zanimanje strokovnjakov, saj je prvi natančno dokumentirani zapis o morskih psih (Elasmobranchii) z uplenjenimi zarodki oviparnega morskega psa v vodah Sredozemskega morja. Ključne besede: Oxynotus centrina, Scyliorhinus canicuia, predatorstvo, jajčni ovoj, zarodki, Sredozemsko morje REFERENCES Ankmelis, G. A., M. S. Lowry, D. P. De Master & C. H. Fiscus (1987): Assessing northern elephant seal feeding by stomach lavage. Marine Mammal Science, 3, 308-322. BarruJI, J. & I. Mate (1996): Els taurons dels Pa ¡'sos Catalans. Barcelona, Pôrtic, 183 pp. BarruJI, }., I. Mate & M. Bueno (1999): Observaciones de tiburones (Chondrichthyes Euselachti) en aguas de Cataluña (Mediterráneo NO), con algunos aspectos generales de su ecología. Scientia gerundensis, 24, 127- 151. Capapé, C (1975): Observations sur le régime alimentarle de 29 Sélaciens pieurotrêmes des côtes tunisiennes. Arch. Inst. Pasteur Tunis, 52(4), 395-414. Capapé, C. (1977): Contribution à la biologie des Scyliorhinidae des côtes tunisiennes. I. Scyliorhinus canícula (Linné, 1758): répartition géographique et bathymétrique, sexualité, reproduction, fécondité. Bull. Off. Natn Pêch. Tunisie, 2(1 -2), 109-140. Capapé, C., A. A. Seek & J. P. Quignard (1999): Observations on the reproductive biology of the angular rough shark, Oxynotus centrina (Oxynotidae). Cybium, 23(3), 259-271. Capapé, C., ). A. Tomasini & J. P. Quignard (2000): Les Elasmobranches Pieurotrêmes de la Côte du Languedoc (France Méridionale): Observations biologiques et démographiques. Vie et Milieu, 50(2), 123-133. Compagno, L. J. V (1984a): FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1. Hex-anchiformes to Lamniformes. FAO Fish. Synop., 125(4), 1-249. Compagno, L. J. V (1984b): FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 2. Car-charhiniformes. FAO Fish. Synop., 125(4), 251-655. Cox, D. L. & T. j. Koob (1993): Prédation on eiasmo-branch eggs. Environmental Biology of Fishes, 38, 117-125. 27 ANNALES - Ser. hist. nat. • 11 • 2001 1 (23) Joan SARRULL & Isabel MATE: FIRST CONFIRMED RECORD OF ANGULAR ROUGHSHARK OXYNOTUS CENTRINA (LINNAEUS, 1758}..., 23-28 Condit, R. & B. J. Le Boeuf (1984): Feeding habits and feeding grounds of the northern elephant seal, journal of Mammalogy, 65, 281-290. Grover, C. A. (1972): Predation on egg-cases of the swell shark, Cephaloscyllium ventriosum. Cope ¡a, 1972, 871-872. Jones, R. E. (1981): Food habits of smaller marine mammals from northern California. Proceedings of the California Academy of Sciences, 42, 409-433. Long, D. J. (1996): First confirmed record of teleost predation on a shark egg case. California Fish and Game, 82(2), 103-104. Mc Laughlin, R. H. & A. K. O'Gower (1971): Life history and underwater studies of a heterodont shark. Ecological monographs, 41, 271-289. Morejohn, G. V. & D. M. Baitz (1970): Contents of the stomach of an elephant seal, journal of Mammalogy, 51, 173-174. Moreno, }. A. (1995): Guía de los tiburones de aguas ibéricas, Atlántico Nororíental y Mediterráneo. Pirámide, Madrid, 310 pp. Moreno, J. A. & A. Hoyos (1982): La reproducción de los tiburones. Quercus, 7, 28-30. Sinclair, E. H. (1994): Prey of juvenile northern elephant seals (Mirounga angustirostris) in the Southern California Bight. Marine Mammals Science, 10, 230-239. Van Grevelynghe, G., A. Diringer & B. Séret (1999): Tous les requins du monde. Ed. Delachaux et Niestié, Lausanne, 336 pp. 28 ANNALES • Ser. hist. nat. • 11 - 2001 • 1 (23) original scientific paper UDC 574.5:597(497.4) received: 3.4.2001 MARBLE TROUT (SALMO MARMORATUS) AND BULLHEAD (COTTUS GOBIO) IN TWO SLOVENE RIVERS (ADRIATIC SEA BASIN) Suzana ŠUMER FiBRA d.o.o. Ljubljana, Si-1370 Logatec, Cesta 5. maja 3E E-mail: suzana.sumer@ebra.5i Srečko L FINER Croatian Natural History Museum, HR-10000 Zagreb, Demetrova 1 Meta POVŽ Fisheries Research institute Ljubljana, Si-1000 Ljubljana, Župančičeva 9 ABSTRACT Population density, growth and condition of marble trout Salmo marmoratus Cuvier, 1329 in the river TrebuScica and bullhead Cottus gobio Linnaeus, 1758 in the river Bela were estimated. Ageing of bullhead could not be established due to its lack of scales. In the TrebuSCica, marble trout is a dominant species, with high density of 955 spedmens/ha and low biomass of 26 kg/ha. The youngest marble trout specimens (age groups 0 and I) constitute 81% of the entire estimated population. The mean condition factor was low (0.83) with the highest growth rate of 6-15 cm long trout (1.56 and 0.86, respectively). For the conservation of this species, no further introduction of brown and rainbow trout is recommended and angling restrictions of marble trout applies. In the river Bela, about 86% (specimens/ha) and 35% (kg/ha) of the total fish population are represented by bullheads. Bullheads' density of 11,708 specimens/ha is the first record of such high density in Slovenia. The mean condition factor of bullhead was rather high (1.01). Key words: marble trout, bullhead, population density, age, growth, condition, Slovenia TROTA MARMORATA (SALMO MARMORATUS) £ SCAZZONE (COTTUS GOBIO) IN DUE FlUMl IN SLOVENIA (BACJNO ADRIATICO) S1NTES1 L'articolo riporta i dati inerenti la densita di popolazione, la crescita e la condizione delta trota marmorata (Salmo marmoratus Cuvier, 1829) nel fiume TrebuSüca e dello scazzone (Cottus gobio Linnaeus, 1758) nel fiume Bela. Per la trota marmorata sono state stud/ate anche le classi d'eta. La trota marmorata é la specie dominante nel TrebuScica, con una densitá molto alta pari a 955 individui per ha ed un basso valore di biomassa, 26 kg per ha. Gli individui piú giovani di questa specie (classi d'eta 0 e J) rappresentano l'81% dell'intera popolazione stimata. L'Índice di condizione medio é risultato basso, pari alio 0.83, con il piu alto tasso di crescita delle trote di 6-15 cm (rispettivamente 1.56 e 0.86). Per la tutela di questa specie, gli autori raccomandano di evitare ulteriori introduzioni di esemplari di trota farío e trota iridea, nonché di applicare restrizioni alia pesca della trota marmorata. Nel fiume Bela lo scazzone rappresenta I'86% (esemplari per ha) ed i 135% (kg per ha) dell'intera popolazione ittica. La densita dello scazzone, pari a 11708 individui per ha, corrisponde alia densita piú alta mal segnalata in Slovenia. Parole chiave: trota marmorata, scazzone, densita di popolazione, eta, crescita, condizione, Slovenia 29 ANNALES • Ser. hist nat. 11 • 2001 1 (23) Suitana SUMEf! el a<.;MARBL£ TROUT (SALMO MARMORA OtfMND BULLHEAD (COITUS COBIO) IN TWO SLOVENE RIVERS (ADRIATIC SEA BASIN), 29-34 INTRODUCTION The marble trout (Salmo marmoratus Cuvier, 1829) is the second largest European, exclusively freshwater salmonid species, it inhabits fast running streams with gravel bottom, iow summer water temperature and high dissolved oxygen content. Marble trout is endemic to the Adriatic Sea basin, listed in Annex M at "Council on the Conservation of Natural Habitats and of Wild Fauna and Flora" (Council Directive 92/43/EEC). in the Red Data List of the freshwater fish and lampreys of Slovenia (Pov2, 1996), the species is listed as endangered and it is protected by the National and Regional laws. The marble trout has restricted geographical distribution in the basin of the Po in northern Italy and in the Adriatic basins of the former Yugoslavia and Albania (Crivellt et a!., 2000). The bullhead (Cottus gobio Linnaeus, 1758.) is a small benthic fish living in clear and well-oxygen a ted waters, inside the saimonid zone. Bullhead, too, is threatened by water pollution and stream regulation, and the species is listed in the Slovenian Red Data List (Pov2, 1996) as vulnerable. It has been protected by the "Decree of Protection of Endangered Animal Species" (Official Journal R Slovenia No. 57/1993). Data presented in this paper are part of a complex ichthyological investigation, commissioned and financed by the manager of the freshwater fish populations in these rivers - the Fishery Society of Tolmin. The aim of this investigation was to asses, on the basis of certain physical, chemical and biological features, the ecological condition of the streams and to implement the proposals for further fishery management. The field-work was conducted in September 1998 and March 1999, but due to the prolonged rainy period and devastating floods in November 1998, only the 1998 data are presented herewith. This work was read at the "International Symposium on Freshwater Fish Conservation: Options for the Future" held in Albufeira in Portugal (Sumer etal., 2000). Data presented in this paper are the very first on the marble trout and bullhead populations concerning the Bela and Trebuscica rivers. The condition factors of both species and instantaneous growth rates for marbie trout have never been calculated before in this country. MATERIAL AND METHODS Study area The river Bela is a north-western tributary of the river Nadi2a. Only part of the Nadila, with its source in Italy, flows along the Slovenian border area and Joins the river Ter in Italy. The Bela, with its source at 1,140 m a.s.l., is only 6.29 km long and flows into the Nadi2a at an altitude of about 300 m a.s.i. (Fig. 1). Unfortunately, there are no data available on the drainage area, river hydrology, or water quality. The Bela was regulated in 1930. Its upper course has few 1-2 m high artificial weirs. This part is the trout's nursery stream, in its lower 4 km long course angling is practised. The investigation was carried out on the site located about 1 km upstream of the Bela's mouth. The 70 m long net-blocked segment (471 m2) was selected to cover potential habitat types available to the dealt with fish species. The river Trebuscica is a 16.4 km long south-western tributary of the Jdrijca. Its source is at 1,125 m a.s.l. and joins the Idrijca at about 183 m a.s.l. (Fig. 1). its catchment area covers 74 km2. According to the Hydromete-orological Institute of Slovenia (1999 and 2000), the annual water level fluctuated from 0.45 - 0.63 m to the highest .3.27 m. Annual water discharge varied from 0.5 m3/s to 2.7 m3/s with the maximum of 58.7 m:!/s. The upper 6 km of the Trebuscica is a sanctuary area, inhabited by genetically pure marbie trout, followed by 1 km of nursery stream. The lower 9.4 km long course is used for angling. The investigation was carried out on the site some 3.5 km upstream of the mouth. The 150 m long net-blocked segment (2,136 m2) was selected to cover potential habitat types available to the dealt with fish species. Sampling and methods Fish sampling was carried out on September 19, 1998. Fish were progressively captured and removed during three to four passes with DC electrofishing equipment until the last catch reached about 15% of the first catch. Sampled sections were blocked at the upper and lower ends with 6-mm seins. Captured fish were anaesthetised, identified, measured to the nearest mm (TL) and weighed to the nearest g. Ten to twenty scales were removed below the adipose fin and above the lateral line from each marble trout. Scales' annuli were examined at x 20-40 magnification, and annuli were identified following the criteria presented by Ricker (1968). The age of fish was presented as the age groups where age group 0 refers to the first year of life. Ageing of bullhead could not be estimated, as its body is not covered with scales. The Zippin method (Higgins, 1985), where the numbers of fish in successive catches decrease (n1>n2>n3 etc.), and the Carle-Strub method, where n1>n2256 mm, cobbles: 64-256 mm, gravel: 2-64 mm, sand: 0.06-2 mm. Legenda: W: povprečna širina (m), D: povprečna globina (cm), Min-Max: najnižje - najvišje vrednosti, veliki kamni >256 mm, večji prodniki: 64-256 mm, prod: 2-64 mm, pesek: 0,06-2 mm. Tab. 2: Fish density (specimens/ha) and biomass (kg/ha) with ± 95% CI (± 95% Confidence interval) in the Bela and Trebuščka rivers. Tab. 2: Gostota (število rib/ha) in biomasa (kg/ha) rib ±95% CI (± 95% interval zaupanja) v Beli in TrebuŠčicl RIVER BELA RIVER TREBUŠČICA Species specimens/ha kg/ha specimens/ha kg/ha S. marmoratus 319 (±8) 7.7 (±1.8) 955 (±77) 25.6 (±1.9) 5. f. m. fario. 43 (±0) 12 (±0) 75 (±0) 4.2 (±0) S. t. m, fario x S. marmoratus 1,940 (±29) 127.8 (±2.9) 585 (±11.5) 18.9 (±0.4) O. my kiss 1,241 (±33) 74.6 (±5) 252(±24) 11.7 (±0.8) Thymallus tbymallus 24 (±5) 2.7 (±0.9) Phoxinus pboxinus 30 (±8) 0.6 (±0) Barbus caninus 20 (±8) 1.1 (±0) C. gobio 11,708 (±1,811) 75.2 (±0) TOTAL 13,619 (±745) 212 (±26) 1,926 (±58) 64.4 (±2.6) Tab. 3: Mean body length, weight, condition factor, and growth rate of Salmo marmoratus from the river Trebuščka and of Cottus gobio from the river Bela. Tab. 3: Povprečna telesna dolžina, teža, indeks kondicije in stopnja rasti soške postrvi Salmo marmoratus v reki Trebuščici in kaplja Cottus gobio v reki Beli. River Trebuščica - S. marmoratus River Bela -C. gobio Parameters Age group (years) 0 1 2 3 4 7 n 59 91 24 2 7 1 400 L 8(±1.24) 1 3.3(±1.06) 17.4 (±1.48) 21-8 (±1.06) 28 (±0.58) 41 9.1 (±2.17) L-range 6-11.5 11.5-15 15.5-19.8 21-22.5 27-28.5 4.5-13.5 W 4.3 (±2.43) 20.3 (±4.93) 47.8 (±13.12) 85 (±18.38) 189.4 (±15.95) 700 8.9 (±5.38) W-range 1.8-14 10-32 30-70 72-98 160-206 0.8-24 K 0.78 (±0.15) 0.85 (±0.07) 0.89 (±0.07) 0.82 (±0.06) 0.86 (±0.04) 1.02 1.01 (±0.13) K-range 0,78-1.1 0.66-1.04 0.76-0.99 0.78-0.86 0.81-0.92 0.58-1.27 G - 1.56 0.86 - - Legend: n = number of fish caught, L = mean total length (cm) ±SD (standard deviation), W = mean weight (g) ±SD, K = mean condition factor ±SD, G = instantaneous growth rate of weight. Legenda: n - število ujetih rib, L = povprečna totalna dolžina (cm) ±SD (standardna deviacija), W = povprečna teža (g) ±SD, K ~ povprečni indeks kondicije ±SD, G = trenutna stopnja rasti v teži. 32 ANNALES Ser. hist nat. 11 2001 1 (23) Suzana ŠUMER e< 3I.: MARBLE TROUT ISALMO MARMORA TUS) AND BULLHEAD (COUUS COBIOi IN TWO SLOVENE RIVERS (ADRIATIC SEA BASN)' According to Gaudin & Caillere (1990), C. gobio prefers shallow waters and slow to moderate current velocities, shaded areas and scarce emergent vegetation. They cite the results of other authors according to whom, quite on the contrary, the species can be found also in the zones where velocity is high. Its presence is dependent on substrate, the granulometry characterized by enough coarse elements. The low banks of the Bela offer no overhanging vegetation and therefore no shaded areas. The river bed microhabitats had patches of algae, and occasionally Fontinalis sp. appeared. The number of caught bullheads was nearly the same along the entire sampling location, regardless of riffles and pools. According to Gaudin & Caillere (1990), C. gobio is indifferent to water depth (up to 6-9 m) but prefers coarse bottom material that gives it shelter. The Bela bottom materia) consists of rubbles and boulders as the main fish cover areas. The length of the specimens (Tab. 3) was inside the length intervals cited by Oliva ef a/. (1968), Ladiges & Vogt (1979) and Terofal (1996). The mean condition bullheads' factor was rather high 1.01. According to the high population density and the estimated condition factor it appears that the Bela holds favourable environmental conditions for this species. The river Trebuščka In general, the lower course of the Trebuščica is wider than the Bela, characterized by more fluctuating water depth and stream width and less diverse bottom substrate (Tab. 1). Twenty different macro invertebrates taxa were identified. Their low biomass (6 kg/ha) is among the lowest benthic biomasses recorded in the streams of the Adriatic Sea basin (with regard to the September sampling). Its water quality is class (betamesosaprobic). Surrounding areas are free of industry, but with more inhabitants, villages and arable land. In the Trebuščica, too, all determined chemical concentrations were bellow regulated concentrations for unpolluted waters (Zupan eta!., 1996). Six fish species and a hybrid (S. marmoratus x S. trutta m. fario) of the families Salmonidae, Cyprinidae and Thymallidae inhabit the Trebuščica. 5. marmoratus makes 49% of the TrebuScica's total estimated population density and 40% of its total biomass. Its population density is among the highest in the Slovenian Adriatic Sea basin streams (Tab. 2). The estimated biomass was low due to high abundance (81%) of young fish (age groups 0 and 1). There were only few sexually mature specimens of age groups 3 and 4. In comparison with other salmonids, the condition factor of the marble trout was the lowest, while the growth rate of 6-15 cm long specimens was the highest (Tab. 3). The reason for the lowest condition factor may be associated with limited environmental conditions and introduced indigenous fish species occupying available ecological niches in the stream. The relatively high abundance of young fish is due to the fishery management. From 1996 on, marble trout of size 9-15 cm have been intensively stocked. At the same time there is also a possibility of migrations from the upper course of the river, inhabited only with marble trout (sanctuary and nursery stream segments). There are numerous young fish, with very few catchable size adults. In Slovenia, strong decline of this species has been recorded during the last 80 years. It is threatened by a permanent introduction of brown trout (Salmo trutta), water pollution, river regulation and reservoir constructions (Pov2 et a!., 1996). The marble trout is heavily affected by stocked alien Atlantic 5. trutta and Danubian and/or Mediterranean Salmo species, and presently there are only few populations of marble trout that are believed to be unaffected by introgression (Delling et ai, 2000). By the end of the last century, brown trout of different origins have been introduced into geographical area where the marble trout occurs, quickly resulting in hybrid populations (Crivelli et ai, 2000). In the Adriatic basin of Slovenia, the first introductions took place in 1906 (Pov2 et ai, 1996). During the marble trout rehabilitation project, which began in 1993, eight genetically pure populations were discovered in headwater streams in the upper reaches of the Soca river in Slovenia, the TrebuSCica being one of them. As a result of the first phase of this project, the prohibition on the release of Salmo trutta in the Soca watershed became effective in 1996 with the "Curricular for the ban of brown trout stocking in the Adriatic Sea basin, Slovenia" (Ministry of Agriculture, Forestry and Food, March 25^, 1996). Both fivers are rather narrow with low water level (especially the Bela). According to the September data, the amount of food source is quite limited. The latter and the genetic conservation of marble trout were the most important reasons for the recommendation of a suitable management based on no introduction of other fish species and angling restrictions of marble trout. 33 ANNALES • Ser. hist. nat. 11 • 2001 1 (23) Suzana ŠUMER crtaL-MARBLE TROUT (SALMO MARMORATUS) f\HD fiULLHEAD (COTTUS GOBIO) IN TWO SIOVENE RIVERS (ADRIATIC SFA BAS iN), 29-34 SOŠKA POSTRV {SALMO MARMORATUS) IN KAPELJ {COTTUS GOBIO) V DVEH SLOVENSKIH REKAH SEVERNOJADRANSKEGA POVODJA Suzana ŠUMER EBRA d.o.o. Ljubljana, Si-1370 Logatec, Cesta 5. maja 3E, E-rnail: suzana.sumer@ebra.si Srečko IEINER Hrvatski pnrodosbvrcj muzej, HR-10000 Zagreb, Demetrova 1 Meta POVŽ Zavod za ribištvo, $¡-1000 Ljubljana, Župančičeva 9 POVZETEK Avtorji pričujočega raziskovalnega dela so merili populacijsko gostoto, stopnjo rasti in kondicijsko stanje soške postrvi Salmo nnarmoratus Cuvier, 1829 v reki Trebuščici ter kaplja Cottus gobio Linnaeus, 1758 v reki Beli. Starostno strukturo so ugotavljali le pri soški posrtvi. Soška postrv je v Trebuščici dominantna vrsta z visoko gostoto 955 osebkov/ha in nizko biomaso 26 kg/ha. Najmlajši osebki soške postrvi (starostna skupina med 0 in 1) sestavljajo 81% celotne ocenjene populacije. Povprečni indeks kondicije je bil nizek (0,83) z visoko stopnjo rasti 6-15 cm dolgih postrvi (1,56 oz. 0,86). Za zaščito avtohtone soške postrvi avtorji odsvetujejo nadaljnje vlaganje amerikank in potočnih postrvi in hkrati vztrajajo pri omejitvah športnega ulova soške postrvi. Kaplji v reki Beli sestavljajo kakih 86% (osebkov/ha) in 35% (kg/ha) celotne ribje populacije. Njihova gostota 11.708 osebkov/ha je najvišja, kar jih je bilo doslej zabeleženih v Sloveniji. Povprečni indeks kondicije kapljev je bil razmeroma visok (1,01). Ključne besede: soška postrv, kapelj, populacijska gostota, starost, stopnja rasti, kondicijsko stanje, Slovenija REFERENCES Allan, J. D. (1995): Stream Ecology. Chapman and Hail, London-Madras, 60 pp. Compagnat, P., F. Vancayseele & A. Rumeau (1994): Indice Biologique Global Normalise I.B.G.N., NF t 90-350, Giude Technique. Grenoble: Cabinet GAY Envi-ronnement, p. 68. Crivelli, A. J, G. Poizat, P. Berrebi, D. Jesenšek & J.-F. Rubin (2000): Conservation Biology applied to Fish: The example of a project for rehabilitating the marble trout (Salmomarmoratus)in Slovenia. Cybium, 24(3), 211-230. Delling, B., A. }. Crivelli, J.-F. Rubin & P. 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National Museum of Natural Sciences, Madrid, 51 pp. Oiiva, O., S. Hrabe & j. Lac (1968): Stavovce Slovenska I, Ryby, obojlivelniky a plazy. Vydyvytelstvo Slovenskej Akademie Ved, Bratislava, 204 pp. Platts, W. S., W. F. Megahan & G. W. Minshai (1983): Methods for Evaluating Stream, Riparian and Biotic Conditions. General Technical Report INT-138, Ogden, Utah, 50 pp. Povz, M. (1996): The Red Data List of the freshwater lampreys (Cyclostomata) and fish (Pisces) of Slovenia, in: Kirchofer, A. & D. Hefti (eds): Conservation of Endangered Freshwater Fish in Europe, Birkhauser Verlag, Basel, 63-72. Povi, M., D. jesensek, P. Berebi & A. J, Crivelli (1996): The Marble trout Salmo trutta marmoratus, Cuvier 1817 in the Soca River Basin, Slovenia. Le Sambuc, Tour du Valat Publication, p. 65. Ricker, W. E. (1968): Methods for Assessment of Fish Production in Fresh Waters. Blackwell Scientific Publications, Oxford and Edinburgh, 102 pp. Sumer, Sv M. Povz & S. Leiner (2000): Status of Salmo marmoratus Cuv. and Cottus gobio L. in two rivers in Slovenia (Adriatic Sea basin). Symp. on the Freshwater Fish Conservation - options for the future. Abstract book, Portugal, Algarve, p. 43 Terofal, F. (1996): SuSwasser-ftsche. Mosaik Verlag GmgH, Munchen, 204 pp. Velasco, j. C, P. A. Rincon & }. Lobon-Cervia (1990): Age, growth and reproduction of the cyprinid Rutilus lemmingii in the River Huebra, Central Spain. J. Fish Biol., 36, 469-480. Zupan, M., S. Brumen, T. Cegnar, M. Dobnikar, j. Gr-bovk, M. Kolbezen, G. Kosi, C. Krusnik, S. Lapajne & P. Mihorko (1996): Kakovost vode v Sloveniji v letu 1994 (The water quality in Slovenia in the year 1994). Hydrometeorological Institute of Slovenia, Ljubljana, 62 pp. 34 ANNALES • Ser. hist. nat. • 11 • 2001 - 1 (23) original scientific paper UDC 597(262.3-11) received: 15.12.2000 SOME NEW DATA ON XYRiCHTHYS NOVACULA (LINNAEUS, 1 758) AND SPARISOMA (EUSCARUS) CRETENSE(LINNAEUS, 1758) FROM THE EASTERN ADRIATIC Jakov DULČIČ & Armin PALLAORO Institute of Oceanography and Fisheries, HR-21000 Spilt, P.O.BOX 500 ABSTRACT A cleaver wrasse, Xyrichthys novacuia, and a parrotfish, Sparisoma (Euscarus) cretense, were caught near Jelsa (Hvar Island) and the Vrhovnjaci archipelago in September and October 2000, respectively. Two specimens of parrotfish were also recorded by visual census in the Palagruia archipelago. As far as the cleaver wrasse is concerned this is, to our best knowledge, the northernmost record of this particular species in the Adriatic Sea. The main morphometric and meristic data are given for both species. The presented morphometric and meristic data of S. cretense are the first for this species from the Adriatic Sea. Key words: Xyrichthys novacuia, Sparisoma (Euscarus) cretense, Eastern Adriatic NUOVí DATi SU XYRICHTHYS NOVACULA (LINNAEUS, 1758) E SPARISOMA (EUSCARUS) CRETENSE(LiNNAEUS, 1758) NELL'ADRIATICO ORIENTALE SINTESI Xyrichthys novacuia, pesce pettine, e Sparisoma (Euscarus) cretense, pešce pappagallo, sono stati pescad nei pressi di Jelsa (isola di Hvar) e dell'arcipelago di Vrhovnjaci, rispettivamente in setiembre e ottobre 2000. Due esemplari di pesce pappagallo, inoltre, sono stati avvistati con la técnica del censimento visivo nell'arcipelago di Palagruža. In base alie pubhlicazioni disponibiH, il ritrovamento del pesce pettine corrisponde alia segnalazione piü settentríonale di tale specie nel mare Adriático. Nelí'articolo vengono ripodati i principali dati morfometrici e meristici per entrambe le specie. I dati riguardanti S. cretense sono i primi per questa specie nel mare Adriático. Parole chiave: Xyrichthys novacuia, Sparisoma (Euscarus) cretense, Adriático orientale 35 ANNALES • Ser. hist. nat. 11 • 2001 • 1 (23) lakov OULČIČ & Armin PALIA ORO: SOME NEW DATA ON XYRICHTHYS NOVACULA (UNNA f US, 17SS!..., 35-40 INTRODUCTION Some 41 I fish species and subspecies (Cyclostomaia not included) have been observed in the Adriatic Sea (DulCic:, 2000), and this number can so far be regarded as correct and complete for several reasons. Of this number, the very rare and rare fishes make up almost a quarter (96; 23.4%). Two species, cleaver wrasse Xyrichthys novacula (Linnaeus, 1758) and parrotfish Sparisoma (Euscarus) defense (Linnaeus, 1758), belong to the very rare species in the Adriatic Sea (Pallaoro & Jardas, 1996). The records on biology and ecology of these two species in the Adriatic Sea are scarce in literature. Some data existed on X. novacula (Onofri, 1977, 1982, 1987, 1997) and S. crelerise (Morovic, 1979), but most of them are of general character. The main goal of this paper is to present some new data (morphometric and meristic characteristics, northernmost record) on these two species from the Adriatic Sea. VOON,Í*X v V7S ÍÍ7-W.; st f eu S3 nMtwí Qi Weight (W) (in g) 85.47 238.76 Morphometric characters Total length (Lt) 1 8.53 25.33 Standard length (Ls) 16.02 22.16 Head length (Lc) 4.41 5.71 Predorsal length (Lpd) 3.09 6.18 Preanal length (Lpa) 7.47 12.82 Prepectoral length (Lpp) 4.05 5.56 Preventral length (Lpv) 4.02 6.35 Base length D (Ld) 10.44 11.58 Base length A (La) 6.52 4.87 Pectoral length (Lp) 3.32 4.47 Ventral length (Lv) 2.55 3.61 Caudal length (Lc) 3.04 4.96 Max. body height (Tmax) 5.35 6.77 Min. body height (Tmin) 2.07 2.68 Eye diameter (O) 0.71 1.02 interorbita! length (lo) 0.72 1.49 Preorbital length (Po) 1.80 2.03 Postorbitai length (Olo) 1.90 2.66 Meristic characters Dorsal fin (D) IX+12 IX+9 Anal fin (A) 111+12 111+9 Ventral fins (V) S+5 1+5 Pectoral fins (P) 12 12 Caudal fin (C) 1V+12-HV IV+12+IV Linea lateralis (LI) 27 23 37 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) lakov DULČIČ & Armin PALIAORO: SOME NEW DATA ON XYRICHTHYS NOVACULA (LINNAEUS, 1758)..., 35-40 Fig. 2a: Xyrichthys novacula, 9/ 1^.5 cm (Photo: J. Dulčič & A. Pallaoro) SI. 2a: Xyrichthys novacula, 18,5 cm. (Foto: J. Dulčič & A. Pallaoro) Fig. 2c: Sparisoma cretense, males observed by visual census at Palagruža Island. (Photo: B. Furlan) SI. 2c: Sparisoma cretense, samec, opažen med potapljanjem ob otoku Palagruža. (Foto: B. Furlan) S. cretense was found in the sea from the northern to the southern part of the Adriatic (Tab. 2), although it clearly prefers its southern part (Jardas, 1996). Kolomba-tovid (1900, 1904) reported how the first specimen caught in the Adriatic Sea was found at the fish market Fig. 2b: Sparisoma cretense, 25.3 cm, specimen caught near Jelsa, island Hvar. (Photo: j. Dulčič & A. Pallaoro) SI. 2b: Sparisoma cretense, 25,3 cm, osebek ujet v bližini Jelše, otok Hvar. (Foto: J. Dulčič & A. Pallaoro) in Dubrovnik (Southern Adriatic); it was described by Baldo Kosič (famous ichthyologist at that time). The same author reported on two specimens, caught by Gr-gur Bučič (famous naturalist and meteorologist of that time) near the town of Hvar in 1903 (Tab. 2). 38 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Jakov DULČIČ & Atmin PALLAORO: SOME NEW DATA ON XYRICHTHYS NOVACULA (LINNAEUS, 1758).... 35-40 Tab. 2: Records of cleaver wrasse and parrotflsh in the Eastern Adriatic. Tab. 2: Podatki o pojavljanju ustnače Xyricythys nova-cula in papagajevke Sparisoma cretense v vzhodnem Jadranu. In the Mediterranean Sea, S. cretense is commonly distributed In the Eastern Basin and along the Northern African coasts (Bini, 1968; Papaconstantinou, 1992), whereas in the Western Basin it was only recorded off Marseilles, Nice, Valencia (Lozano Rey, 1952) and Balearic Islands (Riera et at., 1995). The parrotfish is quite common along the southern coasts of Italy (Tortonese, 1975), conversely few records were collected along the northern ones. Bini (1968) reports the catch of a single specimen in the waters of Venice (Northern Adriatic Sea), while Bianchi and Morri (1994) recently pointed out its occurrence along the island of Giglio (Northern Tyrrhenian). The species is also found in the waters from Portugal and the Azores southwards to Senegal (Quignard & Pras, 1986). 5. cretense reaches a maximum total length (TL) of 50 cm (commonly from 10 to 30 cm TL) and shows a marked sexual dichroma* tism. Two males from PalagruZa and one from the Vrhovnjaci archipelago were found on rocky substrates with photophlle macroalgae characterised by medium rigidity and gentle slope. Rocky and sandy bottoms with seagrass patches are the preferred habitats of this species (Tortonese, 1975; Jardas, 1996). The parrotfish was mostly observed at relative shallow stands, lower than 12 m depth, except for one small-sized specimen, with a peculiar livery, recorded on Posidonia oceanica. Therefore, this species seemed to prefer shallow rocky substrates with photophile macroalgae, as observed in this study and along the coast of Ustica Island (Vacchi et a/., 1999). Other authors (Bini, 1968; Tortonese, 1975) also reported on the occurrence of this species on soft bottoms. The occurrence of 5. cretense along Ustica Island (36 nautical miles off the northern coast of Sicily) is consistent with the northern extension of the biogeographical range of these thermophilous species, as a result of a warming up of the Mediterranean waters (see Francour et a!., 1994; Riera et al., 1995). In particular, the capture of 5. cretense in the Southern and Central Adriatic during this year occurred more and more frequently, suggesting an increase in the population density, which has been confirmed by the findings of relatively large number of specimens (by visual census) around the islands of KorCula (southern coast) and Mljet (southern coast) (MuSin, Onofri & MiliSid, pers. comm.). The northernmost record of the cleaver wrasse could also support the statement about the southern thermophilous species moving northwards in the last decade in the Adriatic Sea, which could be related to the changes in climate and/or oceanographical conditions (DulCitf et al., 1999). The status of the cleaver wrasse and parrotfish needs to be evaluated on a continuous basis as it is becoming increasingly apparent that uncommon species, and particularly those on the edge of their distribution, can be essential indicators of environmental changes (Swabby & Potts, 1990). Species Area/Date/Number Source Xyrichthys novacula First record, Gulf of Trieste (??) Stossich (1880) Pelješac Channel, western coast of the town of Korčula, 27.08.1977, one specimen ($) Onofri (1977) Pelješac Channel, western coast of the town of Korčula, several days after 27.08.1977, three specimens (9) Onofri (1982) Pelješac Channel, western coast of the town of Korčula, 1983, several specimens Onofri (1997) Isle of Knežič, Lumbarda, Korčula Island, Pelješac Channel, 1988, one specimen Pallaoro & Jardas (1996) Sparisoma cretense First record, Dubrovnik Kolombatovič (1900, 1904) The town of Hvar, Hvar Island, 1903, two specimens Kolombatovič (1900, 1904) Venice (Italy), one specimen Ninni (1924), Bini (1968) Komiža, Vis Island, 07.08.1925, two specimens Pallaoro & Jardas (1996) Biševo Island, 06.07.1962, one specimen Morovič (1979) Ščedro Island, 18.08.1965, one specimen Morovič (1979) 39 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Jakov DULČIČ & Armln PALLAORO: SOME NEW DATA ON XYRICHTHYS NOVACULA {LINNAEUS, 1/58)..., 35-40 NEKAj NOV!H PODATKOV O VRSTAH XYRICHTHYS NOVACULA (LINNAEUS, 1758) IN SPARISOMA (EUSCARUS) CRETENSE IZ VZHODNEGA JADRANA Jakov DULČIČ& Armin PALLAORO institut za oceanografijo in ribištvo, HR-21000 Split, P.P. 500 POVZETEK Septembra leta 2000 je bila v bližini jelše (otok Hvar) ujeta samica ustnače Xyrichthys novacuia, oktobra istega leta pa na območju otočja Vrbovnjaci samec papagajevke Sparisoma (Euscarus) cretense. Dva samca papagajevke sta bila opažena tudi med potapljanjem na območju otoka Palagruže avgusta meseca istega leta. Pojavljanje ustnače Xyrichthys novacuia je po najinih podatkih najsevernejše za to vrsto v Jadranu. V članku so podani vsi glavni morfo-metrični in meristični podatki za obe vrsti, ki so k primeru papagajevke hkrati tudi prvi podatki za Jadran nasploh. Odkritja papagajevke in ustnače sevemeje od območja, kjer je bila ta vrsta zabeležena do zdaj, bi zaradi dejstva, da sta obe vrsti v Jadranu redki in toploljubni, lahko povezali s spremembami v oceanografskih značilnostih Jadrana. Ključne besede: Xriychthys novacuia, Sparisoma (Euscarus) cretense, vzhodni Jadran REFERENCES Bini, G. (1968): Atlante det Pešci delle Coste itaiiane. Vols. V, VI. Mondo Somerso, Milano. Bianchi, C. N. & C. Morri (1994): Southern species in the Ligurian Sea (northern Mediterranean). Boll. 1st. Mus. Biol. Univ. Genova, 58-59, 181-197. Dulčič, J. (2000): Ugroženost i zaštita jadranske ihtio- faune. Hrvatska vodoprivreda, 92, 47-49. Dulčič, J., B. Grbec & L. Lipej (1999): Information on the Adriatic ichthyofauna-effect of water warming? Acta Adriat, 40 (2), 33-44. Francour, P., C. F. Boudouresque, J. G. Harmelin, M. L. Harmelin-Vivien & J. P. Quignard (1994): Are the Mediterranean Waters becoming Warmer? Information from Biological indicators. Mar. Poll. Bull., 28 (9), 523-526. Jardas, I. (1996): Jadranska ihtiofauna. Školska knjiga, Zagreb, 533 pp. Kolombatovic:, J. (1900): Druge zoologičke vijesti iz Dalmacije, Scarus cretensis. Program Velike Realke, 14, Split. Koiombatovič, j. (1904): Contribuzioni alia fauna dei vertebrati della Dalmazia. Pešci. Glasnik Hrv. Nar. Dr. Zagreb, 13, 4-6. Lozano Rey, L. (1952): Peces fisoclistos, subseries Torácicos. Segunda parte, ordenes Labriformes y Escom-briformes. Mem. R. Acad. Cieñe. Exact. Fis. Nat. Madrid, ser. Cieñe. Nat., 14, 1-613. Morovi7 0 6.0 5.0^ (1.0 3.0 2.0 1.0 0.0 Fig. 3: Temporal and vertical distributions of nitrate concentrations at stations CZ and F during 1992 and 1993 (* the different shades of black in the figure correspond to the different concentrations). Si. 3: Časovna in globinska porazdelitev koncentracij nitrata na postajah CZ in F v letu 1992 in 1993 (* različna intenziteta Črne barve na sliki ustreza različnim koncentracijam). CZ F FAJADDfAJAOD months (1992-1993) Ammonium (fiM) 5.0 4.0 3,0 2,0 1.0 0,0 Fig. 4: Temporal and vertical distributions of ammonium concentrations at stations CZ and F during 1992 and 1993. (* see comment at figure 3). Si. 4: Časovna in globinska razporeditev koncentracij amonija na postajah CZ in F v letih 1992 in 1993. (* glej razlago pri sliki 3). 56 ANNALES • Ser. hist. nat. • 11 - 2001 1 (23) Valeniina TURK ef al.: SEASONAL VARIABILITY IN PHYTOPLANKTON AND BACTURIOPLANKTON DISTRIBUTION ..... 53-64 Chf a H at station F (Fig. 5). Among eucaryotic plankton, diatoms dominated winter-early spring bloom 1992 (Fig. 6), with a peak of 8.33 x 106 cells H and 3.49 x 1G6 cells H at stations CZ and F, respectively. The stratification of water column developed later in May, when low concentrations of phytopfankton bio-mass were measured throughout the water column (0.49-0.94 pg Chi a H) at both stations and in both years. Microflageilates and cyanobacteria reached peak abundance in August-September in both years. In 1993, additional seasonal peaks of cyanobacteria were observed in May, followed by a decrease in june and july (Fig. 7a), and in November. The numbers varied between 0.85 x 107 7.55 x 10? cells h1 at station CZ and from 0.59 x 107 to 5.80 x 10? cells H at station F, and higher abundance was recorded in 1993. An additional input of nutrients in October-November along with autumn cooling, stronger winds, and mixing of the water column provoked a second diatom bloom. This winter-spring diatom bloom was more evident at station CZ in 1992 (phytopiankton biomass up to 2.28 Chi a pg H) but less obvious i n 1993. In general, the yearly mean and maximum concentrations of inorganic nutrients (except phosphate) and the chlorophyll biomass were lower at station F in comparison to concentrations at station CZ (Tab. 1). Annual distribution of heterotrophic pelagic bacteria and nanofiageHates In 1992, the annual dynamic of heterotrophic bacterial abundance showed two peaks, one in January and the other in mid-September, in comparison to consistent increase of bacterial abundance in 1993 up to the October maximum (Fig. 7b). In the winter period, the bacterial abundance declined sharply in February, when seawater reached the lowest temperature. Bacterial numbers varied between 0.24 x 108 and 1.72 x 109 cells H at station F and 0.48 x 108 and 1.89 x 109 cells I"1 at station CZ. Throughout the water column, heterotrophic bacteria were uniformly distributed in the winter-spring period. During the summer, the high concentrations were recorded in the upper 10 meters, while in September and October the highest values were found above the bottom. High bacterial abundance above the bottom co-occurred with a peak of ammonium (r2=0.43, p<0.G01) during the same months. The vertical distribution of heterotrophic bacteria followed similar seasonal pattern at both stations. The yearly maximum concentration was lower at station F in comparison to concentration at station CZ (Tab. 1). On a yearly basis, there was a significant correlation between bacterial abundance and temperature (r*= 0,62, p<0,001), and no correlation between bacterial abundance and Chf a concentration or inorganic nutrients, with exception of ammonium at the bottom level. Minimal bacterial abundance coincided with the end of spring Chi a maximum. Both cyanobacteria and heterotrophic bacteria showed a decline when HNAN dominated. In our samples, nonpigmented HNAN, such as chrysomonads, were the dominating species. The number of HNAN ranged from 0.11 x 10<5 to 6.15 x 10* cells H (Fig. 7c). The maximum concentration was recorded in june and September in 1992, while in the following year abundance was lower (up to 2 x 10s cells I"1), with peaks in May-June, August, and November. Although the composition of the HNAN fauna varied during the study period, some groups remained important throughout the year. The most common forms were flagellates with a length between 1 and 5 ym. The composition of this fauna was dominated by non-pigmented chrysomonads with an average volume of 15.8 pm3. Smaller types, such as a bicoecid flagellate with an average volume between 1 and 3 pm3 , were constantly present, constituting up to 33% of the total counts. FAJAODFA.IAOD fAJAODFAjAOO months (1092-1993) Chlorophyll a (|ig >3.5 3.0 2.5 2.0 1.5 1.0 0,5 0.0 Fig. 5: Temporal and vertica! distribution of phyto~ plankton biomass (Chf a) concentrations at stations CZ and F during 1992 and 1993. (* see comment at figure 3). Si 5: Časovna in globinska razporeditev fitoplankton-ske biomase (Chl a) na postajah CZ in F v letih 1992 in 1993. (* glej razlago pri sliki 3). 57 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Valentina TURK e< al; SEASONAL VARIABILITY IN PHYTO PLANKTON AND B ACTE RIO PLANKTON DISTRIBUTION.....53-64 cz zj v F A O D F A J i months (1992-1993) Phytoplankton (cells s 106 i"1) >1.B 1-5 1.2 0,9 0.6 0.3 0.0 Fig. 6: Temporal and vertical distributions of phyto-plankton abundance at stations CZ and F during 1992 and 1993. (* see comment at figure 3). Si. 6: Časovna in globinska razporeditev fitoplankton-ske abundance na postajah CZ in F v letih 1992 in 1993. (* glej razlago pri sliki 3). Variations in total carbohydrates concentrations (TCHO) Concentrations of total carbohydrates were low (< 150 |jg H) and showed little variability in the bottom layer at both stations and throughout the studied period (Fig. 8). The upper water column exhibited rather different dynamics during the two years of our study: in 1992, very high values were determined in February-March period, which were presumably related to a diatom bloom (Chi a > 7 pg 1-1, abundance > 8 x 10& cells 1-1). There was no comparable bloom in 1993 and TCHO concentrations were low during winter-spring. In 1993, higher values were measured during the summer (July-August). Fractionation of TCHO into high and low molecular fraction was carried out only when values over 200 ^ig H were determined, i.e. in February-March 1992 and July-August 1993. While February-March high concentrations of TCHO were predominantly high molecular weight carbohydrates (ratio HMWiMW > 3), summer high concentrations were characterised by dominance of low molecular weight carbohydrates (HMWIMW < 0.5). DISCUSSION In this study we have followed distribution and abundance of phytoplankton, cyanobacteria and heterotrophic bacteria, simultaneously focusing on the annual cycle at two locations in the Gulf of Trieste (Adriatic Sea). The Gulf of Trieste is a semi-enclosed gulf with the main freshwater inputs from its north-western coast (annual average flow about 150 m-V (Olivotti ef ai, 1986) and peaks over 1000 m^M (Malacic et ai., 1997)). The general circulation pattern is predominantly counter clockwise in the lower layer and of variable size in the surface layer. This circulation can be modulated by prevailing winds (Stravisi, 1983). The physiography of the area includes a limited water exchange and low river inflow, especially during the summer. These conditions may therefore strongly influence the nutrient balance and the succession of plankton organisms. During the course of our study, we encountered two contrasting situations. In 1992, a marked late winter-early spring freshwater input caused intense diatom bloom in the central-western area of the Gulf (station CZ) but reaching also the eastern part (station F). On the other hand, the winter-spring freshwater inflow during 1993 affected the central part of the Gulf of Trieste only slightly and consequently the winter-spring phytoplankton biomass was modest throughout the Gulf. Situation during autumn of both years was quite similar, although the effect of freshwater input seemed to be more marked in 1992. Typically, the upper part of the water column in the centre of the Gulf had higher phytoplankton biomass and diatoms were more important taxa than in the east-em area, reflected also in the prevalence of fucoxantin over other accessory pigments (Terzic et ai., 1998). Such conditions were particularly evident during the winter-spring of 1992 with more abundant freshwater inputs. The higher fluorescence in the deeper water column at station CZ was related to sinking of late winter diatom bloom as indicated by similarity of taxonomic composition between this community and surface one from previous month. Similar, few meters deep fluorescence humps were usually recorded from April to October at varying depths (16 to 23 m) and were much more prominent at station CZ than F. Clearly, the station F was less influenced by freshwater inputs. Oligotrophic conditions in the water column above the pycnocline supported lower phytobiomass and prevalence of cyanobacteria, small eucaryotes and heterotrophic bacteria in both summers throughout the Gulf. The layer below pycnocline was characterised by regenerated and rather high nutrient concentrations. In this layer, phytobiomass was higher than at the surface dominated by large algae (>8 ^im). The period of maximum concentration of ammonium above the bottom coincided with the low oxygen in the overlying water 58 ANNALES • Ser. hist, nat. • 11 - 2001 • 1 (23) Vale turna TURK el a/..-SEASONAL VARIABILITY IN PHYTOPLANKTON AND 8ACTERIOPLANKTON DISTRIBUTION.....53-64 W O 'C u 0 d 1 U 2.0x10 1.5x10 CO s 'C ¡.0xi0'|- O < 6x30 5x10 4x10'' 3x10' 2x104 ix!0 a Bt FOm & F5m A H !0m V F I5m « F tot O CZ On! o CZ5m A CZ lOm O CZ bol J F M A M J JASONDJ F M A M J JASOND months (1992-1993) Fig. 7: Seasonal distribution of cyanobacteria (a), heterotrophic bacteria (b) and heterotrophic nanoflagellates HNAN (c) at different depths a t stations F and CZ in the Gulf of Trieste during 1992 and 1993. SI. 7: Sezonska razporeditev cianobakterij (a), heterotrofnih bakterij (b) in heterotrofnih nanoflagelatov (HNAN) (c) na različnih globinah postaj F in CZ v Tržaškem zalivu v letih 1992 in 1993. 59 ANNALES - Ser. hist. nat. • 11 • 2001 • 1 (23) Valentin« TURK et,1/.: SEASONAL VARIABILITY SN PHYTOPLANKTON AND BACTERIOPLANKTON DISTRIBUTION ....,53-64 (<40% saturation) and high abundance of heterotrophic bacteria. The influence of processes occurring at the interface of marine sediment and overlying water on organic carbon and nitrogen cycling was recorded also in previous years in the shallow Gulf of Trieste (Faganeli, 1983; Turk, 1992; Kemp & Faganeli, 1999). in a course of two years, a marked seasonal variability of marine unicellular cyanobacteria bacteriopfankton community, and HNAN occurred. The abundances were within the range reported from other areas, e.g. Adriatic Sea (Krstulovid & Solid, 1990; Fuks, 1995), English Channel (Linley et a!., 1983), Chesapeake Bay (Malone et ai., 1994), NE coast of USA and South California (Fuhrman & Azam, 1982), Kiel Bight (Meyer-Reil, 1977), Mediterranean Sea (Hagstrom et ai., 1988). On a seasonal scale, the changes in the population size of the entire heterotrophic bacterial community were within a factor of 50%. Seasonality of bacterioplankton species was shown recently by several investigators, using whole-genome probes (Pinhassi & Hagstrom, 2000; Hagstrom et ai., 2000; Fandino ef a!., 2001), The community of heterotrophic bacteria in the sea is dominated by relatively few species undergoing regular, repeatable seasonal successions. Although different bacterial phy-lotypes are dominant in different seasons, single species might persists at high abundance for long periods (up to several weeks) (Rehnstam etal., 1993). Marine bacteria are non-randomly distributed vertically and horizontally as response to concentration gradients in nriicroenvironments. Some of the factors, such as substrate composition, temperature changes and grazing pressure, which influence the growth of bacteria have been subject to control the intra-annual variability. In the Gulf of Trieste, bacterial abundance declined sharply when the lowest temperature was measured in February in both years. Since spring phytoplankton bloom begins while the water is still near its yearly minimum temperature, bacterial growth and activity could be inhibited by low temperature. A positive correlation between temperature and bacterial abundance was established during this study, and had been observed in other aquatic environments, especially during the non-summer seasons (Siah & Ducklow, 1994; Pomeroy & Wiebe, 2001). The higher relative importance of temperature over substrate has been observed when substrate supply was not limiting for bacteria growth (Shiah & Ducklow, 1994). in our measurements, spring phytoplankton bloom was followed by low phosphate and nitrate concentration throughout the water column and by an increase of TCHO concentration, predominantly due to high molecular weight fraction in February-March 1992. The lag in bacterial abundance, which occurred and marked dispersion or accumulation of phytoplankton-derived TCHO, must have taken place before being taken up by bacteria. The ability of bacteria to use carbon-rich substrate has been limited when phosphorous was lacking in our control enrichment experiments (Fajon eta!., 1999). Similar results were found also in other marine waters when accumulation of dissolved organic carbon occurred when bacterial growth was limited by inorganic nutrients (Williams, 1995; Tbingstad & Lignell, 1997). However, interaction of temperature with substrate availability on bacteria! dynamic was evident, a lag phase in biomass increase may reflect the presence of predators - HNAN. Both cyanobacteria and heterotrophic bacteria showed a decline when HNAN dominated. HNAN abundance increased after the spring bloom of diatoms in 1992, and abundance was 3 times higher compared to the following year. The majority of the bacterial biomass could be utilised by protozoa, as shown by previous measurements of HNAN and the recorded grazing on bacteria in our laboratory and in situ experiments (Turk et a!., 1992; Turk & Hagstrom, 1997). The importance of protozoan grazing on bacteria has been stressed in different marine environments (Wikner & Hagstrom, 1991; Solid & Krstulovid, 1994; Solid eta!., 1998). During the summer stratification period, the organisms of microbial food web dominate the plankton population throughout the water column. High concentrations of TCHO, characterised by dominance of low molecular weight carbohydrates {August 1993), co-occurred with high abundance of heterotrophic bacteria, hence, the processes of transformation of organic carbon matter through a 'microbial loop' type of food web might be more important. In the results discussed above we have demonstrated the influence of an initial pulse of freshwater from local river at the station in the centra I-western area of the Gulf on physical, chemical and biological parameters, compared to the other station, which is characterised by predominant influences of more saline/oligotrophic waters of southern origin. In two consecutive years, different pattern of phytoplankton and bacterioplankton seasonal distribution occurred, due to main factors controlling their distribution, such as different pulses of freshwater derived nutrients or control by predators. ACKNOWLEDGEMENTS This work was given a financial support by the Ministry of Science and Technology of the Republic of Slovenia. We thank janez Forte, Franc Kravos, Mira Aviin and Silva Maslo for helping us in field and laboratory work. 60 ANNALES • Ser. hist. nat. • 11 2001 ■ 1 (23) Valentina TURK et a/.: SEASONAL VARIABILITY IN PHYTOPtANKTON AND BACTERIOPLANKTON DISTRIBUTION ,...,53-64 8 (l/Brf) OHOl3 Bo! m O r> _ S mo z . T" * 0 o ■ O B CB • • a - ~> ■ m s" B - < a SJ B b. " B - —j ' C* 0 ■ a. m ■ o SS - BO - o - B O o - o u « ' O B **» ■ OH -i • O B Sj < ■ O H est ».J !..... 1 , !■,,, . . 1 . 1 . ->' 1 I o (l/6ii) OH3X 3 Bot *K> a £> _ 01 C» m o z. T** s o o ° J u> ■ »0 <■ o a -i - B m m <■ B a U. ' a -T' M s o a. Ol tn o a te- O B ti- m m - O M < o b Bt} "t ■ a o - S- so a. (B M. ' ...... I ■ ......... ] —J ss Tf s=> E o T" f a. 0= E o £ a. 9 a O B O. S o> » a o X. ** o B o" o a m ca <• s a -v B - ■•j. B s" B <• a SJ s u.' B T ' « o O. o> O) O B z. O o- CB «0- O B <• o a T ao "5- a s- CJi O B t.,.. 1 i ......... ...... , . -»■ | 8 O (l/Sd) 0H0XS 6o} BO o . S a 01 B O z" C» o" 0 B «■ B O <. o a B - 0 s" B - < • B 0 U. ' IS - -i • pj S o" Ol Ol O H x" O o" O B « «■ O» 0 ■3 - a - X. < ■ on BO u.' ? 'ii-i I < ll,u,l.,„l_,_ ¡■•M 1 ...t,., • 9« a ■a c Bo o ID f a & T3 So S I S i 8 g 8 J R öL s (l/ßi&OHDiaßoi F/g. 8: Seasonal variation in total carbohydrates concentration at different depths at stations CZ (O) and F (•) in the Gulf of Trieste during 1992 and 1993. Si 8: Sezonske spremembe koncentracij celokupnih ogljikovih hidratov na različnih globinah postaj CZ (O) in F (•) v Tržaškem zalivu v letih 1992 in 1993. 61 ANN ALES • Ser. hist, nat. 11 2001 • 1 (23) ValenSir.3 TURK el a/.; SEASONAL. VARIABILITY IN PHYTOPLANKTON AND BACTFRtOPLANKTON DISTRIBUTION.....53-M SEZONSKA RAZPOREDITEV FITOPLANKTONA IN BAKTERIOPLANKTONA V POLZAPRTEM ZALIVU {TRŽAŠKI ZALIV, JADRANSKO MORJE) Valentina TURK, Patncija MOZETIČ & Alenka MALEj Morska biološka postaja, Nacionalni inštitut za biologijo, SI-6330 Piran, Fornače 41 E-mail: turk@nib.si POVZETEK Predstavljena je prostorska in časovna razporeditev hranilnih soli, celokupnih ogljikovodikov, abundance fitoplanktona, cianobakterij, heterotrofnih nanoflagelatov in bakterij na dveh postajah Tržaškega zaliva (severni jadranj v letu 1992 in 1993. Spomladanski vnos hranilno bogate sladke vode povzroči naraščanje števila kremenastih alg predvsem v centralnem delu zaliva, medtem ko so koncentracije klorofila nižje in vrstna sestava fitoplanktona v vzhodnem delu Tržaškega zaliva pod vplivom oligotrofnih vod južnega Jadrana. Ta razlika je bila opazna posebno v zimsko-spornladanskem obdobju leta 1992. Po spomladanskem cvetenju kremenastih alg v letu 1992 so bile izmerjene povišane koncentracije celokupnih ogljikovih hidratov, predvsem visoko-molekulame frakcije. Število heterotrofnih bakterij je v pozno pomladanskem obdobju nizko, kar je verjetno posledica številnih dejavnikov, kot so temperatura, razpoložljiva količina in vrsta substrata ter predacija heterotrofnih nanoflagelatov. Čeprav so potrebni dodatni podatki za zanestlvejše vrednotenje rezultatov raziskave, le-ti kažejo, da dinamiko populacije heterotrofnih bakterij kontrolirajo v veliki meri predatorji, heterotrofni nanofiagelati. Poleti, v obdobju stratificiranega vodnega stolpca, prevladujejo mikroflagelati, enocelične cianobakterije, het-erotrofne bakterij in so pomembni procesi transformacije organske snovi preko "mikrobne prehranjevalne zanke". 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Limnol, Oceanogr., 36, 1313-1324. 64 ANNALES • Ser. hist nat. • 11 • 2001 • 1 (23) original scientific paper UDC 574.5:639.32(262.3) received: 23.5.2001 IMPACTS OF NET CAGE FISH FARM ON SEDIMENTARY BiOGEOCHEMICAL AND MEIOFAUNAL PROPERTIES OF THE GULF OF TRIESTE Nives KOVAČ, Borut VRIŠER & Branko ČERMELj National Institute of Biology, Marine Biological Station, Si-6330 Piran, Fornače 41 E-mail: kovac@rub.si ABSTRACT This study provides basic information about the impacts of a fish farm activity on the Slovenian coastal sea. Samples were collected from the fish farm area (sampling site-SS) and away from the cages (control site-CS). Environmental changes were most evident in benthos showing a long-term impact on meiofauna communities. The meiofauna examination and pore water concentrations of hydrogen sulphide and sulphate indicate the greatest impact directly under the cages. The sedimentation of total suspended matter, particulate organic carbon and total particulate nitrogen in the fish farm region was greater than that at unimpacted area. The lower C/N ratio offish farm suspended matter results from greater supply of proteinaceous material. However, the C/N ratio of sediment under the cages suggests that the system could be in a quasi steady state, where removal processes balance the organic matter loading from the cages. The values of 5UC and ö'sN of fish were similar to those in dry food pellets fed to the sea bass (Dicentrarchus labrax) indicating their primary source of food. Key words: fish farm, 8,5N, 5"C, sediment trap, sediment, meiofauna IMPATTO DELLA PESCSCOLTURA IN GABB1E FLOTTANTI SULLE PROPRIETA BIOCEO-CHIMíCHE DEL SEDIMENTO E SULLA MEIOFAUNA DEL GOLFO DI TRIESTE SINTESI Lo studio fornisce informazioni sull'impatto della pescicollura in acque costiere slovene. i campioni sono stati raccolti nell'area interessata dall'attivitá (sito SS) e fuori da questa (stazione di c.ontrollo C.S). I maggiori cambiamenti ambientali sono stati registrad a livello del benthos, con impatti a lungo termine sulle comunitá meiofaunistiche. i 'analisi della meiofauna e le concentrazioni di idrogeno solforato e di solfato nelle acque interstiziali del sedimento indicano un impatto maggiore direttamente sotto le gabbie. La sedimentazione della materia sospesa totale, del par-ticolato di carbonio orgánico e del particolato di azoto totale é risultata maggiore nell'area interessata dalla pesci-coltura che in quella non affelta. H rninor rapporto C/N della materia sospesa proveniente dalle colture indica un apporto maggiore di materiale protelnaceo. Da! rapporto C/N del sedimento sottostante le gabbie si puó ipotizzare che ¡I sistema sia In uno stato semi-stabile, dove i processi di rímozione bllariciano la materia organica proveniente dalle gabbie. I valorí di S!'C e d'~N nei pesci sono risultatí simili a quelll riscontrati nel manglme secco, fonte primaria di nutrimento per la spigola (Dicentrarchus íabrax). Parole chiave: pescicoitura, álsN, 8"C, trappole per sedimento, sedimento, meiofauna 65 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Nives KOVAČ el al.: IMPACT5 Of NET CAGE FISH FARM ON SEDIMENTARY BIOCEOCHEMSCAl. AND MElOFAUNAt PROPERTIES OF THE GULF OE TRIESTE, 65-74 INTRODUCTION The rapid development of different aquacultures in the world has resulted in several studies directed towards assessment of the environmental impacts of this activity (Hargrave et a!,, 1997). During recent years there has been a significant increase in the number of fish farms established in Mediterranean waters. Below the fish cages, organic matter (OM) originating in fish-food remains and the excreta of the cultured fish often accumulates in the sediment. Enhanced and constant sedimentation of particulate organic waste products results in anoxia, high levels of hydrogen sulphide in sediments and subsequently in alteration of the benthic community and a reduction in bioturbaiion processes. Enhanced aerobic and anaerobic microbial activity in organically rich sediments is resulting in oxygen deple- tion, production of toxic substances such HjS, and low oxidation-reduction potentials are characteristic of anaerobic marine sedimentary environments (Weston, 1990). Hydrogen sulphide produced by sulphate-reducing bacteria, through anaerobic respiration stimulated by available substrate and increasing temperature during early summer, could accumulate within sediments to levels that are toxic to benthic macrofauna and heterotrophic microfauna (Hargrave et a!., 1993). Oxidation of H,S, produced during the anaerobic decomposition of organic matter by sulphate-reducing bacteria, is thought to be the major source of the chemical oxygen demand in marine sediments {Findlay & Watling, 1997). Hydrogen sulphide is also toxic to fish and out-gassing of this from sediments beneath fish cages could have a detrimental effect on fish health (Gowen & Bradbury, 1987). Regardless of the pathway of organic matter Fig. 1:Map of the Gulf of Trieste (northern Adriatic Sea). SI. 1: Lokacija Tržaškega zaliva (severni Jadran). 66 ANNALES • Ser. hist. nat. 11 2001 • 1 (23) Nives KOVAC eta!:. IMPACTS OF NET CAGE FISH FARM ON SEDIMENTARY BSOGEOCHEMICAL AND MEIOFAUNAL PROPERTIES OF THE GULF OF TRIESTE, 65-74 decomposition, if the supply of oxygen is sufficient then hydrogen sulphide will not accumulate within surficial sediments (Findlay & Watling, 1997). The degree of impact depends on many factors such as water current speed and direction, sediment composition, resuspension, benthic fauna and organic loading from fish farm activity (Hargrave ef aL, 1997). Nevertheless, organic output from the fish cages is a serious source of pollution in the affected marine areas. Consequently it is very important to trace organic matter fluxes and estimate their impact on the generally oligotrophic Slovenian marine environment. In order to provide basic information about the impacts of fish farm area in the Slovenian coastal sea and to collect necessary data for the determination of the carrying capacity of the ecosystem and sustainable management of the investigated area, we performed the preliminary study represented by IAEA Research Contract (Environment Programme - UNEP). MATERIAL AND METHODS Study sites The fish cage farm is located in coastal marine waters in Piran Bay - Guif of Trieste (Northern Adriatic) (Fig. 1), The pilot cage facilities were established in 1988. From 1989, sea bass (Dicentrarchus labrax) and sea bream (Sparus aura ta) have been the commercially cultivated species. The bottom depth at the fish farm is 12 to 13 rn. in the fish farm a series of round cages (eight of 8 m in diameter, and eight of 12 m in diameter) have been used for production of fish. The depth of net cages is about 4.5 m. The fish were fed commercial pelted fish food (Marico Start Premium). There is a minor freshwater input from a local stream discharging into the sea about 1.5 km from the fish farm. The water of the Gulf of Trieste is stratified from the spring to the end of summer. The Guff is characterized by large temperature variations (6-26°C in the surficial layer and 6-20°C above the bottom). Surface salinity ranges from 33 to 37.5 PSU and bottom water salinity from 36 to 38.5 PSU. Water circulation in the farm area is sufficient to keep the bottom oxygenated throughout the year. The surficial sediment at the study site is dark grey sandy clayey silt (Ogorelec et ai., 1991) containing up to 20% of sand and up to 35% of clay. With respect to the control site (CS), it is slightly richer in sand and contains less clay, due to the near mouth of the river Dragonja. The carbonate content is above 30%. Ostra-cods, molluscs and foraminifers are the most frequent biogenic components of the sediment. The majority of carbonate minerals is of detrital origin. This is true for quartz, too, and is the third most abundant mineral; its content reaches up to 20%, The clay minerals at the study site are composed of chlorite and mixed structure ¡Uite/montmorillonite. Pyrite observed in the sediment at about 4% indicates reducing conditions and it is normally present in up to 200 |im large framboids few millimetres below the surface. Sampling The samples were collected during a 24 hour long sampling period on 21 and 22 june 2000 at the sampling site (three samplings: morning of first day - sampling i, midnight sampling il and morning of second day - sampling ill) and at the control station (two samplings: morning of first day - sampling I and second day - sampling 111). The sampling site (SS) was located under the cages of sea bass and the control site (CS) at a similar depth was established 1.5 kilometres from the fish farm (Fig- 2). Sediment cores (5 cm in diameter) were collected by SCUBA divers at sampling and control sites. Cores were inserted into the sediment to preserve an intact sedi-ment-water interface and plastic rubber stoppers were used to close the top and bottom of each core. Surficial sediment (0-2 cm) was used for subsequent analyses. For meiofauna analyses three replicate tube core samples (3.2 cm in diameter) were used. The sedimentation rates were measured over a period of 24 hours using moored sediment traps, which were designed to collect 3 samples simultaneously. Cylindrical sediment traps with a diameter of 7 cm and an aspect ratio of 7 were used to collect sinking particles from the cages (positioned below the cages approx. 1 m above the bottom). At the same time, sedimentation rates were also measured at the control site (1.5 km from the influenced area). After collection, three aliquots of homogenized suspension from each cylinder were filtered through precombusted Whatman GF/F glass micro-fibre filters. All samples were freeze-dried for 24 hours and weighed. Dried samples were used for analysis of total suspended matter (TSM), particulate organic carbon (POC), particulate nitrogen (PN) and isotopic composition (nC and l3N). Samples of fish, fish food, fish cage fouling were also collected for stable isotope analysis ("C and ,5N). Different fish tissues (liver, muscle, bone) were carefully dissected and deep frozen. Before isotopic analysis, all samples were freeze-dried and powdered with mortar and pestle. During sampling periods, large quantities of mucous macro aggregates were present in the water column. Hy-perproduction of this mucilaginous material in the northern Adriatic has been known for more than 250 years and recently occurred during the summers of 1988, 1989, 1991, 1997 and this year. These macroaggregates are found in a variety of stages or forms - small floes, macroflocs, stringers, tapes, clouds, creamy surface and gelatinous layers (Stachowitsch eta!., 1990). These mu- 67 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Nives KOVAČ et nI.: IMPACTS OF NET CAGE FISH FARM ON SEDIMENTARY BiOGEOC HEMIC Al AND ME IO FAUN At PROPERTIES OF THE GUI.F OF TRIESTE, 65-74 cous events were previously described by several authors {Degobbis et al., 1995; Herndl, 1992; Mingazzini & Thake, 1995; Kovač etai, 1998; Degobbis, 1999). Analytical methods Total particulate matter was determined gravirnetri-cally. Organic carbon (POQ and total nitrogen (N) content of freeze-dried filters and sediment samples were determined after acid pretreatment with a commercial Carlo Erba 1108 elemental analyser. The water content of the sediment was determined as a weight loss after drying at 80°C until constant weight (approximately 20-30 hrs). Analyses of the "C and 1SN isotopic composition of freeze-dried samples were performed with a Europa 20-20 (Europa Scientific) mass spectrometer. Stable-isotope ratios were expressed in 5 notation as parts per mill {%o) according to the following relationship: where X is "C or ,JN and R is the corresponding ratio "C/,2C or "N/'V Standards for ,3C and ,SN are V-PDB and atmospheric N2 (air), respectively. Fig, 2: Location of sampling (SS) and control (CS) stations in Piran Bay, Gulf of Trieste, Si 2: Lokacija vzorcevalne (SS) in kontrolne (CS) postaje v Piranskem zalivu (TriaSki zaliv). After extraction from the sediment in inert atmosphere, pore waters (0-2 cm depth in sediment, at each sampling point) were used to determine pH and concentration of hydrogen sulphide (H,S) and total carbon dioxide (C02) (Grasshoff, 1983). Concentration of sulphate (SO/) was determined turbidimetrically (Ta-batabai, 1974). Surficial sediment (0-5 cm) containing meiofauna was taken using a core sampler, always with three replicates. Meiofauna was extracted from fixed surficial samples (5% formalin) by sieving and décantation (Wie- ser, 1960), identified as to major taxa and counted. RESULTS AND DISCUSSION Composition and sedimentation of suspended particulate matter Differences in the composition of sedimented particulate matter from sampling (SS) and control (CS) sites are presented in Table 1. During the investigation period, the composition of particulate matter was affected by presence of macroaggregates with high content of carbohydrates and high atomic C/N ratio of 14.7 (mean value of macroaggregates sampled in June 2000). Nevertheless, based on the elemental analyses of the material collected during 24 hours in a trap placed under the fish cages the portion of organic carbon and total nitrogen was higher than that measured at the control site. The particulate matter originating from fish farm was enriched for 43% with organic carbon and about 66% with nitrogen. The higher input of protelnaceous material (organic waste originating in uneaten fish food) was in that case evident also from the lower C/N ratio (7.28, at.) in the sediment trap samples from the sampling station. Tab. 1: Analyses performed in the sedimented particulate matter at sampling (SS) and control (CS) sites. Tab. 1: Analize sedimentirane suspendirane snovi vzor-£evalne (SS) in kontrolne (CS) postaje. Parameter Sediment trap samples (mean values) Sampling site (SS) Control site (CS) Content of organic carbon. (%) 5.50 3.13 Content of total nitrogen (%) 0.90 0.35 C/N ratio (atomic) 7.28 10.60 Sedimentation ratio of total suspended matter (S m2d1) 73.19 36.16 Sedimentation ratio of total particulate nitrogen (g m2d') 0.58 0.13 Sedimentation ratio of particulate organic carbon 1.19 1.44 0.70 1.26 C/N (at.) 9.87 10.77 10.77 11.04 5,3Cro8(%C> -21.87 -21.32 -21.53 -21.58 S1X„(%„) 3.8 3.8 4.2 4.4 70 ANNALES . Ser. hist. nut. 11 • 2001 • 1 (23) Nives KOVAČ et s/.: IMPACTS OF NET CAGE FISH FARM ON SEDIMENTARY BIOGEOCHEMICAL AND MEiOFAUNAL PROPERTIES OF THE GULF OF TRIESTE, 65-74 Tab. 4: Concentrations of sulphate, hydrogen sulphide> total CO, and pH values measured in sediment (SS1, SS2, SS3) under the fish farm and at control site (CS). Tab. 4: Koncentracije sulfata, vodikovega sulfida, celotnega CO, in pH vrednosti izmerjene v pornih vodah sedi-menta (SS1, SS2, SS3) pod ribjimi kletkami in na kontrolni postaji (CS). Parameter SEDIMENT PORE WATER Sampling site (SS) Control site (CS) SSI SS2 SS3 CS S042'(mmoI/L) 19.48 26.92 36.27 22.90 H2S (pmol/L) 0.25 0.55 0.17 0.68 Total C03 (mmoi/L) 2.93 4.40 4.55 2.80 pH 8.17 8.06 7.80 7.97 Tab. 5: Taxa and their mean abundances (No, irtd./10 cm2} determined at the three sampling points (SS1, SS2, SS3) in sediment under the fish farm and at control site (CS). Tab. 5; Glavne skupine meiofaune in njihove srednje abundance (št. oseh./10 cm2), določene na treh vzorčevalnih točkah (SSI, SS2, SS3) sedimenta pod ribjimi kletkami in na kontrolni postaji (CS). MEAN ABUNDANCES (No.ind./10 cm2) TAXA Sampling site (SS) Control site (CS) SSI SS2 SSJ CS Nematoda 374.3 897 11 80.3 1183.6 Harpacticoida 16 35.6 106 255.6 Polychaeta 32.3 34.3 48.3 125 Turbellaria 6.3 17.3 28.3 21.6 Gastropoda 0.6 0 1.3 5 Bivalvia 0 2 6 7 Kjnorhyricha 0 0 0.6 22.3 Acarina 0 0 0 1.3 Hydroidea 0 0.3 2.3 1.6 Ostracoda 1.6 1.6 3.3 6.6 Ascidiacea 0 0 0 44.6 Amphipoda 0.3 0.6 0.3 0.6 Total 431 989 1377 1675 trations of dissolved HjS in the intersticial water of the surficial sediment at all sampling points, almost at the limit of detection. Obviously all dissolved H^S escapes out of the system. This is most probably due to the diffusion of H2S out of the sediment and consequent oxidation in the water column. However, the low sulphate concentration and pH values above 8.1 below the centre of the fish cages might indicate H2S precipitation in a form of pyrite as well (ESen-Yaakov, 1973). Sulphate concentrations decrease from SS3 to SSI indicating strong impact (similar to the results of meio-fauna examination) directly under the centre of cages. Organic matter decomposition and consequently nutrient production in the surficial sediment is vice versa increasing in the opposite direction, with highest nutrient concentrations at SS3. Therefore it is obvious that the for organic carbon/nitrogen varied from 9.87 to 10.77 in sediment under the cages and at the control site was 11.04. Higher C/N ratio of organic matters in the surficial sediment of sampling site probably reflects the preferential degradation of N versus C or/and transportation of organic matter. These results suggest that the system could be in a quasi steady state, where removal processes balance the constant and enhanced organic matter loading from the cages. Sediment water content in surficial sediment (0 to 2 cm layer) varied slightly (51.2% to 56.7%) with no consistent pattern in values between the sampling points under the fish farm. Higher sediment water content (Tab. 3) at the control station (66.4%) most likely reflects the finer grained texture of the sediment. The results presented in Table 4 show low concen- 71 ANNALES • Ser. hist nat. 11 2001 • 1 (23) Nives KOVAČ el ah IMPACTS Of NET CAGE El S H FARM ON SEDIMENTARY 8IOGEOCHEMCAL AND MEIOFAUNAt PROPERTIES OF THE CUI.F OF TRIESTE, 65-74 fish farming impact is spread over at least three times larger area then the cage settlement. The meiofauna revealed differences in abundances and diversity with distance. A list of meiofauna taxa and their abundance at all sites is presented in Table 5. The densities of the total meiofauna were approximately 66% lower at 5S1 point and 33% lower at the SS2 point than at the control site, but the difference was not evident for SS3 sample point. in addition to lower abundances of both total meiofauna and their leading groups (Nematoda, Harpacti-coida, Polycheta, Turbellaria) at the more impacted zone (SS1, SS2), we observed also absence of some typical meiofaunal groups (Gastropoda, Bivalvia, Kino-rhyncha, Hyroidea). According to the data, the meiofauna from the control site reflects typical (normal) summer community of unimpacted area (Vriser, 1997). The same variation in meiofauna could be due to differences in ecological factors (such as particle size distribution of sediment) at sampling and control sites. Few particular studies regarding the fish farming impacts on benthic communities were found in the literature before 1999. Lower abundance and biomass (up to 37% of the normal community) of macrofauna at the fish cages sites are reported by Weston (1990) and Har-grave et al. (1997), though these results are presented in the context of the different methodological and/or ecological aspects. Our results (i. e. a 66% reduction of the total abundance and disappearance of some sensitive groups as Moilusca and Kinorhyncha) are highly consistent with the last published studies (Mazzola et al., 1999, 2000; La Rosa et al., 2000; Mirto et al., 2000) on fish mariculture effects on meiofauna. CONCLUSIONS Environmental changes were most evident in benthos showing a long-term impact of fish farming on meiofauna communities. Settling of unconsumed food and constant deposition of waste and fish feces under and adjacent to fish cages has been found to reduce diversity and abundance of benthic meiofauna. The impact, i.e. impoverishment of meiofauna, was local and most pronounced in the sediment directly below the cages. Pore water concentrations of hydrogen sulphide, sulphate and elemental composition of sediment also indicate the greatest impact directly under the cages. However, despite continuous organic loading on the sediments below the fish cages, the measured concentrations were within variability of the background ievels of the Bay of Piran. The sedimentation of total suspended matter, particulate organic carbon and total particulate nitrogen in the fish farm region was greater than that at the control station because of the higher deposition of organic waste in the form of feces and uneaten food beneath the fish farm. In comparison to the control site, the lower C/N ratio of sedimented suspended matter in the fish farm accounted 7.3 (at.), indicating a greater supply of proteinaceous material. The values of S"C. and S"N of fish were similar to those in dry food pellets fed to sea bass (Dicentrarchus labrax) indicating their primary source of food. The highest values of S"C and 81SN were observed in the sediment trap samples resulting from heterogeneous sedimented material, such as particulate matter, waste food, feces and mucous macroaggregates. Results of this preliminary study suggest that the system could be in a quasi steady state, where removal processes balance the organic matter loading from the cages. Several mechanisms could be responsible for this situation, including site-specific properties such as bottom currents, water exchange and bottom topography, rapid OM decomposition rates, sediment characteristics and bioturbation. Nevertheless, additional analyses concerning the impact on sediment, such as quantification of decomposition of organic matter by benthic flux chamber, observation of bacterial mate and determination of more detailed sediment profiles (biological and chemical parameters) under the fish farm, must be performed in the future. The database from this study provides useful information for the better planning of future investigations of the fish farm impact and for reduction of the organic matter overload in the shallow coastal ecosystem of the northern Adriatic. ACKNOWLEDGEMENT This study is part of the project entitled "Assessment of the impact of fish farming on the oligotrophy environment of the Slovenian coastal sea" (IAEA Research Contract, Environment Programme - UNEP). We thank Tihomir Makovec and Jani Forte for Figures 1, 2 and 3 and for their practical assistance in fieldwork. 72 ANNALES • Ser. hist, nat • 11 - 2001 • 1 (23) Nives KOVAČ etab IMPACTS OF NET CACE FISH FARM ON SEDIMENTARY B!OGEOCHEM!CAL AND MgtOFAUNAL PROPERTIES OF THE GUUr OF TRIESTE, 65-74 VPLIV! GOJENJA RIB NA MEiOFAUNO TER BIOGEOKEMIČNE LASTNOST! SEDIMENTA TRŽAŠKEGA ZALIVA Nives KOVAČ. Borut VRIŠER & Branko ČERMELj Nacionalni inštitut za biologijo. Morska biološka postaja Piran, Si-6330 Piran, FornaCe 41 IE-maii: kovac@rtib.si POVZETEK V območju marikulture se kopiči neporabljena hrana, potrebna za intenzivno gojenje morskih organizmov, presnovni produkti organizmov, kot so feces in različni eksekreti ter različni kemijski dodatki, kot so antibiotiki in protiobrastna zaščitna sredstva. Konstanten in povečan vnos organske snovi posledično vodi do sprememb ekoloških lastnosti obremenjenih območij te vrste, zato smo v okviru te študije opravili preliminarne raziskave območja marikulture rib v Piranskem zalivu. Vzorčevanje je potekalo v okviru 24-urnega terenskega dela (21. in 22. junija 2000) na vzorčevalni postaji v območju gojišča rib ter na kontrolni postaji, locirani zunaj neposrednega vpliva marikulture. Preliminarni rezultati te študije so pokazali največje spremembe v bentoški združbi (spremembe v sestavi populacije meiofaune), ki so odsev dolgotrajnega vpliva marikulture. Osiromašnje meiofaune in višje koncentracije vodikovega sulfida v pornih vodah je bilo najbolj izraženo v sedimentu neposredno pod ribjimi kletkami. V območju gojišča rib smo zabeležili tudi višje vrednost: celotne suspendirane snovi, suspendiranega organskega ogljika in celotnega dušika, kar je verjetno posledica večjega vnosa organske snovi. Nižje vrednosti C/N razmerij suspendirane snovi vzorčevalne postaje pa potrjujejo večji vnos proteinske snovi (odpadne snovi gojenja rib) glede na kontrolno postajo. Izolopska sestava, tj. vrednosti 5UC in S!'N analiziranih gojenih rib> je bila podobna tistim, določenim v hranilnih peletih, s katerimi hranijo ribe, kar kaže, da so le-ti njihov primarni vir prehrane. Rezultati le študije so podlaga in izhodišče za nadaljnje raziskave vplivov marikulture na obalno slovensko morje. Ključne besede: ribje kletke, 5'SN, 5,3C, sedimentacijske pasti, sedimerit, meiofauna REFERENCES Angel, D., P. Krost, D. Zuber & A. Neori (1992): Microbial mats mediate the benthic turnover of organic matter in polluted sediments in the Gulf of Aqaba. Proc. U.S.Israel Workshop on Mariculture and Environment, Elat, Israel, June 1992, 66-73. Ben-Yaakov, S. (1973): pH buffering of pore water of recent anoxic marine sediments. Limnol. Oceanogr., 1, 86-94. Degobbis, D., S. Fonda Umani, P. Franco, A. Maiej, R. Precali & N. Smodlaka (1995): Changes in the northern Adriatic ecosystem and the hypertrophic appearance of gelatinous aggregates. Sci. Tot. Environ., 165, 43-58. Degobbis, D., A. Male) & S. Fonda Umani (1999): The mucilage phenomenon in the northern Adriatic Sea. A critical review of the present scientific hypotheses. Ann. 1st. Super. Sanita, 35, 373-381. Faganeli, J. (1989): Sedimentation of particulate nitrogen and amino acids in shallow coastal waters (Gulf of Trieste, northern Adriatic). Mar. Chem., 26, 67-80. Faganeli, J., N. KovaC, H. Leskovsek & J. Pezdie (1995): Sources and fluxes of particulate organic matter in shallow waters characterized by summer macroaggregate formation. Biogeochemistry, 29, 71-88. Faganeli, J., A. Malej, J. Pezdtf & V. MalaCii (1988): C:N: P ratios and stable C isotopic ratios as indicators of organic matter in the Gulf of Trieste (Northern Adriatic). Oceanol. Acta, 11, 377-382. Findlay, R. H. & L. Watling (1997): Prediction of benthic impact for salmon net-pens based on the balance of benthic oxygen supply and demand. Mar. Ecol. Prog. Ser., 155, 147-157. Gowen, R. ). & N. B. Bradbury (1987): The ecological impact of satmonid farming in coastal waters: a review. Oceanogr. Mar. Biol. Ann. Rev., 25, 563-575. Grasshoff, K. (1983): Methods for sea water analyses. Verlag Chemie, Weinheim, 317 pp. Hargrave, B. T., D. E. Duplisea, E. Pfeiffer & D. J. Wild-ish (1993): Seasonal changes in benthic fluxes of dissolved oxygen and ammonium associated with marine cultured Atlantic salmon. Mar. Ecol. Prog. Ser., 96, 249-257. 73 ANNALES • Ser. hist, nat. • 11 • 2001 • 1 (23) Nives KOVAČ et al.: IMPACTS OF NET CAGE RSH FARM ON SEDIMENTARY 8IOGEOCHEMICA1. AND M El O FAUN At PROPERTIES OE THE GULEOF TRIESTE, 65-74 Hargrave, B, T, G. A. Phillips, L. I. Doucette, M. J. White, T. G. MtIHgan, D. J. Wildish & R. E. Cranston (1997): Assessing benthic impacts of organic enrichment from marine aquacuiture. Water Air Soil Poll, 99, 641-650. Herndl, G. J. (1992): Marine snow in the Northern Adriatic Sea: possible causes and consequences for shallow ecosystem. Mar. Microb. food Web, 6, 149-172. Kovac, N., J. Faganeli, B. Sket & O. Bajt (1998): Characterization of macroaggregates and photodegradation of their water soluble fraction. Org. Geochem, 29, 1623-1634. La Rosa, T., S. Mirto, A. Mazzola & R. Donovaro (2000): Differential responses of benthic microbes and meiofauna to fish-farm disturbance in coastal sediments. Environmental Pollution, 0, 1-8. Mazzola, A., S. Mirto & R. Danovaro (1999): Initial Fish-Farm impact on Meiofaunal Assemblages in Coastal Sediments of the Western Mediterranean. Mar. Poll. Bull, 38, 1126-1133. Mazzola, A., S. Mirto, T. La Rosa, M. Fabiano & R. Danovaro (2000): Fish-farming effects on benthic community structure in coastal sediments: analysis of meiofaunal recovery. ICES). Mar. Sci, 57, 1454-1461. Mingazzini, M. & B. Thake (1995): Summary and conclusions of the workshop on marine mucilages in the Adriatic Sea and elsewhere. Sci. Tot. Envir, 165, 9-14. Mirto, S., T. La Rosa, R. Danovaro & A. Mazzola (2000): Microbial and Meiofaunal Response to Intensive Mussel-Farm Biodeposition in Coastal Sediments of the Western Mediterranean, Mar. Poll. Bull, 40, 244-252. Ogorelec, B., M. Misic & j. Faganeli (1991): Marine geology of the Gulf of Trieste (northern Adriatic): Sedi-mentological aspects. Mar. Geoi, 99, 79-92. Stachowitsch, M., N. Fanuko & M. Richter (1990): Mucus aggregates in the Adriatic sea: An overview of stages and occurrences. P.S.Z.N. I: Mar. Ecoi, 11, 327-350. Tahatabai, M, A, (1974): A rapid method for determination of sulphate in water samples. Environ. Lett, 7, 237-243. Vriser, B, (1997): Seasonal and three-year variability of meiofauna in the Gulf of Trieste (northern Adriatic). Period. Biol, 99, 209-212. Weston, D. P. (1990): Quantitative examination of mac-robenthic community changes along an organic enrichment gradient. Mar. Ecol. Prog. Ser, 61, 233-244. Wieser, W. (1960): Benthic studies in Buzzards Bay II. The meiofauna. Limnol. Oceanogr, 5, 121-137. 74 ANNALES ■ Ser. hist. nat. -11 - 2001 ■ 1 (23) strokovni članek UDK 574.5:591.9(497.4) prejeto: 9.5.2001 MEiOFAVNA ¡ZOLSKE LUKE PRED GRADITVIJO MARINE IN PO NJEJ: PONOVLJENA RAZISKAVA - PRELIMINARNI REZULTATI Borut VRtŠER Nacionalni inštitut za biologijo, Morska biološka postaja, SI-6330 Piran, Fornače 41 IZVLEČEK Članek obravnava strukturne in abundančne značilnosti meiofavne treh vzorčevalnih postaj na širšem področju izolske luke pred graditvijo nove marine (leta 199!) in 8 let pozneje (1999). Preliminarni rezultati ponovljene raziskave za zdaj niso pokazali opaznih biocenotskih sprememb, vsaj ne na ravni glavnih taksonomskih skupin, ki bi jih utegnila povzročiti ekološka motnja sedimentacije skaljenega vodnega sloja med grobimi gradbenimi posegi v morsko okolje. Ključne besede: rneiofavna, Izolska luka, ponovljena raziskava MEIOFAUNA DELL'AREA PORTUALE DI ISOLA PRIMA E DOPO LA COSTRUZiONE DELLA MARINA: STUDIO RIPETUTO - RiSULTATl PRELIMINARI SINTESI L'articolo presenta le caratteristiche strutturall e quantitative della meiofauna in tre stazioni di campionamento nell'area portuale di Isola, prima della costruzione della nuova marina (1991) e 8 anni dopo (1999). Al momento i risultati preliminar! dello studio ripetuto non banno evidenziato eambiamenti di btocenosi, almeno non a ¡¡vello dei maggiorí gruppi tassonomici. Sembra che il maggiore fattore di disturbo ecologico, ¡a sedimentazione del particolato sospeso, non si a stato abbastanza intenso da provocare eambiamenti nievan ti. Parole chrave: meiofauna, area portuale di isola, studio ripetuto 75 ANNAIJES • Ser. hist nat. 11 200Í -1 (23) Borut VRIŠER: MEIOFAVNA IZOI.SKE LUKE PRED GRADITVIJO MARINI" iN PO NJEJ: PONOVLSENA RAZISKAVA - PRELIMINARNI REZULTATI, 75-78 UVOD Ob vrsti načrtnih raziskav meiofavne našega dela Tržaškega zaliva se je zlasti v zadnjih dveh desetletjih nabralo precej manjših preiskav meiofavne, deloma samostojne narave, večinoma pa kot sestavni de! različno zastavljenih naročniških ekspertiz, strokovnih mnenj ali lokalnih študij. Ker je večina tovrstnih del vezana v glavnem na ugotavljanje obstoječega oz. zatečenega, t.i. "ničelnega" stanja pred večjimi posegi v morsko okolje (npr. graditvijo luk, marin ali marikuftur), nam ponovitev takih vzorčevanj daje dragoceno priložnost ugotavljanja morebitnih biocenotskih sprememb okolja na osnovi časovnih primerjav. Menimo, da je mogoče tudi s takšnimi, še neobjavljenimi, po obsegu in ciljih skromnejšimi študijami prispevati k boljšemu poznavanju našega obalnega pasu. Zato nameravamo s časovnimi ponovitvami starejših raziskav meiofavne nadaljevati tudi v prihodnje. Ponovljena raziskava Strunjanskega zaliva (Vrišer, 1999) nam je kot prva iz te serije lahko vzorčni primer tovrstnega pristopa. Pričujoči prispevek podaja časovno primerjavo dveh enakih (iste lokacije, enaka metodika) kvalitativnih in kvantitativnih posnetkov stanja meiofavne s področja ožjega akvatorija in neposredne okolice izolske luke iz obdobja pred graditvijo marine (1991) in osem let kasneje (1999). EKOLOŠKE ZNAČILNOSTI IZOLSKEGA ZALIVA Širše področje Izolske luke sestavlja polkrožen, proti zahodu odprt zaliv, ki ga s severa zapira stari luški valolom, nov velik valobran marine pa od severozahoda. Vso vzhodno in južno stran zaliva obdaja pretežno zidana pristaniška obala z zaledjem turističnih in industrijskih objektov. Morsko dno v področju stare luke (Si. 1, postaja A) je fini ilni mulj sulfidnega značaja, črne barve, s tankim aerobnim površinskim slojem (1 cm, sivorjave barve). Na lokacijah B (vhod v današnjo marino) in C (zunaj luke in marine) prevladuje ilni mulj nesulfidnega značaja (siva glina) z debelejšim (2-3 cm) aerobnim površinskim slojem in primesjo finega peska. Makrobentoško združbo tega območja je raziskava 1981 leta (Vrišer ef a/., 1981) v floristično - favn ¡stičnem smislu razdelila v tri cone: 1) Zaradi dolgoletnega onesnaženja, pretežno organskega izvora (kanalizacija in odpadki predelovalne industrije), je ta močno degradirana cona obsegala področje stare luke (lokacija A) s prevladujočo morsko solato Ulva rígida. Favna te združbe je bila nizke diverzitete z maloštevilnimi, 15 vrstami. Še največ je bilo poiihetnih črvov in školjk, a od slednjih le ene same vrste. 2) V coni prehodnega pasu (postaja B) smo sicer še našli manjše količine morske solate, prav tako brez morskih trav, kot v bolj onesnaženi coni, a s favno precej višjega števila, 20 vrst. 3) Tretjo cono (njen zunanji del ponazarja postaja C) na že bolj peščenem sedimentu so ob obali naseljevali redki sestoji morskih trav Cymodocea nodosa, številne školjke in poliheti, skupno 38 vrst makrobentoškth rastlin in živali. Po skromnejši rasti trav in hkratnemu uspe-vanju ulve pa lahko sklepamo, da je bil tudi ta pas leta 1981 še vedno pod vplivom onesnaženja. V obdobju po letu 1981 je bilo v celoti sanirano onesnaževanje Izolske luke, vendar pa je v zadnjem desetletju v njenem zahodnem delu zrasla obsežna marina (SI. 1). Si. 1: Raziskovano območje z vzorcevalnimi postajami. Fig. 1: Research area with sampling stations. MATERIAL IN METODE Vzorce meiofavne smo na področju Izolske luke odvzeli 27. 11. 1991 in 25. 11.1999 na 3 postajah: A, B in C (SI. 1) in jih nato laboratorijsko obdelali po standardnih metodah ekstrakcije (sejanje z izpiranjem) in separacije. Površinski sediment smo odvzeli z gravitacijsko sondo (Meischner & Rumohr, 1974) s pomočjo cevnega korerja (premer odprtine 3,5 cm) 5 cm globoko. Meiofavno smo ekstrahirali iz konserviranih vzorcev (5% formalin v morski vodi) s sejanjem (velikost 76 ANNAIES • Ser. hist. nat. 11 - 2001 1 (23) Borut VRIŠFR: MEIOFAVNA IZOLSKE LUKE PRED GRADITVIJO MARINE IN PO NJEj: PONOVLJENA RAZISKAVA - PRELIMINARNI REZULTATI, 75-73 mrežic 0,050 pm-1 mm) in dekantacijo po VVieserju (1960). Makrobentoški vzorci so bili odvzeti z grabilom Van Veen (0,1 m2), presejani skozi sita (2 mm) in shranjeni v 4% formaiinu. REZULTATI Meiofavno raziskovanih treh postaj, njeno sestavo in abundanco v letih 1991 in 1999 podajamo v tabeli 1. Analiza meiobentosa na postajah A, B in C je leta 1991 pokazala mešane značilnosti tako čistega kot tudi onesnaženega okolja, poznanega iz primerljivih študij stresnega okolja naše obale. Slednje veija zlasti za lokacijo A, ki je pokazala znake dolgotrajnih evtrofnih učinkov pretežno organskega onesnaženja industrijskega izvora. To se kaže v zvišani gostoti harpakti-koidnih kopepodov (Harpacticoida), ki naraščajo v smeri proti notranjosti Izolske iuke, medtem ko številnost bentoških polihetnih črvov (Poiychaeta) v tej smeri enakomerno upada. Po drugi strani pa je bila abundanca med meiofavno prevladujoče, dominantne skupine Nematoda in njena razporeditev na vseh treh raziskovanih postajah bolj značilna za neobremenjeno, čisto okolje. Ponovitev raziskave v letu 1999 (Tab. 1) je proti pričakovanju pokazala skoraj enake strukturne in kvantitativne vrednosti kot pred osmimi leti. Presenečajo zlasti abundance, razlike so celo manjše od pričakovanih naravnih oscilacij. RAZPRAVA Posegi v morsko okolje, velikostnega ranga postavitve velikih luških valobranov kot v našem primeru, so za meiobentoško favno obremenitev, ki jo lahko opredelimo kot najmanj dvojno ekološko motnjo. Na samem kraju in v neposredni bližini podvodnih nasutij oz. deponij gradbenega kamenja prihaja do odplavljanja in mešanja flokuientnih vrhnih slojev sedimenta in meio-favne v vodni stolpec (resuspenzija). V širši okolici nasuti}, do nekaj sto metrov oddaljenosti, naša vzorče-vanja so bila vsa znotraj te cone, pa ekološko motnjo povzroča posedanje (sedimentacija) finejših sestavin z vodo pomešanega anorganskega sedimenta in organskega detrita ter frakcij pasivnejše, manj vagilne meio-favne na morsko dno. Ekološka motnja sedimentacije je bila na raziskovanem območju opazna ie v nekajmesečni fazi grobih gradbenih del, pozneje pa le še občasno. Točnejših podatkov sedimentacije nimamo in bi jih lahko dale le kontinuirane specializirane terenske meritve. O vplivu ekoloških motenj najrazličnejših vrst na meiobentos obstaja v strokovni literaturi sicer pisana zbirka številnih študij, ki pa v veliki večini obravnavajo specifične vidike zelo ozko definiranih okvirov eksperimentalnega pristopa, tematsko slabo uporabnih za primerjavo z našimi opažanji. Tako se lahko npr. motnja razkopavanja in mešanja sedimenta z vodnim slojem negativno odraža v meio-favni le kratkoročno in se nato združba običajno nor- postaja / station A j postaja / station B postaja / station C a b c sred. vred. / meanj a b c sred. vred. / mean a b c sred. vred. / mean 1991 Nematoda 384 480 836 566,6 732 488 1300 840,0 532 500 472 501,3 Harpacticoida 148 168 240 185,3 48 164 104 105,3 60 112 88 86,6 Poiychaeta 8 8 20 12,0 28 4 8 13,3 12 28 40 26,6 Oligocbaeta U S 12 10,6 16 28 28 24,0 20 4 12 12,0 Turbellaria 8 8 5,3 16 20 12,0 12 4 5,3 Bivalvia 4 1,3 Hydro idea 4 1,3 1999 Nematoda 448 506 816 590,0 473 1241 747 808,0 483 490 496 489,6 Harpacticoida 179 137 242 186,0 177 36 101 104,6 92 108 54 84,6 Poiychaeta 10 14 12 12,0 8 32 4 14,6 41 27 18 28,6 Oligochaeta 6 6 17 9,6 10 19 30 19,6 14 6 19 13,0 Turbellaria 2 6 7 5 7 21 3 10,3 7 7 6 6,6 BivaIvia 1 3 1,6 Ostracoda 1 0,3 1 0,3 Kinorhyncha 1 0,3 Tab. 1; Struktura in abundanca (št. os. /10 cm2, paralelke a, b, c in srednja vrednost) meiofavne na postajah A, B in C v ietih 1991 in 1999. Tab. 1: Meiofaunal community structure and abundance (No. ind. /10 cm2, replicates a, b and c, and mean value) at stations A, B and C in 1991 and 1999. 77 ANNALES Ser. hist. nat. 11 - 2001 1 (23) Boral VRIŠER: MEIOFAVNA IZOLSKE LUKE PRED GRADITVIJO MARINE IN PO NJEJ: PONOVLJENA RAZISKAVA - PRELIMINARNI REZULTATI, 7S-76 malizira (v primeru, da ni močnih tokov) že po nekaj dneh (Fegley, 1987; Sherman & Coutl, 1980). Vplivi sedimentacije so nasploh lahko precej raznovrstni. Vse od možnosti prostorsko mozaično strukturi ranega povečanja produktivnosti posameznih skupin meiofavne (Grassle & Sanders, 1973; Johnson, 1970), najverjetneje zaradi zmanjšanja tekmovalnosti (o tem obstoji vrsta delovnih hipotez), pa do očitnega nazadovanja združb v primerih močne lokalne sedimentacije (Rhoads et al., 1978). Primeri zadnje so najizrazitejši v tistih luških akvatorijih, ki so pod stalnim vplivom vzdrževalnih del (dredžanja, vzdrževalna poglabljanja plovnih poti), kot je to opaziti s skromno meiofavno tudi na ožjem območju luke Koper. Ocenjujemo, da je bila ekspozicija sedimentacijske obremenitve v našem primeru verjetno prekratka ali pa prešibka, da bi pustila vidne posledice na ravni gostote glavnih skupin meiofavne, morebitne spremembe znotraj ustroja dominantnih skupin (npr. Harpacticoida) pa bodo še predmet nadaljnjih analiz. Gledano v celoti, lahko na osnovi obeh pregledov (1991, 1999) ugotovimo, da je srednja abundanca meiofavne raziskovanega območja sicer višja, kot je običajno v primerljivih razmerah onesnaženega okolja, a vendarle nižja kot v čistem okolju. V raziskovani meiofavni nasploh ni opaziti bistvenih posebnosti, le lokacija A v notranjosti luke izkazuje nekatere poteze zmerno onesnaženega okolja. Ponovljena raziskava je v mejah uporabljenih metod pokazala, da se gradbeni posegi (valolom, pomoli, preureditev obalne črte) niso neposredno pokazali na obstoječi združbi meiofavne. Ugotavljamo, da saniranje onesnaženja v stari izolski luki v smeri izboljšanja ekoloških razmer, a po drugi strani povečana stagnantnost z marino ograjenega akvatorija v smeri potencialnega poslabšanja stanja za zdaj v opazovanem časovnem razponu niso povzročili v meiobentosu raziskovanega področja opaznih sprememb. Zaradi zadnjih, novih dodatnih gradbenih posegov v ta morski prostor in še manjkajočih taksonomskih preiskav bomo z vzorčevanji nadaljevali in v tem smislu predstavljene rezultate opredeljujemo kot preliminarne. MEiOFAUNA OF THE ¡ZOLA HARBOUR AREA 8 YEARS AFTER THE NEW MARINA WAS COMPLETED: A REPEATED INVESTIGATION - PRELIMINARY RESULTS Borut VRISER National Institute of Biology, Marine Biology Station, Si-6330 Piran, Fornace 45 SUMMARY To establish potential changes in meiofaunal community, a sampling in the Izola harbour area (Gulf of Trieste, Northern Adriatic) was repeated 8 years (November 1991, November 1999) after the large new marina was completed. Recent, still preliminary results show almost identical structural and quantitative characteristics of the meiofauna as in the year 1991. It seems that in our case the main ecological disturbance - the sedimentation of suspended sediment, well known from the literature - was not long (or intensive) enough to cause visible changes on the level of main meiofaunal groups. More detailed taxonomic analyses on harpacticoid copepods (Harpacticoida, Cope-poda) of the area will follow. Key words: meiofauna, Port of ¡zola, repeated investigation LITERATURA Fegley, S. R. (1987): Experimental variation of near-bot-tom current speeds and its effects on depth distribution of sand-living meiofauna. Mar. Biol., 95, 183-191. Grassle,. J. F. & H. L. Sanders (1973): Life histories and the role of disturbance. Deep-Sea Res., 20, 643-659. Johnson, R. G. (1970): Variations in diversity within benthic marine communities. Am. Nat., 104, 285-300. Meischner, D. & j. Rumohr (1974): A light-weight, high-momentum gravity corer for subacqueous sediments. Senckenbergiana Marit, 6(1), 105-117. Rhoads, D. C, P. L. Mc Call & J. Y. Ymgst (1978): Disturbance and production on the estuarine seafloor. Am. Sclent., 66, 577-586. Sherman, K. M. & B. C. Coull (1980): The response of meiofauna to sediment disturbance, j. Exp. mar. Biol. Ecol., 46, 59-71. Vrišer, B. (1999): Meiofavna Strunjanskega zaliva 18 let pozneje: Ponovljena raziskava. Annates, 17, 209-212. Vrišer, B., A. Avčin & A. Vukovič (1981): Značilnosti bentoških združb v Izolskem zalivu. Slov. morje in zal., 4-5, 201-206. Wieser, W. (1960): Benthic studies in Buzzards Bay. II. The meiofauna. Limnol. Oceanogr., 5, 121 -137. 78 VARSTVO NARAVE TUTELA DELL'AMBIENTE NATURE CONSERVATION ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) professional paper UDC 598.9(497.5) received: 23.5.2001 ELEONORA'S FALCON (EALCO ELEONORAE, GENE 1839) IN CROATIA: RANGE, THREATS AND THE PROPOSAL OF ACTION AND MANAGEMENT PLAN Gvido PIASEVOU Public Institution for the Management of Protected Areas in the County of Split and Dalrnatia, HR-21000 Split, Prilaz braCe Kaliterna 10 E-mail: Gvido.Piasevoli@dalmatian-nature.br Vlatka 5CETARIC "Karrtiks Eko d.o.o.", HK-10250 Zagreb-l.uiko, Franje PuSkariCa 18 ABSTRACT Eieonora's Falcon is classified as rare in Europe. This species is also included in the first group of priorities for the protection of biological diversity by the Ministry of Environment and Physical Planning of the Republic of Croatia. Croatian population of Eieonora's Falcon has not been sufficiently researched and its nest sites have not been protected so far. We have been investigating Eieonora's Falcon population in Croatia for three years. The research consisted of two main parts - study of the breeding ecology of colony F3 and census of the entire Croatian population. The population was estimated at 58-68 breeding pairs in six colonies and we made a proposal as to the action and management plan for this species in Croatia. Key words: Ealco eleonorae, Eieonora's Falcon, Croatia, action plan, management plan FALCO DELLA REGiNA (FALCO ELEONORAE GENE 1839) IN CROAZIA: DISTRIBUZIONE, PERICOLI E PROPOSTA DEL PIANO DI AZIONE E GESTIONE SINTESI II Falco della Regina in Europa é classificato come specie rara. II suo nome é stato inserito nel primo gruppo delle prioritä per la tutela della diversitä bt'ologica dal Ministero per ¡'ambiente della Repubblica di Croazia. La po-polazione del Falco della Regina in Croazia non é stata studiata a sufficienza e i suoi siti di nidificazione non vengo no ancora tutelad. Da tre anni gli autori studiano la popolazione del Falco della Regina in Croazia. La ricerca comprende lo studio delle modalitä di riproduzione della colonia F3 nonché il censirnento dell'intera popolazione. Si stima che questa comprenda 58-68 coppie in sei colonie. Gli autori hanno ultímato la proposta per il piano di azione e gestione di questa specie in Croazia. Parole chiave: Falco eleonorae, Falco della Regina, Croazia, piano di azione, piano di gestione 81 ANNALES • Ser. hist. nat. 11 • 2001 • 1 (23) Gvido PEAS EVO LI & Vlalka ŠČETAKIČ: ELEONORA'S FAICON (FALCO EIEONORAE, GENE 1839) ..., 81-86 INTRODUCTION RESULTS Eleonora's Falcon (Falco eieonorae, Gene 1839) breeds mostly in the Mediterranean region. The total population of this species, which is classified as rare at the European level (Tucker & Heath, 1994), is estimated at some 6320 pairs (Ristow, in print). The species is also included in the first group of priorities for the protection of biological diversity by the Ministry of Environment and Physical Planning of the Republic of Croatia (Državna uprava za zaštifu prirode i okoliša, 1999). The Croatian population of Eleonora's Falcon has not been sufficiently researched enough and most of the data are based on accidental and occasional observations (jova-novič, 1972; Krpan, 1965, 1980; Lukač el al., 1997). It's nest sites have not been protected so far. MATERIAL AND METHODS We have been studying the population of Eleonora's Falcon in Croatia for three years - 1998, 1999 and 2000 (Tab. 1). The research consisted of two main parts -study of the bird's breeding ecology in colony F3 and census of its total Croatian population. Tab. 1: Years, locations and dates of the carried out fieldwork. Tab. 1: Leta, lokacije in datumi terenskega dela. YEAR LOCATION DATE 1998 Colony F3 July 25-30 September 10-11 1999 Colony F3 August 03-08 September 13 2000 Colony F3 Islands of the Central and South Adriatic (census) August 07-13 September 12-21 August 19-31 The codes of the colonies are according to Waiter (1978). During the research, the birds were observed by binoculars BPC 7x50 and 8PC4 8x30 and the telescope Opticron HR66 45R from boat cruising along the cliffs and, in some cases, from various islands. During observations from the boat, birds were startled by a special siren in order to make them fly away from their nest sites and thus to enable us to make all the necessary records. The census was made with ti?e aid of eleven metres long sailing ship and a small boat at the following Central and South Adriatic islands: Dugi otok, Kornati Isles, jabuka, Kamik, Svetac, Bisevo, Vis, Greben, Susac, Bi-jelac, Lastovo, KorCula, Mljet and Elafiti Isles. The 1997 data from Palagru2a are also included in the census. Foreign experience and recommendations (Ristow, in print) were used, too. Population of Eleonora's Falcon in Croatia During the first census of Eleonora's Falcon in Croatia, six colonies were registered (Tab. 2). Tab. 2: Colonies and a number of breeding pairs estimated during the 2000 census. Tab. 2: Kolonije in število gnezdečih parov, ugotovljenih med štetjem leta 2000. COLONY NUMBER OF PAIRS F2 6-8 F3 38-42 F4 2 F6 3-4 F7 5-7 F8 4-5 The colonies are situated on five Central Dalmatian islands and defined according to Walter (1979) and Ristow eta!. (1989). The area of distribution Island A covers 4.6 square kilometres. It is temporarily inhabited, with a low level of agriculture, mostly vineyards and Mediterranean vegetation, predominantly maquis and pine forests. Island 8 covers 0.08 square kilometres, it is uninhabited and with very poor vegetation. These two islands are the sites of colony F3. Fig. 1: Eleonora's falcon (Falco eieonorae). (Photo: D. Ristow) SI. 1: Sredozemski sokol (Falco eieonorae). (Foto: D. Ristow) 82 ANNALES • Ser. hist. nat. -11 2001 1 (23) Gvido PIASEVOU & Vbtka SCETARid: ELEONORA'S FALCON (f-ALCO ELEONORAE, GENE ! 839)..., 8Î-86 island C covers 90.3 square kilometres and is inhabited, with various activities practised there, such as tourism, agriculture, hunting, traffic and fishing. Colonies F2 and F6 are situated on this island. Island D is 5.8 square kilometres large with several permanent inhabitants and a low level of agriculture. During the summer there are some tourist activities practised on this island and around it Colonies F7 and F8 are situated on this island. Island E is 0.4 square kilometres large, uninhabited and with some low vegetation. Colony F4 is situated on it. DISCUSSION Potential threats and limiting factors Natural factors Nests of the Eleonora's Falcon could be naturally endangered by various predators, such as snakes, ravens, gulls or some raptor species. Adult falcons are able to defend their nests, and the predators mentioned above should thus not threaten the population. Some parasites and diseases, such as Mallopbaga, Haemaphy-salis hoody and a form of malaria, were also registered in some colonies (Ristow & Wink, 1985), but they do not essentially affect the size of the colonies. introduction of allochtonous species to the islands with Eleonora's Falcon colonies Over 90% of the Croatian population breeds on large inhabited or temporarily inhabited islands. Various predators or other allochtonous species (cats, dogs, rabbits, rate, sheep and so on) were colonized on those islands long ago, and it is likely that their density on some islands has declined due to the depopulation. Hunting and illegal trade In the past, the locals were known to eat the nestlings, but this custom has practically disappeared. There is some possibility of an occasional, accidental poaching, and this species could also be interesting for egg collectors due to its rarity. Eleonora's Falcon is not interesting for falconry purposes. Pressures on the bird's nest sites Intensive urbanization and sea traffic close to the colonies could be very detrimental for the breeding birds. During the parents' absence, the eggs or young could be attacked by predators, and embryos in eggs could be destroyed due to overheating, if eggs are directly exposed to the sun. Fig. 2: Nestling of the Eleonora's falcon. (Photo: G. Pia-sevoli) Si 2: Mladič sredozemskega sokola. (Foto: G. Piasevoli) Habitat degradation Disappearance of natural vegetation and intensive agriculture could reduce the food sources for falcons. Forest fires could be a potential cause of disappearance of natural vegetation. Drinking water is also important for the bird's colonies. Small pools, the only reserves of drinking water for falcons, are not maintained nowadays and are rapidly disappearing due to depopulation and decreasing agriculture. Poisoning irresponsible usage of agricultural chemical agents could cause poisoning. This, however, has not been registered in Croatia so far, but it has certainly been recorded In some other countries (Ristow, 2001) and could thus be expected here as well. Aims and proposed actions Trends and oscillations regarding the size of the population are completely unknown due to the insufficient research so far. it is necessary, however, that at least the Falcon's present numbers are retained through protection. The following measures should be undertaken: f. Legal aspect 1. 1. To declare protection of all nest sites by the Nature Protection Law as special reserves or nature monuments and to include them in large marine and pelagic islands as a protected and sustainably managed area; 1.2. to prevent eventual nest plundering with certain 83 ANNALES • Ser. hist. nat. -11- 2001 • 1 (23) Oído PIASEVOU & Viatka ŠČETAR1Č: EtEONORA'S FALCON (FALCO ELEONORA^ CENE 1839)..., 81-86 protection measures in every reserve or nature monument; 1. 3. not to allow hunting activities^ the hinterland of the colonies before November 1' ; 1. 4. to authorize persons to monitor and guard the colonies, i.e. to immediate intervene and prevent people breaking the law; 1. 5. to include the protection of the colonies in the complete regional and national strategy of the coastal zone development. 2. Economic activities development policy 2. 1. To protect colonies from various pressures caused by too heavy traffic of tourist ships and aircraft; to stimulate development of sustainable, ecological tourism, whose main resource should be well preserved nature; to prevent any extensive building of new tourist accommodation capacities and other structures on the low urbanized small islands with the Falcon's colonies, especially close to them; 2. 2. to stimulate organic agriculture on the islands, with minimal use of pesticides and herbicides. 3. International cooperation 3. 1. To ensure a coordination of the national action plan with the adequate plans at the international level. Fig. 3: Nest of the Eleonora's falcon with huge remains of feathers of preys in front of it (Photo: G. Pi ase voli) Si 3: Gnezdo sredozemskega sokola z lepo vidnimi ostanki perja različnih vrst njegovega plena. (Foto: G. Piasevoli) 4. Habitat protection 4. 1. To ensure natural succession of vegetation in the large parts of the islands, which are known as the Falcon's hunting grounds. Forrest management should be under control by nature conservation institutions; 4. 2. to ensure continuos maintenance of small water habitats, in order to prevent them from drying up during the summer; 4. 3. to prevent introduction of aflochthonous species to the small islands. 5. Research and monitoring 5. 1.To carry out a census of the entire population every year; 5. 2. to carry out a detailed research in one colony. Research should include counting of eggs and chicks, establishing the breeding success, taking samples of blood and food remains, measuring the eggs, bird ringing and other methods of marking (including satellite tracking), registering the losses in the colony and reasons for them, and observation of any other parameters of the breeding ecology; 5. 3. To observe any eventual changes in all colonies, by temporary short surveys and to react if necessary; 5. 4. to ensure financial and technical conditions for the planned research and monitoring. 6. Public awareness raising 6. 1. To raise the awareness - especially of the locals, young people and boat owners - of the need to protect the Eieonora's Falcon, 6. 2. to raise the awareness that preserved nature is a potentially important economic, primarily tourist, resource; 6. 3. to prepare printed and other materials in Croatian and foreign languages; 6. 4. to cooperate with NGOs; 6. 5. to set up tourist information centres for the natural riches of pelagic islands and marine ecosystems; 6. 6. to cooperate with the maritime police and to train their officers. Proposed implementers and the duration of the plan This plan should be implemented by the Ministry of Environment and Physical Planning of the Republic of Croatia and the Public Institution for the Management of Protected Areas in the County of Split and Dalmatia. it should be continual. 84 ANNALES • Ser. hist. nat. • 11 ■ 2001 • 1 (23) Gvido PIASEVOll J, Vtatka SČETARIČ: Ei.EONORA'S FALCON (MiCO ELLONORAE, GENE 1839) ..., 81-86 CONCLUSIONS Eleonora's Falcon is classified as a rare species in Europe and, during the first census, the Croatian population was estimated at 58-68 breeding pairs. This is the reason why this species can be considered as potentially endangered in Croatia. Therefore, it is necessary to make an action and management plan for its population in Croatia. The plan is based on the data collected so far. it con- sists of the data on the number of birds and colonies, potential threats and limiting factors as well as aims with proposed actions. ACKNOWLEDGEMENTS We would like to thank Dr Dietrich Ristow for his friendly and selfless suggestions, advice and help during our work. SREDOZEMSKI SOKOL (FALCO ELEONORAE, GENE 1839) NA HRVAŠKEM: NJEGOVA RAZŠIRJENOST, OGROŽENOST iN PREDLOG ZA AKCIJSKI NAČRT iN NAČRT UPRAVLJANJA Cvido PIASEVOL I Public Institution for the Management of Protected Areas in the County of Split and Dalmatia, HR-21000 Split, Pritaz brace Kalitema 10 E-mail: Gvido.Piasevoli@dalfriatian-nature.hr Vlatka ŠČETARIČ "Katniks Eko d.o.o.", HR-10250 Zagreb-Lučko, Franje Puskariča 18 POVZETEK Sredozemski sokol je opredeljen kot redka evropska ptica in vključen v prvo skupino prioritet v ohranjanju biot-ske raznovrstnosti, kot jih navaja HrvaŠko Ministrstvo za okolje in prostor. Hrvaška populacija sredozemskega sokola še ni bila ustrezno raziskana in tudi gnezdišča te ujede še niso zaščitena. Glede na to, da je ta vrsta redka in zatorej potencialno ogrožena, je bilo treba pripraviti ustrezen akcijski načrt in načrt upravljanja. Populacijo sredozemskega sokola na Hrvaškem smo raziskovali tri leta, in sicer v sklopu preučevanja njegove gnezdltvene ekologije v koloniji E3 in štetja celotne hrvaške populacije. Potem ko je bilo ocenjeno, da v šestih kolonijah gnezdi od 58 do 68 parov, je bil pripravljen osnutek akcijskega načrta in načrta upravljanja za to vrsto na Hrvaškem. Potencialne nevarnosti za hrvaško populacijo sredozemskega sokola so naravni dejavniki, naseljevanje alohtonih vrst na otoke, kjer gnezdi ta ptica, lov in nelegalna trgovina, posegi v prostor s sokolovimi gnezdišči, degradacija habltata in zastrupljanje narave. Glavni namen načrta je ohraniti vsaj današnjo populacijo sredozemskega sokola, kar naj bi dosegli s pripravo in uresničevanjem zakonskih predpisov, nadzorom nad gospodarskimi dejavnostmi, mednarodnim sodelovanjem, zaščito habitata, raziskovalnimi dejavnostmi, spremljanjem stanja (monitoringom) in z ozaveščanjem javnosti. Ključne besede: Falco eleonorae, sredozemski sokol, Hrvaška, akcijski načrt, načrt upravljanja 85 ANNALES Ser. hist. nat. • 11 • 2001 • 1 (23) Cwdo PIASEVOLI & VUtk« ŠdETARIČ: ElEONOKA-S EALCON {MiCO ELEONORAE, G£NE 1839) .... 81-86 REFERENCES Državna uprava za zaštitu prtrode i okoliša (1999): Pregled stanja biološke i krajobrazne raznolikosti Hrvatske sa strateg i jom i akcijskim planovima zaštite. Zagreb. Jovanovič, V. (1972): Nova posmatranja sokola mrkog, Falco eleonorae, na jadranskim otocima. Larus, 24, 161-162. Krpan, M. (1965): Ptice otoka Visa i njemu bližih oto-dda. Larus, 16-18, 106-150. Krpan, M. (1980): Srednjodalmatinska ornitofauna. Larus, 31-32, 97-156. LukaC, G., M. Stipčevid & N. Tvrtkovič (1997): The status and distribution of Eleonora's Falcon (Falco eleonorae, Gene 1834) in Croatia. Natura Croatica, 6(3), 323-333. Ristow, D. (2001): Poison Is Causing the Sudden Population Decline of Eleonora's Falcon. Internationa! Hawkwatcher, 3, 10-17. Ristow, D. (in print): Eleonora's Falcon Falco eleonorae Action Plan. Ristow, D. & M. Wink (1985): Breeding Success and Conservation Management of Eleonora's Falcon. ICBP Technical Publication No. 5, 147-152. Ristow, D., W. Scharlau & M. Wink (1989): Population Structure and Mortality of Eleonora's Falcon Falco eleonorae, Raptors in the Modern World, p. 321-326. Tucker, G. M. & M. F. Heath (1994): Birds in Europe, Their Conservation Status. BsrdLife Conservation Series No. 3, 194-195. Walter, H. (1978): Breeding Locations of Falco eleonorae. University of California, Los Angeles, USA. Walter, H. (1979): Eleonora's Falcon: Adaptations to Prey and Habitat in a Social Raptor, University of California, Los Angeles, USA. 86 ANNALES • Ser. hist. nat. • 11 2001 • 1 (23) strokovni članek UDK 502.72:574.2(262) prejeto: 14.4.2001 ZAVAROVANA OBMOČJA KOT ORODJE ZA OHRANJANJE BIODIVERZiTETE V SREDOZEMLJU Andrej SOVINC Vodnogospodarski inštitut, Si-'!000 Ljubljana, Hajdrihova 28c E- m a ¡!: a nd re j .s o vi n c @ gu est. arries. s i IZVLEČEK Glede na izgubo mokrišč v sredozemskih državah v zadnjih nekaj desetletjih in zaradi vse večjih zahtev turizma in drugih prostorskih načrtovanj v teh državah postaja jasno, da biodiverzitete v Sredozemlju, posebno na mokriSčih in obalnih območjih, ne bo mogoče ohraniti zgolj s sonaravno uporabo virov. Avtor opozarja, da so zavarovana območja eno najučinkovitejših sredstev za ohranjanje biodiverzitete in situ. Ključne besede: zavarovana območja, biodiverziteta, varstvo narave, Sredozemlje LE AREE PROTETTE COME STRUMENTO PER LA CONSERVAZiONE DELLA BIODiVERSITÁ NEL MEDITERRANEO 51NTESI Nei paesi mediterranei, vista la perdita degli ambienti umidi e le crescenti richieste di spazio degli uitimi decenni da parte dei settori turístico ed urbanístico, appare chiaro che la biodiversitá nel Mediterráneo, soprattutto nelle zone umide e costíere, non puó venir tutélala con la sola gestione delle risorse natural/', i 'autore sottolinea come le aree protette si siano rivelate uno fra gli strumenti piü eíficací per la conservazione della biodiversitá in situ. Parole chiave: aree protette, biodiversitá, tutela dell'ambiente, Mediterráneo 87 ANNALES • Ser. hist, nat. • 11 • 2001 ■ 1 (23) Andrej SOVINC: ZAVAROVANA OBMOČJA KOT ORODJE ZA OHRANJANJE BiODIVERZITETE V SREDOZlMUU, 87-92 UVOD V naši zavesti se vse bolj krepi spoznanje, da je varstvo narave in okolja ne le neodtujljiva pravica in odgovornost narodov in njihovih držav, temveč skupna odgovornost - v našem odnosu do sosednjih držav - pa tudi skrb celotnega človeštva. Zavarovana območja so po splošnem mnenju eno najučinkovitejših sredstev za ohranjanje bi od i verz i tete in situ, kar je tudi poudarjeno v 8. členu Konvencije o biotski raznovrstnosti. Seveda pa zavarovana območja niso edini način za ohranjanje narave in pokrajine. Prej bi rekli, da so vrhunec naravovarstvenih prizadevanj, nekakšen model za ohranjanje pokrajine v širšem smislu. Zavarovana območja so še posebno pomembna, ker na najboljši način - v večini primerov tudi edini -ohranjajo biodiverziteto. Naravni rezervati in narodni parki so najprimernejši za zavarovanje redkih in ogroženih vrst, saj zagotavljajo, da se ohranjajo značilni vzorci različnih tipov habitatov. Poleg tega so zavarovane pokrajine (krajinski in regijski parki) učinkovito sredstvo za ohranjanje načina življenja, ki je v sozvočju z naravo in vzorčni primer za iskanje oblik sonaravnega razvoja podeželja. Zavarovana območja tudi bogatijo kakovost človekovega življenja, predvsem kot prostor za rekreacijo. Dajejo nam priložnost za navdih, pa tudi prostor za sproščanje, uživanje in učenje. Predvsem pa so vir človekove umske, telesne in duhovne obnove. Pa vendar zavarovana območja pokrivajo Evropo zelo neenakomerno in tudi sistem zavarovanih območij je po mednarodnih merilih precej neučinkovit. V tem smislu je treba razumeti prizadevanja Svetovne zveze za ohranitev narave IUCN (The World Conservation Union), Svetovnega sklada za naravo (WWF -The World Wide Fund for Nature), Evropske zveze naravnih in narodnih parkov (EUROPARC Federation), Svetovnega centra za ohranitev narave (World Conservation Monitoring Center) in BirdLife International, da uresničijo prvi akcijski načrt, imenovan "Parki za življenje", za zavarovana območja v Evropi. Načrt je rezultat sodelovanja med državami, vladnimi službami in agencijami, nevladnimi organizacijami in posamezniki v Evropi in je nekakšen evropski konsenz o tem, kakšno delo je še treba opraviti na tem področju. Kakšen je namen akcijskega načrta? Odgovor na to vprašanje je leta 1994 zapisala Komisija za narodne parke in zavarovana območja (WCPA) in se glasi takole: "Da zagofow ustrezno in učinkovito omrežje primerno upravljanih zavarovanih območij v Evropi." Kakšne dejavnosti obsega akcijski načrt? "Parki za življenje" je dokument, ki je nastal z na- menom pomagati vladam in upravljalcem zavarovanih območij, da zagotovijo ustrezno in učinkovito omrežje dobro upravljanih zavarovanih območij v Evropi. Načrt obsega tri vrste dejavnosti. Prvič, vsebuje mnoge že obstoječe pobude, ki govorijo, da je bilo v Evropi na področju zavarovanih območij že veliko narejenega. Drugič, daje nasvete, predvsem vladam, glede zavarovanih območij, še posebej vključevanje zavarovanih območij v postopkih načrtovanja kmetijskih, gozdarskih, turističnih in drugih planskih odločitev. Tretjič, predvideva, da bodo uresničeni tako imenovani prednostni projekti, ki bodo obravnavali specifično problematiko načrtovanja in upravljanja z zavarovanimi območji. Svetovna mreža zavarovanih območij obsega več kot 30.000 območij (ta analiza zajema vsa zavarovana območja, ne glede na njihovo velikost). Skupna zavarovana površina presega 13 milijonov km2, kar pomeni nekaj več kot 9% kopnega. Evropska mreža obsega 9.3.35 zavarovanih območij na več kot 600,000 km3 ali na 12% njene celotne kopenske površine (WCMC, 1994). Si. 1: Konji na paši v francoskem mokrišču Camargue. (Foto: I. Škornik) Fig. 1: Horses at the pasture in the French wetland Camargue, (Photo: L Škornik) MEDNARODNI DOGOVORI IN DRUGE POBUDE ZA ZAVAROVANA OBMOČ|A V SREDOZEMSKI REGIJI Poleg že omenjene Konvencije o biotski raznovrstnosti so za razglašanje zavarovanih območij v srednjeevropskem in sredozemskem prostoru pomembni še naslednji mednarodni dogovori (podrobneje so predstavljeni v Skoberne, 1997): Ramsarska konvencija (1971) Konvencija o mokriščih, ki imajo mednarodni pomen, zlasti kot prebivališča močvirskih ptic (Ram- 88 ANNALES • Ser. hist. nat. -11- 2001 • 1 (23) Andrej SOVINC: ZAVAROVANA OBMOČJA KOT ORODJE ZA OHRANJANJE BIODIVERZITETE V SREDOZEMLJU, 87-92 sarska konvencija), je bif prvi svetovni sporazum o varovanju in razumni rabi naravnih virov. Ramsarska konvencija je okvir za mednarodno sodelovanje pri varovanju in razumni rabi mokrišč. Konvencija je podrobneje predstavljena v publikaciji Ramsarska konvencija in slovenska mokrišča (Sovine, 1999). Pobuda MedVVet MedVVet je dolgoročna regionalna pobuda pod pokroviteljstvom Ramsarske konvencije in drugih vladnih in nevladnih organizacij, katerih namen je zavarovati sredozemska mokrišča in spodbujati k njihovi razumni rabi. Med "Konferenco o sredozemskih mokriščih" v Benetkah leta 1996 je bila potrjena tako imenovana "Strategija za sredozemska mokrišča", ki temelji na "Strateškem načrtu 1997-2002 Ramsarske konvencije". Njen glavni namen je zaustaviti degradacijo ali uničevanje sredozemskih mokrišč in tako prispevati k ohranjanju biodiverzitete in sonaravnega razvoja v tem območju. V njej je navedena vrsta splošnih ciljev, ki naj bi jih dosegli z različnimi akcijami na mednarodni, regionalni in lokalni ravni. Konvencija o svetovni dediščini (1972) Osnovno poslanstvo te konvencije o varovanju svetovne kulturne in naravne dediščine je natančno definirati in ohraniti to dediščino. Naravna dediščina je definirana kot: "skupek naravnih značilnosti, sestoječih iz fizičnih in bioloških formacij ali skupin takšnih formacij, ki so izjemne svetovne vrednosti z estetskega ali znanstvenega vidika", kot "geološke in fiziografske formacije in natančno določena območja, ki zajemajo habítate ogroženih Živalskih in rastlinskih vrst izjemne svetovne vrednosti z vidika znanosti aH ohranjanja narave", in/ali kot "naravne lokalitete aH natančno določena naravna območja izjemne svetovne vrednosti z vidika znanosti, ohranjanja narave ali naravne lepote". UNESCO bi o sferni program (1976) Ta interdisciplinarni program raziskovanja in usposabljanja v okviru naravoslovnih in družboslovnih ved je namenjen spodbujanju razumne rabe in varovanju virov v biosferi ter izboljševanju odnosov med ljudmi in okoljem po vsem svetu. Sloni na oblikovanju in upravljanju biogeografsko reprezentativne mreže biosfernih rezervatov, kjer se ohranjanje ekosistemov in njihove biodiverzitete povezuje s sonaravno uporabo naravnih virov, ustreznimi raziskavami, spremljanjem stanja (mo-nitoringom) in izobraževanjem v dobro krajevnih skupnosti. Smernica EU za varstvo ptičev (1979) S temi smernicami Evropske zveze so bile članicam Evropske unije naložene stroge pravne obveznosti, med njimi tudi ta, da je treba znotraj posebno varovanih območij ohranjati populacije prostoživečih ptic. Smernice EU FFH ("flora, favna, habitati"; 1992) Namen teh smernic Evropske zveze je zagotoviti ohranitev biodiverzitete z varovanjem naravnih habi-tatov prostoživečih živali. V smernicah je predvideno, da se najkasneje do leta 2000 osnuje omrežje varovanih območij v Evropski zvezi. S tem omrežjem, ki ji pravimo tudi Natura 2000, naj bi ohranjali razširjenost in številnost ogroženih vrst in habitatov, tako kopenskih kot morskih. Natura 2000 zajema tudi območja za posebno varovanje, tako kot to določajo Smernice za varstvo ptičev. Takšna območja so lokalitete, ki so pomembne za vso evropsko skupnost in jih članice Evropske zveze zavarujejo s pravnimi, administrativnimi in/ali pogodbenimi akti, ki določajo, da je treba za ohranjanje naravnih habitatov in populacij vrst, ki so jim lokalitete namenjene, upoštevati potrebne varstvene ukrepe. Barcelonska konvencija (1976) Prvotni namen Barcelonske konvencije je bil zmanjšati onesnaževanje v Sredozemskem morju, teta 1982 je bil sprejet tretji predpis glede posebno zavarovanih območij v Sredozemskem morju, ki pa naj bi ga v kratkem nadomestili z novim (potrjen je bil že leta 1995), imenovanim "predpis za posebno zavarovana območja in biodiverziteto". Namen posebej zavarovanih območij je ohraniti: a) značilne tipe ustrezno velikih obalnih in morskih ekosistemov, da bi se zagotovila njihova dolgoročna sposobnost za življenje in ohranila njihova bio-diverziteta; b) habitate, ki jim grozi, da bodo v svojih naravnih sredozemskih območjih razširjenosti izginili, ali katerih območje se je zmanjšalo zaradi njihove re-gresije ali pa zaradi bistveno omejene površine; c) habitate s kritično stopnjo preživetja za močno ogrožene ali endemične živalske in rastlinske vrste; d) lokalitete posebnega pomena zaradi njihovih znanstvenih, estetskih, kulturnih ali izobraževalnih vrednosti. BIODIVERZ1TETA V SREDOZEMLJU V "Parkih za življenje" je sredozemsko območje obravnavano kot eno tistih, ki jih je treba obravnavati prednostno. Čeprav v sredozemskem bazenu ni ostalo skoraj nič od njegovega prvotnega naravnega okolja, ostaja zaradi svoje bogate krajinske in kulturne de- 89 ANNALES • Ser. hist, nat. 11 2001 - 1 (23) Andrej SOVINC: ZAVAROVANA OSMOČIA KOT ORODJE ZA OHRANJANJE BIODIVERZITETE V SREDOZEMLJU, 87■■92 diščine, izredno zanimive zgodovine in toplega podnebja eno najbolj priljubljenih evropskih letovišč. Zaradi takšnega razvoja in še cele vrste drugih okoliščin so ogroženi mnogi naravni viri, ki so se še ohranili v tem območju. Močno ogrožena so predvsem mokrišča: v zadnjih nekaj desetletjih je bilo v Grčiji, Franciji, Italiji in Španiji uničenih med 60 in 70% mokrišč. Sredozemsko območje je znano po pestri biodi-verziteti in endemičnih vrstah, posebno rastlinah, ki jih više na severu ni. Bogata je tudi ptičja favna, posebno zaradi številnih preletnib vrst. Sredozemsko morje je poleg tega dom morskih želv in nekaterih redkih sesalcev, kakršna je medvedjica (Monacbus monachus). To pomeni veliko odgovornost za vlade sredozemskih držav, saj k njihovim ozemljem sodi precejšen delež evropske biodiverzitete in še posebno ogroženih vrst Kakih 80% rastlinskih vrst, na primer, katerih rastišča in ha bi tate je treba zaščititi v skladu s smernicami Evropske zveze o habitatih, je prav iz sredozemskih držav. Tab, 1: Diverziteta višjih rastlin v sredozemskih in drugih evropskih državah (vir: WCMC, 1994). Tab. 1: Vascular plant? diversity in the Mediterranean and other European countries (source; WCMC, 1994). Giede na izgubo mokrišč v sredozemskih državah v zadnjih nekaj desetletjih in zaradi vse večjih zahtev turizma in drugih posegov v prostor v teh državah postaja jasno, da biodiverzitete v Sredozemlju, posebno na mokriščih in obalnih območjih, ne bo mogoče ohraniti zgolj s sonaravno uporabo virov. Če želimo, da se krhka in enkratna naravna dediščina v Sredozemlju ohrani, je treba temeljito spremeniti odnos do turizma in njegovega potencialno zelo škodljivega vpliva na bio-diverziteto in hkrati do tradicij in kultur v zavarovanih območjih. V nekaterih zavarovanih območjih turizma preprosto ne bi smelo biti! V "Parkih za življenje" je zapisano, da je poglavitni cilj sredozemske strategije o mokriščih "pravno zaščititi najpomembnejša mokrišča v tem območju". K temu dodajmo, da bi bilo treba čim več ogroženih sredozemskih naravnih ali naravi podobnih območij opredeliti kot zavarovana območja IUCN 1. in 2. kategorije (tako imenovani strogo določeni naravni rezervati in narodni parki) (IUCN, 1994). Preostala, še ohranjena večja sredozemska mokrišča, bi morala dobiti status narodnih parkov. Po drugi strani pa v Sredozemlju, kjer je voda redka dobrina, obstajajo prezrta mnoga manjša mokrišča, ko ocenjujemo biodiverzitetno vrednost teh površin. Tu bi morali razglasiti ti. rnikro-rezervate in strogo določene naravne rezervate (n.pr. osamljeni otočki s kolonijami gnezdečih ptic ali votline v obalnem morju, kjer domuje medvedjica, ali pa npr. značilni vaški kali in presihajoče mlake v slovenskem sub-mediteranskem in kraškem pasu). Treba je jasno povedati, da v strogo določenih naravnih rezervatih ni mogoča nobena vrsta turizma in da je turizem močno vprašljiv tudi v narodnih parkih. Tudi druge spremembe namembnosti teh površin so nedopustne. Si. 2: Strme prepadne stene nad morjem na otoku Cresu nudijo gnezdilno nišo koloniji beloglavih jastrebov Gyps fulvus. (Foto: L Škornik) Fig. 2: Steep walls above the sea surface offer an excelent breeding site for the colony of Griffon Vulture Gyps fulvus on the island ofCres. (Photo: I. Škornik) Država Ste v 11 o Štev i lo Število rastlin- prostoži- endemičnih vrst skih vrst po 2. večih vrst (vrst, ki jih aneksu smernic drugod ni) EU o habitatih Grčija 4992 742 36 Italija 5598 712 45 Španija 4916 941 87 Poljska 2300 3 ni članica EU Danska 1252 1 3 irska 950 0 ■ 0 90 ANNALES • Ser. hist. nat. • 11 2001 • 1 (23) Andrej SOVINC: ZAVAROVANA OBMOČJA KOT ORODJE ZA OHRANJANJE BIODIVERZITETF V SREDOZEMLJU, 87-92 Naslednji primer nesprejemljive dejavnosti v narodnih parkih in strogo določenih naravnih rezervatih je lov, ki ga pogosto promovirajo kot del turističnih dejavnosti. Močni lovski lobiji v Franciji, Italiji, Grčiji in Španiji pogosto nasprotujejo ustanavljanju novih parkov, hkrati pa lovci nadaljujejo s svojim početjem znotraj nekaterih obstoječih regionalnih parkov. Morsko okolje je vsaj delno obravnavano v ram-sarski definiciji mokrišč. Morskih zavarovanih območij je premalo in v večini sredozemskih držav z njimi sploh ne upravljajo. Predpis Barcelonske konvencije o posebno zavarovanih območjih določa nekakšen glavni mednarodni okvir za ustanavljanje morskih zavarovanih območij v Sredozemlju. Uresničevanje tega predpisa podpira Regionalni center za posebno zavarovana območja (RAC/SPA), ki je del tako imenovanega Sredozemskega akcijskega načrta in ima sedež v Tunisu. Podpora prihaja tudi iz Mreže sredozemskih zavarovanih območij (MED PA N), ki je pod zaščito Svetovne banke in dobiva podporo od Programa za sredozemsko okoljsko tehnično pomoč (METAP). ZAKLJUČKI IN PRIPOROČILA Zavarovana območja so po splošnem mnenju eno najučinkovitejših sredstev za ohranjanje biodiver-zitete in situ; - Sredozemlje je tako imenovana "vroča točka" bio-diverzitete, ki pa je ne moremo ohraniti brez nadaljnje zaščite v sklopu zavarovanih območij; Cilji, kot so navedeni v Strategiji za pravno zaščito vseh sredozemskih mokrišč (MedWet and Convention on VVetlands, 1998), so opisani tudi v "Parkih za življenje", prvem akcijskem načrtu za zavarovana območja v Evropi; Čeprav je bil turizem označen kot poglavitna grožnja biodiverzitetnim vrednotam v Sredozemlju, je treba vendarle reči, da sta turizem in naravovarstvo pogosto lahko združljiva in medsebojno koristna, toda le v primeru, če ti dejavnosti opravljamo so-naravno in v za to primernih območjih; Kar največ preostalih sredozemskih naravnih ali naravni podobnih območij je treba zavarovati po merilih IUCN (1. in 2. kategorija upravljanja zavarovanih območij; strogo določeni naravni rezervati in narodni parki), kjer je turizem bodisi strogo omejen in nadzorovan ali pa sploh ni dovoljen; Mikrorezervati se zdijo še posebej pomembni za ohranjanje manjših sredozemskih mokrišč in drugih habitatov; Morskih zavarovanih območij je premalo, in ker v večini sredozemskih držav zanje niso pripravljeni načrti upravljanja, je treba na tem področju nujno ukrepati; Vsako zavarovano območje bi moralo imeti svoj enotni upravljalski načrt. Za vsako zavarovano območje bi bilo treba razviti akcijski načrt za sonaravni turizem, in sicer kot del enotnega upravljalskega načrta. PROTECTED AREAS AS AN INSTRUMENT FOR THE CONSERVATION OF BIODIVERSITY IN THE MEDITERRANEAN Andrej SOVINC Vodnogospodarski institut, Sl-t000 Ljubljana, Hajdrihova 28c E-mail: andrej.sovine@guest'.arnes.si SUMMARY In view of the loss of many wetlands in the Mediterranean countries during the last few decades and due to the increasing demands by tourism and other pressures exerted on nature through physical planning it is becoming clear that conservation of biodiversity in the Mediterranean, particularly in wetlands and coastal areas, will not be possible merely with sustainable use of resources. The author calls our attention to the fact that protected areas are one of the most effective means for the conservation of biodiversity\n situ. Key words: protected areas, biodiversity, nature conservation, the Mediterranean 91 ANNALES • Ser. hist. nat. ■ 11 - 2001 • 1 (23) Andrej SOV5NC: ZAVAROVANA OBMOČJA KOT ORODJE ZA OHRANJANJE BIODIVERZJTETE V SREDOZEMLJU, 87-92 LITE RATURA lUCN (1994): Parks for Life: Action for Protected Areas in Europe. Gland, Switzerland. MedWet and Convention on Wetlands (1998): A Strategy for Mediterranean Wetlands. Thessaloniki, Greece. Skoberne, P. (1997): Pregled mednarodnih organizacij in predpisov s področja varstva narave. Uprava za varstvo narave, Ministrstvu za okolje in prostor, Ljubljana. Sovine, A. (1999): Ratnsarska konvencija in slovenska mokrišča. Nacionalni odbor RS za Ramsarsko konvencijo, Ljubljana, VVCMC (1994): Guidelines for Protected Area Management Categories. Cambridge, UK. 92 ANNAUES • Ser. hist. nat. -11 • 2001 1 (23) strokovni članek UDK 502.6:556.36 prejeto: 10.4.2001 POKRAJINSKA OGROŽENOST IN UKREPi ZA ZAŠČITO KRAŠKEGA IZVIRA BISTRICA Gregor KOVAČIČ SI-6250 ilirska Bistrica, Maistrova 18 E-mai!: gregor.a.kovacic@kiss.urii-lj.si IZVLEČEK Avtor je i' prispevku ugotavljal, kakšna je pokrajinska ogroženost kraškega izvira Bistrica, ter podal predlog zaščitnih ukrepov za njegovo zavarovanje. Vodovarstveni ukrepi obsegajo sanacijo spodnjega kamnoloma in športnega strelišča na Črnih njivah, komunalno ureditev turističnega naselja Sviščaki ter ureditev cestnega omrežja ^ njegovem zaledju. Obenem je treba za zagotavljanje zdravstvene ustreznosti izvira organizirati učinkovit nadzor nad uresničevanjem preventivnih zaščitnih ukrepov v gradbeni, gozdarski in kmetijski dejavnosti. Ključne besede: pokrajinska ogroženost, kraški izvir Bistrica, vodovarstveni ukrepi, vodovarstvena območja VULNERABSLÍTÁ AMBIENTALE DELLA SORGENTE CARSICA BISTRICA E POSSiBiLI MISURE DI PROTEZÍONE SlNTESl L'autore esamina la vulnerabilitá ambiéntalo della sorgente carsica Bistrica e propone una serie di misure di protezione e mantenimento. Tali misure includono il rísanamento della cava inferióte e del polígono di tiro sportivo Črne njive, nonché adeguate misure ¡gienico-sanitarie al villaggio turístico di Sviščaki e la regolazione del sistema stradale verso l'entroterra. L 'autore sottolinea la neccessitá di uno stretto controllo delle attivítá ediiizie, forestali e agricolturali, al fine di assicurare un 'appropríata quaiítk dell'acqua potabih proveniente dalla sorgente. Parole cliiave: vulnerabilitá ambiéntale, sorgente carsica Bistrica, misure di protezione deíla sorgente idrica 93 ANNALES Ser. hist. nat. • 11 • 2001 • 1 (23) Gregor KOVAČIČ; POKRAJINSKA OGROŽENOST IN UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA BtSTRICA, 93-10-1 UVOD Za oskrbo s pitno vodo v Sloveniji so zeio pomembni obsežni kraški vodonosniki, ki so pomembna zaloga pitne vode. Vendar so kraška območja z vidika varovanja vode zelo problematična, saj se negativni vplivi zaradi slabe filtracije in relativno hitrega in zapletenega podzemeljskega toka lahko dolgo kažejo na kakovosti pitne vode. Razmere na teh območjih je moč obvladovati le z dolgoročnimi, pretežno preventivnimi ukrepi, ki so usmerjeni v selekcioniranje človekovih dejavnosti, sprejemljivih v tem prostoru, in z doslednim uresničevanjem preventivnih zaščitnih ukrepov. V Sloveniji kraški izviri pokrivajo približno 43% potreb po pitni vodi (Plut, 2000), pomembni pa so tudi za oskrbo občine Ilirska Bistrica. Eden pomembnejših kraških izvirov v Sloveniji, zlasti pa na območju jugozahodne Slovenije, je kraški izvir Bistrica (Brumen et al., 1991), ki s pitno vodo oskrbuje pretežni del občine Ilirska Bistrica, nekaj naselij v občini Hrpelje-Kozina ter del Kvarnerja. Vsi viri pitne vode v občini Ilirska Bistrica (30 virov pitne vode v občini) so zavarovani z Odlokom o določitvi varstvenih pasov in ukrepov za zavarovanje vodnih virov (PN Uradne objave, 39/1985), vendar pa vodovarstveni pasovi niso izdelani na podlagi predhodnih hidrogeoloških raziskav hidrogeografskih zaledij posameznih virov pitne vode. Tako so vodovarstvena območja določena le na osnovi razdalj od zajetij, režim varovanja pa je v primerjavi z obstoječimi, novejšimi metodologijami o zavarovanju podzemne pitne vode preblago in slabo definiran. Na podlagi hidrogeoloških raziskav zaledja kraškega izvira Bistrica, ki jih je Geološki zavod Ljubljana opravil v letu 1989 ({uren & Krivic, 1989), so bile izdelane strokovne podlage za njegovo zavarovanje. Osnove za določitev vodovarstveni h pasov in območij so bile v omenjeni študiji litološka zgradba terena, površinske in podzemske razvodnice, tektonika in hidrogeološke karakteristike ozemlja. Hidrogeografsko zaledje kraškega izvira Bistrica je tako razdeljeno na štiri vodovarstvene pasove, ki skupaj obsegajo prek 95 km2 ozemlja (SI. 1), določen pa je tudi vodovarstveni režim, ki bi se v posameznih pasovih zaščite moral uresničevati. Varstveni pasovi so bili izdelani na podlagi obstoječih podatkov, kar zaradi specifičnosti kraškega terena ne zadostuje. Upoštevali so hidrogeografski (površinske ra- \ V h. H -M:' -Ir1 •--•.. // K. ^ iutotcAv, X .i.;: % ..._ LEGENDA |_| f. vodovarstvena cona II. vodovarstvena cona III. vodovarstvena cona IV. vodovarstvena cona ^V. ' =• . ■ POT, ONESNAŽEVALCI I - Spodiiji kamnolom H- ,, _ 2 - Strelišče Črt« njive ^ . " N^-jUS"* f'' 3 - Kamnolom Gahrm-ecr'^. ■ -' X ^«i. J^ ■ 4-TurisSino naselje ^"T^""" ^ .....^'"^mmce \ S vi Ščaki j; S - Mrakova jama ii^ Cuimim'A- . i-.'t, .i Tzdelai: Gregor FCovafiič - PodtaKa: Predcdna karia obilne litrska Bistrica, 1981 SI. 1: Vodovarstveni pasovi kraškega izvira Bistrica in njegovi potencialni onesnaževalci. (Juren & Krivic, 1989) Fig. 1: The water-protection areas of the Bistrica karst spring and its potential pollutants, (/uren & Krivic, 1989) 94 ANNALES • Ser. hist nat. 11- 2001 1 (23) Gregor KOVAČIČ: POKRAJINSKA OGROŽENOST IN UKREP! ZA ZAŠČITO KRAŠKEGA tZViRA GISTRICA, 93-1 CM zvodnice), hidrogeološki (podzemske razvodnice), lito-loški (kolektorji-prepustne plasti: apnenci, dolomiti; izolatorji-nepropustne snovi: fliš) in hidrodinamični kriterij (hitrost pretoka vode od potencialnega mesta onesnaževanja do izvira in čas zadrževanja vode v podzemlju z ozirom na samočistilne sposobnosti in eventualno možnost posredovanja v primeru nesreče z izlitjem škodljivih snovi). Točnost podzemnih poti bi morali potrditi s sledilnimi poskusi ali pa z merjenjem piezometrične gladine kraške talne vode v globokem krasu Snežniške planote. Obe metodi nam omogočata določitev podzemnih vodnih povezav, smeri in hitrost odtoka padavinske vode v notranjosti dobro razvitega kraškega vodonosnega sistema (Ford & VViifiams, 1992). Na osnovi hidrogeoloških raziskav (juren & Krivic, 1989) je bil na pobudo Komunalno stanovanjskega podjetja Ilirska Bistrica, ki je upravljalec omenjenega izvira, izdelan predlog o zaščiti kraškega izvira Bistrica (KSP ilirska Bistrica, 1995), ki pa do danes še ni bil sprejet z občinskim odlokom. Zaščitni ukrepi se ne uresničujejo, kar pomeni, da je regionalno pomembni vir pitne vode praktično nezavarovan. HIDROGEOLOŠKE ZNAČILNOSTI OBMOČJA Hidrogeografsko zaledje kraškega izvira Bistrica leži v celoti na območju Snežniške planote, ki se v strmi stopnji dviga iznad doline Reke. Obseg celotnega vodo-varstvenega območja in posameznih con zaščite izvira Bistrica prikazuje slika 1. Na severu poteka hidro-geografska meja po stari razvodnici med Pivko in Reko, ki se je izoblikovala že v pliocenu. Ta poteka od naselja Knežak proti vzhodu po vrhovih Milanka (948 m.n.v.), Velika Milanja (1099 m.n.v.) do javorja (1065 m.n.v.) (Melik, 1951). Danes markantno sleme ponazarja mejo med zunanjimi vodovarstvenimi pasovi izvira Bistrica ter vrtin K-1 in K-3 pri Knežaku. Na omenjenem območju prihaja do bifurkacije, saj nizke vode v glavnem odtekajo v izvir Bistrica, visoke vode pa odtekajo proti Pivki (Habič, 1984). Na severozahodu širše vodovarst-veno območje izvira Bistrica meji na širši varstveni pas kraškega izvira Podstenjšek, Na jugu poteka meja vodo-varstvenega območja po narivnem robu, pod katerim izvirajo Številni manjši izviri, zajeti za vodno oskrbo prebivalcev Podgore. Vodooskrbna območja izvirov v Podgori se prepletajo med seboj ter s bidrogeografskim zaledjem kraškega izvira Bistrica. Nejasna je meja IV. vodovarstvene cone zaščite kraškega izvira Bistrica, ki so jo zaradi slabšega poznavanja terena in da bi se izognili morebitnim nepremišljenim posegom v naravo, pomaknili do roba dinarskega preloma, kjer so opazne vidne geološke spremembe terena (jurefi & Krivic, 1989). Snežniška planota pripada hidrološkemu tipu globokega raztočnega krasa in je najpomembnejše vodo- oskrbna ter hkrati vodovarstveno območje v občini Ilirska Bistrica, saj zbira padavi nsko vodo za zajetja Bistrica, Podstenjšek, vrtini K-1 in K-3 (Knežak) ter več manjših lokalnih zajetij v Podgori in izvirkov nad Knežakom. Za ta tip krasa je pomembna avtohtona padavinska voda, ki prenika v kraško podzemlje in odteka v različne smeri proti kraškim izvirom na obrobju. Snežniška planota je razvodno območje, saj se njen jugovzhodni del odmaka v porečje Riječine (Hrvaška), severovzhodni del pripada črnomorskemu povodju, zahodni predeli pa napajajo kraške izvire, ki prihajajo na dan ob stiku s flišem in so sestavni del porečja Reke (SI. 2). Snežniško planoto gradijo pretežno apnenci, dolomiti, apnenčaste in dolomitne breče jurske in kred-ne starosti, tu in tam pa se v majhnem obsegu pojavljajo tudi ledeniške morene in aluvialne naplavine (Šikič ef al., 1972; Šikič & Pleničar, 1975). Kredne plasti snežniškega masiva so na zahodu narinjene prek flišnih plasti brkinske sinklinale, kar dokazujeta flišnati tektonski okni pri Zagorju in Knežaku, ki sta se pokazali potem, ko je vodna erozija odstranita del apnenca, ki je prekrival spodaj ležeči fliš (Pleničar, 1968). Nariv je jasno izražen v markantni stopnji nad zgornjim tokom Reke v Podgori. Za določitev padavinskega zaledja in nivoja napajalnega območja so zanimivi kaverozno-razpoklinski ter dobro in srednje prepustni kredni in paleogenski apnenci, dolomiti ter breče, ki so tektonsko zelo pretrti, kar še povečuje njihovo propustnost. Tektonika je lahko razlog za razvoj podzemnih poti, lahko pa deluje kot bariera podzemni vodi, če so tektonske cone miloni-tizirane (na območju dolomita). Omenjene kamnine se razprostirajo severovzhodno od izvira Bistrica, ki je na najnižji točki kontakta nepropustnih plasti fliša in apnenca. Padavinsko in vodooskrbno območje, polno vrtač, dolin in brezen, sega do dinarskega preloma, ki meji na apnence in debelokristalaste dolomite jurske starosti. Manjše predele prekrivajo tudi usedline z medzrnsko poroznostjo in srednjo stopnjo izdatnosti in tranzmisivnosti, ki se pojavljajo v okolici počitniškega naselja Sviščaki, v Črni dragi in v Črnem dolu. Gre za pesek in slabo zaobljen prod ledeniških moren črno-dolskega ledenika, ki se je v ledeni dobi raztezal od vrha Snežnika proti zahodu (Šifrer, 1959). Od preloma dalje vode gravitirajo že proti Kvarnerju, zaledju reke Pivke in Cerkniškemu jezeru, ki sodita k porečju Ljubljanice (juren & Krivic, 1989; Pavlovec & Pleničar, 1980; Šikič et al., 1972; Šikič & Pleničar, 1975). Vodooskrbno območje označuje razvit globoki kras Snežniške planote z dobro prepustnostjo, kar pomeni, da se kraška talna voda v notranjosti pretaka zelo hitro, čeprav so hitrosti v prežeti coni zelo majhne in znašajo le nekaj cm/s. Posledica pretakanja po kanalih je, da skorajda ne prihaja do mehaničnega čiščenja, saj so pretoki kraške podzemne vode v primerjavi z nekraš-kimi podzemskimi zelo hitri in skrajšajo čas že tako 95 ANNALES • Ser. hist. nat. - 11 2001 • 1 (23) Gregor KOVAČIČ: POKRAJINSKA OGROŽENOST iN UKREPI 2A ZAŠČITO KRAŠKEGA IZVIRA BISTRICA, 93-1M o o ° ■o °o 72 O?- Pl Aluvialne naplavine (tranzntisiviiost in izdatnost dobra) - Q Po bočni «niši (tranzmisivnost in izdatnost zelo dobra) - Q Lcdeni.šfu nanosi (srednja stopnja tranzmisivnosti in izdatnosti) - Q Glina, pesek, plasti lignita (zelo slaba prepustnost) FliŠ; menjavanje glinovcev, laporoveev in peščenjaka (tranzmisivnost in izdatnost od zelo slabe do srednje) Foramcnifcrski apnenec (srednja prepustnost) - Pg nn n H S Svetlo sivi apnenci ju debelokristalašti dolomiti (dobra prepustnost) - K Apnenci in dolomiti (srednja do dobra prepustnost) Apnenci, dolomiti, apnenčaste in apnenčasto tlolomilue hi-eče (srednja prepustnost) Plastoviti apnence, dolomiti, apnenčasto doloraitna brcfa (srednja prepustnost) Svetlo sivi apnenec (dobra prepustnost) Meja vodovarstvenega območja kr. izvira Bistrica SI. 2; Geološke in hidrogeološke značilnosti območja (povzel in priredil po Šikič et al., 1972; Šikič & Pleničar, 1975; Pavlovec & Pleničar, 1980;Juren & Krivic, 1989). Fig. 2: Geological and hidrogeologtcal characteristics of the region (based on Šikič et ai, 1972; Šikič & Pleničar, 1975; Pavlovec & Pleničar, 1980; {uren & Krivic, 1989). omejenega biokemijskega čiščenja, kar slabša njeno kakovost. Hidrogeografsko zaledje kraških virov pitne vode je tako zaradi velike prepustnosti tal in omejenega naravnega čiščenja zelo izpostavljeno onesnaženju in močno pokrajinsko občutljivo (Pord & VVilliams, 1992; Plut, 1998; Šušteršič, 1992). METEOROLOŠKE ZNAČILNOSTI OBMOČJA Podatki o padavinah za meteorološko postajo Ilirska Bistrica (414 m.n.v.) kanejo, da letno v dolinskem območju pade 1448 mm padavin. Proti vzhodu padavine zaradi orografske pregrade naraščajo ter na zahodnem 96 ANNALES • Ser. hist. nat. -11- 2001 • 1 (23) Gregor KOVAČIČ: POKRAJINSKA OGROŽENOST IN UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA BISTRICA, 93- robu Snežniške planote presežejo 1800 mrn. Podatki za Mašun (1022 m.n.v.; 2041 mm/letno) in bolj južno ležeče Gomance (924 m.n.v.; 2738 mm/letno) kažejo, da se količina padavin proti vršnim predelom Snežniške planote še veča in doseže približno 2500 mm, na najvišjih predelih pa celo 3000 mm. Snežniška planota je dobro namočena, kar je z vidika oskrbe s pitno vodo zelo ugodno (Zupančič, 1995, 1998). Povprečna letna / januarska / julijska temperatura zraka na meteorološki postaji Ilirska Bistrica znaša 9,6°C / 0,8°C / 18,7°C. Temperature se od roba Snežniške planote proti notranjosti nižajo, kar se da sklepati iz podatkov meteoroloških postaj Gomance in Mašun. Povprečna letna / januarska / julijska temperatura zraka na Comancah znaša 6,7°C / -1,5°C / 15,6°C, na Mašunu pa 5,6°C / -3,1°C / 14,6°C. Proti vršnim delom planote se temperature še znižajo, kjer znašajo okrog 2°C / -6°C / 10QC (Kiernenčič, 1959; Mekinda-Majaron, 1995). Vodooskrbno območje kraškega izvira Bistrica v celoti leži na območju Snežniške planote, kjer je zaradi večje nadmorske višine in posledično nižjih temperatur izhlapevanje manjše, prepustna karbonatna litološka podlaga pa omogoča hitro prenikanje vode v globino, kar tudi zmanjšuje možnost izhlapevanja, povečuje pa vodni odtok. MATERIALI IN METODE S pomočjo podatkov o kakovosti kraškega izvira Bistrica, ki sern jih pridobil na ZZV Koper (Zavod za zdravstveno varstvo Koper), ter tehničnih podatkov o zajetju izvira, ki sem jih dobil na KSP Ilirska Bistrica, sern ugotavljal pokrajinske značilnosti omenjenega vodnega vira. S terenskim pregledom hidrogeografskega zaledja v letih 1999 in 2000 sem evidentiral potencialne onesnaževalce v zaledju ter skušal ugotoviti stopnjo njihovega ogrožanja in obremenjevanja kraškega izvira Bistrica, pri čemer sem dognanja s terena primerjal z rezultati analiz kakovosti pitne vode na zajetju. Zaradi upoštevanja dejstva, da se pri varovanju pitne vode srečujemo tako s časovno kot tudi stroškovno komponento, sem temu primerno predlagane sanacijske in preventivne ukrepe za zaščito kraškega izvira Bistrica tudi časovno uvrstil glede na nujnost izvedbe. Pri tem sem upošteval čas pretoka podzemne kraške vode oziroma hitrost širjenja onesnaževala do zajetja (definirano z vodovarstvenimi pasovi) in potencialno nevarnost posameznega vira onesnaženja za omenjeno zajetje. Pri določanju ukrepov za zaščito sem izhajal iz vodovarstvenih ukrepov v posameznih vodovarstvenlh conah, ki jih določa Pravilnik za določevanje vodovarstvenih območij podzemnih vodnih virov (Petauer & Veselič, 1997b, v nadaljnjem besedilu Pravilnik). POKRAJINSKE ZNAČILNOSTI KRAŠKEGA IZVIRA BISTRICA Reka Bistrica izvira neposredno nad starim delom mesta ilirska Bistrica in se komaj po kilometru površin-^ skega toka 2e izliva v reko Reko ter je njen stalen desni pritok. Bistrica izvira v manjši zatrepni dolini, voda priteka na dan ob stiku apnenca in fliša v nadmorski višini 420 metrov. Glede na izvor je voda podzemna, zbira pa se v vodonosniku s kraško poroznostjo. Izvir je zajet za vodno oskrbo. Kapaciteta izvira je 200,60 l/s, vendar je zaradi biološkega minimuma moč izkoristiti le 150,60 l/s. Voda priteka po približno 90 metrov dolgem tunelu do zidanega zajetja, od tod pa v čistilno napravo. Čistilna naprava je sestavljena iz dveh usedalnikov za posedanje grobih delcev umazanije, kjer se za pospešitev koagulacije po potrebi dodaja aluminijev sulfat. Sestavni del sta tudi dva peščena filtra z zmogljivostjo prečišče-vanja kakih 74 l/s, kolikor je trenutni odvzem na zajetju. Voda priteka v čistilno napravo prosto, kar pomeni, da potem, ko nivo vode upade, voda ne priteka več v čistilni filter, temveč prek dezinfekcije (plinski klor) neposredno v omrežja posameznih vodovodnih sistemov občinskega vodovoda Ilirska Bistrica (KSP Ilirska Bistrica, 2000). Nižinski vodovod (sistem "A") s pitno vodo oskrbuje območje Podgore, Brkinski vodovod (sistem "B") naselja v Brkinih, vodovod Visoki kras (sistem "C") območje Podgrajskega in Jelšanskega podolja ter Brda, sistem "D" pa mesto Ilirska Bistrica in naselja v njegovi bližini (Tab. 1). V obdobju, ko vode v lokalnih virih primanjkuje, oskrbuje vodovod Ilirska Bistrica s pitno vodo 12038 (84,6%) prebivalcev občine Ilirska Bistrica. Večji del leta oskrba iz lokalnih vodnih virov zadostuje in takrat se iz vodovoda Ilirska Bistrica oskrbuje 10548 (74,2%) prebivalcev občine. Vodovod Ilirska Bistrica ni pomemben samo z vidika oskrbe s pitno vodo v občini Ilirska Bistrica, saj se iz njega oskrbujejo tudi naselja zunaj meja občine. Do leta 1990 (pred priključitvijo na Kraški vodovod) se je z bistriško vodo oskrbovala večina naselij v podolju od Obrova do Kozine (območje občine Hrpelje-Kozrna), po letu 1997 pa samo še naselja Ob-rov, javorje, Tatre in Brezovo Brdo. Kraški izvir Bistrica je pomemben tudi za oskrbo sosednje Hrvaške. Po podatkih KSP Ilirska Bistrica se približno 40% načrpane vode iz zajetja Bistrica dovaja na ozemlje sosednje Hrvaške, kjer se z bistriško vodo oskrbujejo naselja v trikotniku od mejnega prehoda Rupa, Klane do naselja Matulji. Izgube na celotnem omrežju so velike in po ocenah znašajo od 35 do 45% (KSP Ilirska Bistrica, 2000; Občina Ilirska Bistrica, 2000). 97 ANNALES • Ser. hist nat. ■ 11 ■ 2001 • 1 (23) Gregor KOVAČ!C: POKRAJINSKA OGROŽENOST in UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA BISTRICA, 93-104 Tab. /* Vodovodni sistemi vodovoda Ilirska Bistrica (KSP Ilirska Bistrica, 2000). Tab. 1: Water-supply systems of the Ilirska Bistrica aqueduct (KSP Ilirska Bistrica, 2000). Sistemi vodovoda Ilirska Bistrica Naselja v občini Ilirska Bistrica, ki se stalno oskrbujejo iz sistem a Naselja v občini Ilirska Bistrica, ki se občasno oskrbujejo iz sistema Nižinski vodovod -sistem "A" jasen Vrbovo, Vrbica, Kuteževo, Podgraje, Zabiče Brkinski vodovod -sistem "B" Dobropolje, Zarečica, Zarečje, Marije, V. Bukovica, Soze, Tominje, Brce, Smrje, Prem, G. Bitnja, S. Bitnja, Kilovče, Ratečevo Brdo, Zajetje, Pregarje, Huje, Gabrk, Rjavče, Prelože, Ostrožno Brdo, janeževo Brdo, Čelje Vodovod Visoki kras - sistem "C" Studena gora, Pavlica, Sabonje, V. Brdo, Starod, Račice, Podgrad, Podbeže, Hrušica, M. Loče, Jelšane, Nova vas Dolenje, Novokračine Vodovod Bistrica -sistem "D" Ilirska Bistrica, Topole, Rečica, D. Zemon, G. Zernon, M. Bukovica, zaselek Zemonska vaga Eizikalno-kemijska kakovost surove vode izvira je ze!o visoka, saj zadnjih sedem let ne beležijo zdravstveno neustreznega vzorca. Nekoliko slabša je na vodovodnem omrežju, kar opozarja na zastarelo oziroma neustrezno napeljavo na posameznih odsekih vodovoda Ilirska Bistrica. Rezultati mikrobioloških analiz surove vode kažejo, da je bilo v zadnjih treh letih od 20 do 50% analiz zdravstveno neustreznih {SI. 3). Vzrok zdravstvene neustreznosti surove vode so povečani Escherichia coli, presežen MPN skupnih koliformnih bakterij, preseženo število bakterij pri 22°C in pri 37°C. Po obdelavi v čistilni napravi (filtracija, dezinfekcija) postane voda mikrobiološko ustrezna (SI. 4). Zaradi slabo grajenega omrežja na določenih odsekih vodovoda se enkrat do dvakrat letno na njem ugotovijo povečani Escherichia coli, presežen MPN skupnih koliformnih bakterij ter preseženo število bakterij pri 22°C (ZZV Koper, 2000). ^mikrobiološke analize pil ne — pljzikaino-kemijske analize pilne \od© — ......- — "i 108B 1987 19BS 1930 1990 1991 1982 1953 19B4 199S 1996 1997 1999 1998 teto vzorčenja SI. 3: Rezultati mikrobioloških in fizikalno-kemijskih analiz pitne vode na vodovodu Ilirska Bistrica (ZZV Koper, 2000). Fig. 3: The results of the microbiological and physical-chemical analyses of drinking-water samples taken from the Ilirska Bistrica water-supply system (ZZV Koper, 2000). 1986 1987 1988 1989 1990 1991 1392 1993 1994 199S 139S 1397 199S 199S Leto vsoretmja SI. 4: Rezultati mikrobioloških analiz kraškega izvira Bistrica na zajetju in po obdelavi v čistilni napravi (ZZV Koper, 2000). Fig. 4: The results of the microbiological analyses of drinking-water samples taken from the spring and after its treatment (ZZV Koper, 2000). Pomen izvira z vidika oskrbe s pitno vodo je velik, saj ni moč najti primerno izdatnega vira pitne vode, ki bi v primeru kontaminacije izvira lahko nadomestil potrebe po pitni vodi na tem območju. Njegov pomen povečuje dejstvo, da s pitno vodo oskrbuje območja zunaj ozemlja občine ilirska Bistrica in tudi države, izvir je hkrati pomembna rezerva pri oskrbi s pitno vodo, saj je moč izkoristiti Še enkrat toliko vode, kot se je trenutno dovaja v omrežje, zadovoljiva pa je tudi njegova mikrobiološka in fizikalno-kemijska kakovost. POKRAJINSKA OGROŽENOST KRAŠKEGA IZVIRA BISTRICA Z vidika varstva pitne vode je pozitivno to, da hidrogeografsko zaledje kraškega izvira Bistrica sestavljajo obsežni in neposeljeni gozdovi Snežniške planote, 98 ANNALES • Ser. hist. nai. -11 2001 • 1 (23) Gregor KOVAČIČ: POKRAJINSKA 0GR0ŽEN05T IN UKREPI ZA ZAŠČITO KRAŠKEGA 1ZV)RA BISTRICA, 93-104 kljub temu pa je vodni vir ogrožen zaradi gozdarske, gradbeniške in turistične dejavnosti v njegovem o2jem in širšem zaledju. Spodnji kamnolom in kamnolom Gabrovec Samočistilne sposobnosti kraških vodonosnih sistemov so zelo skromne tudi zaradi tanke preperelinske odeje, ki pokriva ozemlje s karbonatno kamninsko podlago. Še tako skromna plast prsti pa pomeni dober filter za padavinsko vodo in tam, kjer je ta odstranjena, kot na primer v cestnih usekih in kamnolomih, lahko onesnaženje brez čiščenja hitro prodre v globino in potuje proti izvirom. Pri kamnolomih je treba biti posebno previden z vplivom na neposredni kraški odtok, kar pomeni, da je treba skrbno paziti na preprečevanje izlivov nafte in olj ter drugih strupenih ali škodljivih snovi, saj bi vsakršno njihovo izlitje lahko daljnosežno vplivalo na kvaliteto kraške talne vode (Šebela, 1997). Na vodooskrbnem območju izvira Bistrica imamo dva večja kamnoloma, od katerih eden ne obratuje več (Si. 1). Kamnolom apnenca Gabrovec leži približno štiri kilometre vzhodno od Ilirske Bistrice v Ni, vodovarst-venem pasu kraškega izvira Bistrica in ni urejen tako, da obratovanje ne bi ogrožalo kraške talne vode. Letna proizvodnja je približno 50-100,000 m3 (Uprava RS za varstvo narave in Nizozemsko kraljevo združenje za varstvo narave, 1999). Delovni stroji za izkop kamenja stojijo prosto na delovišču, sanacijo onesnaženja tal z oljem ali nafto iz strojev pa zaradi hitrega prenikanja v notranjost ne bi bilo mogoče opraviti v celoti. Drugi kamnolom leži mnogo bližje izvira Bistrica v II. vodo varstvenem območju, s svojimi površinami pa sega skoraj do 1, vodovarstvenega pasu. Kamnolom apnenca je sicer opuščen, vendar ni saniran. Iz kamnoloma Gabrovec vanj vozijo kamenje, kjer ga predelujejo v pesek. Kamnolom je hkrati parkirišče za več delovnih strojev in težkih tovornjakov za prevoz kamenja. V kamnolomu je odloženih tudi nekaj starih in neuporabnih delovnih strojev, avtomobilov in tovornjakov, ki ogrožajo kakovost pitne vode v izviru Bistrica, V kamnolomu je tudi neurejeno in slabo zavarovano skladišče naftnih derivatov za potrebe delovnih strojev in tovornjakov. Nafta je skladiščena v sodih, podlaga ni vodotesna, morebitno izlitje nafte bi imelo velike posledice za zajetje Bistrica, saj bi bil udor nafte v podzemlje zaradi dobro propustne podlage zelo hiter. Slabo leto dni kamnolom uporabljajo kot odlagališče gradbenega materiala za širše območje ilirske Bistrice. Odlaganje trdnih netopnih snovi z vidika varstva kraške talne vode ni problematično, vendar se nadzor nad sestavo odpadnega gradbenega materiala ne opravlja, tako da med odpadnim gradbenim materialom najdemo tudi številne nevarne odpadke, kot so ostanki embalaže različnih zaščitnih sredstev (barve, laki), avtomobilske gume, salonitne plošče in drugo. Zaradi karbonatne podlage, ki ni zaščitena s tankim slojem prsti, lahko te snovi hitro prodrejo v globino in izvir Bistrica za dalj časa onesnažijo. Strelišče na Črnih njivah Na delu nekdanjega vojaškega strelišča, ki leži v III. vodo varstvenem pasu izvira Bistrica, v neposredni bližini II. vodovarstvenega območja, se je po letu 1988 razvilo športno strelišče na glinaste golobe (SI. 5). Aktivna površina strelišča je v plitki vrtači, ki jo obrašča strnjen borov gozd, lega v plitki vrtači pogojuje nekoliko debelejšo plast prsti, ki je pomemben zaščitni filter za padavinsko vodo. Ta se na poti v notranjost obogati s svincem, ki ga vsebujejo šibrni naboji pušk za športno streljanje na leteče cilje - disciplino Trap. Uredba o vnosu nevarnih in rastlinskih gnojil v tla (UL RS 68/1996, v nadaljnjem besedilu Uredba) določa največji letni dovoljeni vnos svinca in njegovih spojin v tla, ki ne sme presegati 2,5 kg/ha. Posamezen naboj tehta 24 gramov, kar pomeni, da bi glede na velikost strelišča, ki pokriva nekaj več kot 2 ha, že 200 izstreljenih nabojev letno pomenilo doseženo mejno vrednost letnega vnosa SI. 5: Trap-športno strelišče v zaledju izvira Bistrica. (Foto: G. Kovačič) Fig. 5: Trap-shooting ground in the background of the Bistrica spring. (Photo: G. Kovačič) 99 ANNALES - Ser. hrst. nat. • 11 • 2001 -1 (23) Gregor KOVAČiČ: POKRAJINSKA 0GR0ŽEN05T IN UKREP! ZA ZAŠČITO KRAŠKEGA IZVIRA BISTRICA, 93-104 svinca v tia, Koliko svinčenih nabojev je bilo v preteklosti izstreljenih, ni moč izračunati, vendar ocene kažejo, da mora biti koncentracija svinca v prsti in verjetno še globlje v notranjosti mnogo višja od mejnih vrednosti, ki jih določa Uredba (UL RS 68/1996). Žal pa se nikoli niso ugotavljale analize vsebnosti svinca v prsti na območju strelišča, ki bi te domneve potrdile. Dosedanje fizikalno-kemijske analize kakovosti vode iz izvira Bistrica tudi ne kažejo na povečano vsebnost svinca v pitni vodi, kar pa ne pomeni, da kontaminacije z njim v prihodnosti ne bo. Svinec je zdravju izredno škodljiva težka kovina, ki se spira zelo počasi. Veliko večje površine je zavzemalo vojaško strelišče, ki je danes že zelo zaraščeno, o količinah vnesenega bakra in svinca v plitko kraško prst pa lahko samo ugibamo. Turistično naselje Sviščaki Na Snežniški planoti ni naselja s stalno živečim prebivalstvom, vendar na območju, ki je hidrogeografsko zaledje kraškega izvira Bistrica, so številne planinske in druge koče (prek 20 različnih objektov) ter turistično naselje Sviščaki, ki leži v IV., torej vplivnem vodo-varstvenem pasu. Sviščaki so priljubljena izletniška točka in smučarsko rekreacijski center, so pa tudi najpogostejše izhodišče za vzpon na Snežnik. Naselje obsega prek 90 počitniških hišic (Občina Ilirska Bistrica, 2000), mnoge med njimi so zgrajene brez greznic, vprašljiva je tudi vodotesnost greznic pri drugih objektih. Glede na to, da naselje leži na vodooskrbnem območju, bi moralo imeti urejeno kanalizacijo s čistilno napravo. Promet Hidrogeografsko zaledje izvira Bistrica je prepredeno s številnimi gozdnimi cestami in vlakami, najpomembnejša pa je cestna povezava od Ilirske Bistrice do Sviščakov. Povprečno letno število vozil na dan je 96 (Gregorc, 1998). Bolj kot število je zaskrbljujoča sestava voznega parka, ki se prevaža po cesti, saj cesta pomeni edino pot za prevoz kamenja iz kamnoloma Gabrovec v spodnji kamnolom, po njej pa vozijo tudi težki tovornjaki za spravilo lesa. Meteorne vode s cestišča spirajo ostanke avtomobilskih gum, olj, ostankov izgorevanja goriv, korozijskih produktov, masti in drugih za vodo škodljivih produktov, ki neprečiščeni odtekajo v vodonosnik (Brenčič & Prestor, 1998). Glede na to, da cesta poteka v neposredni bližini I. vodovarstvenega pasu, bi bilo posledice nesreče praktično nemogoče sanirati, saj bi olje in/afi nafta iz težkih tovornjakov v zelo kratkem času dosegla izvir Bistrica in ga s tem za daljše obdobje onesnažila. Divja odlagališča odpadkov Z vidika varovanja pitne vode so zelo problematična divja odlagališča odpadkov, ki se na kraških območjih pojavljajo zlasti kot odlagališča v vrtačah in kot za-smetena brezna in jame (Šebenik, 1994). Brezna so z vodovarstvenega vidika še posebej občutljiva, saj pomenijo neposredno vodno zvezo med površjem in zapletenim sistemom vodnih kanalov v kraškem vodo-nosniku. Hidrogeografsko zaledje kraškega izvira Bistrica speleološko še ni dobro raziskano.Trenutno je edino znano onesnaženo brezno v zaledju Mrakova jama, ki leži na območju IN. vodovarstvenega pasu. Brezno je zasmeteno z raznovrstnim materialom. Kmetijska in gozdarska dejavnost Vodooskrbno območje izvira Bistrica označujejo gospodarsko pomembni obsežni jelovo-bukovi gozdovi, v nižjih legah, zlasti na območju L, II., in deloma lil. vodovarstvenega pasu, pa tudi borovi gozdovi, ki so se razvili na rendzinah in pokarbonatnih prsteh, ki so z vidika kmetijske rabe primerne le za pašno-košno rabo, usmerjeno v živinorejo (Zadnik et al, 1999). Obdelovalnih površin v napajalnem zaledju z izjemo nekaj ha travnikov ni, veliko več je pašnih površin. Na območju Goljaka nad Zabičami se v IV. vodovarstvenem pasu raztezajo obsežne pašne površine, kjer se poleti pase čreda 170 ovac. Uredba o vnosu nevarnih snovi in rastlinskih hranil v tla (UL RS 68/1996) dovoljuje rejo 3 GVŽ na 1 ha obdelovalne površine, kar pomeni, da število živali na ha obdelovalne površine na Goijaku ne presega mejnih vrednosti letnega vnosa rastlinskih hranil z živalskimi gnojili. Problematične so staje za drobnico, kjer se na gnojišču nabere veliko živalskega gnoja, ki ga deževnica počasi spira v dobro prepustna apnenčasta tla. Na območju II. vodovarstvenega pasu sta še dva manjša pašnika. Na enem se pase približno 8 GVŽ goveda, in sicer samo poleti. Na drugem veliko manjšem pašniku se čez vse leto pase približno 15 glav drobnice. Gre za ekstenzivno pašo, problematična je staja za drobnico, ki leži zelo blizu I. vodovarstvenega pasu izvira Bistrica. V okviru nastajajočega Regijskega parka Snežnik (Uprava RS -za varstvo narave in Nizozemsko kraljevo združenje za varstvo narave, 1999) je ozemlje L, II. in velikega dela lil. vodovarstvenga pasu izvira Bistrica označeno kot kmetijska krajina, v kateri naj bi se vzpodbujalo ekokmetovanje. Gozdarska dejavnost je na vodooskrbnem območju izvira Bistrica zelo intenzivna, zlasti pa v lil. in IV. vodovarstvenem območju. Z vidika ogrožanja kraške talne vode gozdarstvo ne pomeni večje nevarnosti, problematični so zlasti težka mehanizacija, namenjena spravilu in prevozu lesa, ki je največkrat parkirana kar ob gozdnih cestah po vsej Snežniški planoti, ter odvržene posode, v katerih je bila nekoč nafta, in olje za pogon motornih žag. 100 ANNALES • Ser. hist. nat. • 11 2001 • 1 (23) Gregor KOVAČIČ: POKRAJINSKA OGROŽENOST IN UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA 81STRICA, 93-104 UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA BISTIRCA Splošni varstveni ukrepi Za zavarovanje vodnega vira Bistrica pred onesnaževanjem bi morali sprejeti občinski odlok o zavarovanju, ki je bil že obravnavan na občinskem svetu, vendar ni bil sprejet. V odlok bi morali nujno vnesti nekatere spremembe (Tab. 2), zlasti pa bi bilo treba režim v vodovarstvenih pasovih prilagoditi novi metodologiji o zaščiti in varovanju podzemnih voda, ki je bila izdelana v letu 1997 za potrebe Ministrstva za okolje in prostor (Petauer & Veselic, 1997a, 1997b). Pri določanju ukrepov za zaščito vodnega vira sem izhajal iz varstvenih ukrepov v posameznih vodovarstvenih conah, ki ga določa zgoraj omenjena metodologija. Obseg posameznih vodovarstvenih con zaščite kraškega izvira Bistrica je treba sproti prilagajati novim ugotovitvam o hitrosti pretakanja kraške vode v njegovem zaledju, meje vodovarstvenih pasov pa potrditi z izvedbo sledilnih poskusov. Območje I. in II. vodovarstvenega pasu bi morali označiti s tablami, ki bi opozarjale na posebne vo-dovarstvene zahteve območja ter ljudi opominjale na nevarnost onesnaženja tako pomembnega vira pitne vode, kot je kraški izvir Bistrica. Tab, 2: Kratkoročni in dolgoročni ukrepi za zaščito kraškega izvira Bistrica. Tab■ 2: Short- and long-term measures concerning the protection of the Bistrica karst spring. Sanacija kamnolomov Za preprečitev onesnaževanja izvira Bistrica je potrebna takojšna sanacija spodnjega kamnoloma v II. vodovarstvenem pasu. Po Pravilniku (Petauer & Veselic, 1997b) v 11. vodovarstveni coni ni dovoljeno odpiranje kamnolomov, obstoječe pa je treba zapreti in sanirati. Da bi se zmanjšalo tveganje, bi morali zaradi slabega nadzora z uredbo v kamnolomu prepovedati odlaganje odpadnega gradbenega materiala, saj je njegova sestava vprašljiva oziroma bi ga morali strogo nadzorovati. Po Rismalovi metodologiji zaščite podzemnih voda iz leta 1993 (Prestor et al., 1999) je v II. vodovarstvenem pasu prepovedano odlaganje odpadnega gradbenega materiala, po metodologiji iz leta 1997 (Petauer & Veselič, 1997b) pa je dovoljeno pod pogojem, da sestava materiala ni sporna z vidika onesnaževanja pitne vode. Poleg tega bi bilo v kamnolomu treba urediti parkirne prostore za težko mehanizacijo in skladišče za nafto, tako da se prepreči prelivanje nevarnih in strupenih tekočin zunaj urejenih in vodotesnih prostorov, kot to določa Pravilnik (Petauer & Veselič, 1997b). Iz kamnoloma je treba odstraniti tudi vsa neuporabna vozila in delovne stroje. Z vodovarstvenega vidika bi bilo najboljše, če bi kamnolom zasuli in ozelenili. Vendar je treba na sanacijo gledati širše, saj je kamnolom pomemben življenjski prostor za redke vrste ptic. Tako je bil tu prvič v Sloveniji opazovan skalni berglez fS/tta neumayer) (Surina, 1999), kot verjetnega gnezdilca pa je isti avtor označil tudi redkega puščavca (Monticola solitarius). Delujoči kamnolom Gabrovec je treba sanirati do stopnje, da obratovanje kamnoloma ne bo ogrožalo kraške talne vode. Zasipavanje in ozelenitev kamnoloma z vodovarstvenega vidika nista sporna, upoštevati pa je treba redke vrste ptic, ki so si našle zatočišče v njegovem skalovju. Sanacija strelišča na Črnih njivah Da bi preprečili daljnosežne posledice dolgoletnega vnašanja svinca v občutljivo kraško notranjost na kakovost pitne vode izvira Bistrica, je potrebna sanacija športnega strelišča na Črnih njivah. Količina izstreljenih nabojev na strelišču je zelo velika, kar pomeni, da je tanka kraška prst dobro prepredena s svinčenimi šib-rami. Onesnaženo prst je treba z aktivne površine strelišča odstraniti ter jo odložiti na varen prostor zunaj vodovarstvenih območij. Območje strelišča bi nato pokrili z nepropustno folijo, čez pa nasuli novo prst. Prostor bi končno uredili tako, da meteorne vode s strelišča ne bi nekontrolirano odtekale v vodonosnik, kar bi znatno zmanjšalo potencialno nevarnost onesnaženja vodnega vira s težkimi kovinami. Popolno varnost pitne vode v izviru Bistrica bi zagotovili šele s sanacijo obstoječega strelišča ter preselitvijo strelišča na Kratkoročni ukrepi Dolgoročni ukrepi zavarovanje vodnega vira z odlokom ureditev preostalega dela ceste H. Bistrica-Sviščaki sanacija spodnjega kamnoloma graditev kanalizacijskega omrežja in čistilne naprave na Sviščakih sanacija strelišča Črne njive ureditev staj za drobnico v skladu s Strokovnim navodilom (ULSRS 10/1985) očiščenje Mrakove jame ureditev kamnoloma Gabrovec ureditev dela ceste M. 8i-strica-Sviščaki, da se prepreči odtekanje s cestišča v vodonosnik graditev neprepustnih greznic na Sviščakih namestitev opozorilnih tabel 101 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Gregor KOVAČIČ: POKRAJINSKA OGROŽENOST iN UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA BISTRICA, 93- [04 primerno lokacijo zunaj vodovarstvenih območij vodnih virov občine Ilirska Bistrica. Ureditev turističnega naselja Sviščaki Pravilnik {Petauer & Veseiič, 1997b) določa, da morajo imeti vsa naselja na vodooskrbnih območjih urejeno kanalizacijo, ter dovoljuje graditev novih objektov samo v primeru, če so ti objekti priključeni na kanalizacijsko omrežje in čistilno napravo. Za turistično naselje Sviščaki bi bila zelo primerna postavitev manjše mehansko-biološke čistilne naprave. Graditev kanalizacijskega omrežja in čistilne naprave na Sviščakih predvideva tudi Dologoročni plan občine Ilirska Bistrica za obdobje 1986 do 2000 (UL RS 7/1999). Varnost pitne vode je smiselno zagotavljati z graditvijo neprepustnih greznic in njihovim rednim čiščenjem, z nadzorom nad vodotesnostjo ter z odvozom odpadnega blata, saj do graditve čistilne naprave in kanalizacijskega omrežja še dolgo ne bo prišlo. Greznice bi morale biti urejene tako, da bi vanje odtekala le hišna odpadna voda (to je odpadna voda iz sanitarij in kuhinj), biti pa morajo tudi prezračevane. Padavinske vode ne smejo biti speljane v greznice, praznjenje in vzdrževanje greznic pa mora biti skladno s Strokovnim navodilom o urejanju gnojišč in greznic (UL SRS 10/1985, v nadaljnjem besedilu Strokovno navodilo). Ureditev cestnega omrežja Ceste v zaledju je treba urediti do stopnje, da meteorne vode s cestišča ne odtekajo neposredno v vodo-nosnik, kar je treba najprej urediti na odseku ceste Ilirska Bistrica-Sviščaki v neposredni bližini i. vodovarst-vene cone izvira Bistrica. Preostali del ceste je treba urediti tako, da se na minimum zmanjša možnost nesreč z nevarnimi snovmi, kar pomeni, da je treba omejiti hitrost vožnje, vsako razlitje pa takoj sanirati. Opozorilne table o vodovarstvenih območjih bi morali posta- viti tudi ob cesti Ilirska Bistrica-Sviščaki, ki bi voznike opozarjale na nevarnosti za vodni vir pri izlitju nevarnih snovi ob avtomobilskih nesrečah. Sanacija onesnaženega brezna Mrakova jama Se sprejemljivo količino odpadkov, to je količino, ko so izcedne vode iz odlagališča še pod neko mejo potencialnega ogrožanja kakovosti vodnega vira, je težko določiti (Šebenik, 1994). Zato je smiselna sanacija vseh divjih odlagališč odpadkov na vodooskrbnih območjih kraških izvirov. Za varovanje kakovosti pitne vode v izviru Bistrica je treba brezno Mrakova jama očistiti. Pozornost je potrebno nameniti tudi odkrivanju novih onesnaženih jam in brezen. Na podlagi pokrajinskih značilnosti divjih odlagališč odpadkov (Šebenik, 1994) lahko sklepamo, da teh ni veliko, saj so divja odlagališča odpadkov praviloma zelo blizu naselij in v bližini dostopnih poti, kjer pa ta pojav ni opazen. Ukrepi v kmetijski in gozdarski dejavnosti Na vodooskrbnem območju kraškega izvira Bistrica prevladuje ekstenzivno kmetijstvo, kar pomeni, da je v veliki meri skladno z interesi varstva pitne vode. Za povečanje varnosti pred kmetijskim onesnaženjem bi bilo treba v skladu s Strokovnim navodilom (UL SRS 10/1985) primerno urediti gnojišča v stajah z drobnico, tako da izcedne vode iz gnoja ne bi prosto odtekale v vodonosnik. Pri gozdarski dejavnosti je treba pri uporabi mehanizacije v gozdu paziti, da ne bi prišlo do izlitja olja in naftnih derivatov v tla. ZAHVALA Zahvaljujem se Primožu Kovačiču za strokovni prevod povzetka in Boštjanu Surini za tehtne pripombe ob pregledu prispevka. 102 ANNALES • Ser. hist. nat. -11 - 2001 • 1 (23) Gregor KOVAČIČ: POKRAJINSKA OGROŽENOST IN UKREPI ZA ZAŠČITO KRAŠKEGA IZVIRA BISTRICA, 93-104 THE ENVIRONMENTAL VULNERABILITY OF THE BISTRICA KARST SPRING AND SUGGESTED MEASURES FOR ITS PROTECTION Gregor KOVAČIČ Si-6250 litrska Bistrica, Maistrova IS E-mail: gregor.a.kovflcic@ktss-unMj.sl SUMMARY The Bistrica karst spring is, due to its landscape characteristics (fissure and karstified aquifer,), extremely vulnerable. Its bydrogeological background consists of the vast uninhabited forests of the deep karst Snežnik plateau. The spring is one of the most important drinking water resources in the south-western part, of Slovenia and has great potentials. The importance of the spring is intensified by the fact that there is no other adequate drinking-water resource in the wider area of the Ilirska Bistrica Comune that could be used as a substitute spring in the event of contamination. The procedures concerning the protection of the spring are stated in an inadequate act passed by the local community, and none of the water-protection measures have been carried out so far. The analyses of water samples taken from the spring have shown no signs of chemical contamination, although the microbiological quality of the spring is slightly lower than normal. The greatest threats to the spring are sports, construction, tourist and forestry activities taking place in the district, as well as traffic related to them. In order to ensure appropriate quality of the spring drinking water in the future, the following measures should be taken: rehabilitation of the lower quarry and the Črne njive shooting-ground, adequate sanitation for the SviSčaki tourist resort, regulation of the road system in the district of the spring, and a close control over the implementation of preventive measures concerning construction, forestry and farming in the areas in question. Key words: environmental vulnerability, the Bistrica karst spring, water-protection measures, water-protection areas LITERATURA Brenčič, M. & J. Prestor (1998): Vpliv gradnje avtocestnega križa v Sloveniji na vire pitne vode. Kakovost pitne vode in varstvo vodnih virov. Zbornica sanitarnih tehnikov in inženirjev Slovenije, Ljubljana. Zbornik predavanj, 91-100. Brumen, S., S. Lapajne, E. Vončina, L, Osvald, M. Babic & M. Medved (1991): Kataster kakovosti vodnih virov 1990. 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Ljubljana, DZS, 98-99. 104 MISCELLANEA ANNALES • Ser. hist nat. • 11 • 2001 • 1 (23) original scientific paper UDC 597.8(497.4) received: 11.4.2001 SEXUAL SIZE DIMORPHISM AND LIFE HISTORY TRAiTS OF TWO EUROPEAN SPADEFOOT TOADS (PEL OBA TES F USC US AND P. SYRIACUS) IN ALLOPATRY AND SYMPATRY Irena ROT-NIKČEVIČ institute for Biological Research "Siniša StankoviC", YU-11000 Beograd, 29. novembra 142 and Department of Anatomy and Neurobiology, CA-Halifax, Nova Scotia B3H 4H7, 5859 University Avenue, E-mail: nikcevic@is2.dal.ca Vesna SIDOROVSKA Macedonian Museum of Natural History, FYR Macedortia-91000 Skopje, Boulevard (linden 86 Georg DŽUK1Č institute for Biological Research "Sšniša Stankovih", YU-11000 Beograd, 29. novembra 142 Miloš L KAl.EZIČ institute of Zoology, Faculty of Biology, YU-11000 Beograd, Študentski trg 16 ABSTRACT We studied the variation in sexual size dimorphism (SSD) and life history traits in two spadefoot toad species (Pelobates fuscus and P. syriacus) across the part of southeastern European geographic distribution (Panonnian Plain and the Balkans), including the area of their sympatry. Species differ considerably in the body size of adult individuals, in the direction and the extent of SSD, while the differences in tadpole and juvenile sizes prior to or after metamorphosis, as well as in longevity and time of attainment of sexual maturity, appeared to be much smaller and without consistent variation pattern. Significant intraspecific variation was found in both species for body size, magnitude of SSD, average longevity and time of sexual maturity attainment. Intraspecific variation in these traits was much more pronounced in P. syriacus than in P. fuscus. Adult individuals of P. syriacus from the zone of strict sympatry were significantly smaller but larger as tadpoles and with the lower leve! of SSD. Also, these individuals had shorter life span and earlier sexual maturity (at least one year) than conspecific Individuals from the geographically remote allopatric part of the species range. Key words: spadefoot toads, body size, longevity, sexual maturity, intersex size difference DIMORFISMO SESSUALE DI TACLIA E TRATTI EVOLUTIVI Dl DUE SPECIE DI ROSPO EUROPEO (PELOBATES FUSCUS E P. SYRIACUS) IN ALLOPATRIA E SIMPATRIA SlNTESl Gli autori hanno studiato le variazioni nel dimorfismo sessuale di taglia (SSD) e nei tratti evolutivi di due specie di rospi pelobati (Pelobates fuscus e P. syriacus) dell'Europa sud-orientale (Pianura Pannonica e Balcani), considerando anche Varea della loro simpatria. Le specie si differenziano considerevolmente per le dimensioni degli individui adultiche ne caratterizzano, inoltre, iI dimorfismo sessuale di taglia. Le differenze riscontrate nelle dimensioni di girini ed individui in siadl giovanili, prima e dopo la metamorfosi, nella longevitá e ne! tempo di raggiungimento della maturita sessuale, appaiono minori e sprovviste di un modello di variazione consitente. Alcune significanti variazionl intraspecifiche sono state invece riscontrate in entrambe le specie per quanto riguarda le dimensioni corporee, l'ampiezza dell'SSD, la longevitá media ed il tempo di raggiungimento della maturita sessuale. Le variazioni intraspecifiche di questi tratti sono risultate piü marcate in P. syriacus che in P. fuscus. Gli individui adulti di P. syriacus provenienti dalle zone di simpatria stretta, esattamente come i girini, si sono rivelati significativamente piü piccoli ma piú tozzi, e con un livello minore di SSD. Questi individui hanno inoltre manifestato una durata della vita inferiore e una maturita sessuale anticipata (di almeno un anno) rispetto ai loro conspecifici provenienti dalla geográficamente distante parte allopatrica dell'estensione della specie. Parole chiave: rospi pelobati, dimensioni corporee, longevitá, maturita sessuale, differenze intersessuali di dimensioni 107 ANNALES • Ser. hist nat. • 11 • 2001 • 1 (23) leena ROT NIKČEVIČ et a/..-SEXUAL SIZE DIMORPHISM AND LIRE HISTORY TRAITS ..., 107-120 INTRODUCTION The spadefoot toad genus Pelobates includes three species in Europe (P. cultripes, P. fuscus and P. syriacus) and one in extreme northwestern Africa (P. varaldii). Common spadefoot toad, P. fuscus, has an extensive range, which covers most of the plains and hilly regions of central, eastern and southeastern Europe (Nollert, 1998). The eastern spadefoot toad, P. syriacus, has a contemporary distribution extending from the southern part of the Panonnian Plain and southeastward into Romania, Bulgaria, Greece, and southwestern Asia (Sofianidou, 1997). These species have a narrow zone of sympatry along the lower course of the Danube, as well as further south in the vicinity of the Bosphorus. The morphology and natural history of the three spadefoot species is quite similar. These amphibians are obligatory subterranean habitat specialists. Typical terrestrial habitats include sandy areas, heathlands and deciduous woodland on light density soils. They actively forage and are opportunistic feeders with a wide trophic niche (e.g. P. fuscus; Cogainiceanu et a!., 1998). During the day and dry periods they hide in deep burrows. When above ground, during migrations or when searching for food, they are strictly nocturnal. The spawning biotopes include a variety of mostly stagnant, meso- to eutrophic permanent water bodies. It might be that P. fuscus and P. syriacus differ in their ecological characters as they occur over different geographical ranges - P. fuscus has wider latitudinal and narrower altitudinal range than P. syriacus. In this regard, sympatic populations on the margins of their range may be non-representative for both species. Components of life history (principal sources of fitness) represent selective compromises to a suite of environmental variables accumulated over evolutionary time (Wilbur et ai., 1974). The assessment of life history traits among closely related species and/or conspecific populations within different habitats and regions should reveal potential sources of life history variation (e.g. Tilley & Bernardo, 1993). Also, differences in life history pattern observed in the field may sometimes be attributable to phenotypic or developmental plasticity expressed in response to variation in environmental variables (Stearns, 1992). However, the study of sympatric populations, especially syntopic ones, can potentially remove the obfuscating effects of environment differences. In other words, because two strictly sympatric species share habitat features to a large degree (including the same ponds for breeding in case of amphibians), interspecific differences in life history patterns are probably not due to phenotypic or developmental plasticity expressed in response to differences in environment, except for possible differences in sensitivity to population and predator densities. Foraging mode, phylogenetic inertia and morphological constraints (body size and shape) may also be factors potentially influencing variation of life history traits as in many ectotermtc groups (Dunham & Miles, 1985). For spadefoot toad species, the extent of sexual size differences and life history traits, assessed on a good sample size of a number of populations, are little known. Here we compare life history traits of two spadefoot toads, P. fuscus and P. syriacus across the Panonnian Plain and the Balkans, which include the area of sympatry with syntopically breeding sites. We were particularly interested in inter- and intraspecific variation in a number of life history characteristics, such as: tadpoles, juveniles and adult body sizes, age of adult individuals and time of attaining sexual maturity, as well as in direction and the extent of sexual size dimorphisms. Fig. 1: Distribution of the sampling sites of the spadefoot toads included in the analyses. Localities: 1 - Cavolj, 2 - Lesino kopovo, 3 - Utrine, 4 - Kresna, 5 - Saramzalino, 6 • Sekirnik, 7 - Prdejci. SI, 1: Geografska razporeditev vzorčevalnih mest čes- novk, vključenih v analizo. Lokalitete: 1 - Cavolj, 2 - Lesino kopovo, 3 - Utrine, 4 -Kresna, 5 - Saramzalino> 6 - Sekirnik, 7 - Prdejci. 108 ANNALES ■ Ser. hist, iiat • 11 • 2001 • 1 (23) Irena ROT NIK£EVi£ ef a/.rSEXUAl. SIZE DIMORPHISM AND UFE HISTORY TRAITS .,., KJM20 MATERIAL AND METHODS Study areas and population samples As an area where P. fuscus lives allopatrically with other spadefoot species, we chose the Subotica-Horgos Sand (Cavolj locality) and the river Tisa inundation area (Lesino kopovo locality, see figure 1). The Deliblato Sand (Utrine locality), situated in the extreme southeastern part of the Pa non nial depression, is the area where P. fuscus lives in sympatry with P. syriacus (D2uki£ & Pasuljevid, 1983). Lesino kopovo lies in an area with quite different geological and edaphic characteristics in comparison to the two Sands. The depression soil of the area is salt-affected and may be regarded as solonetz type according to edaphic classification (Nejgebauer ef aL, 1959). Allopatric P. syriacus populations, from which samples were taken, came from Bulgaria (one breeding unit) and the Former Yugoslav Republic of Macedonia, FYROM (three breeding units, Fig. 1). Locality position data (UTM code, longitude, latitude, altitude) as well as sample sites of tadpoles (at the stage 39; Cosner, 1960), juveniles (just after the metamorphosis) and of sexually matured individuals are presented in table 1. in order to obtain an adequate number of adult individuals of allopatric P. syriacus, we pooled individuals collected from these localities neglecting possible population effect on the studied characters' variabilities. The specimens used in this study are housed in the Georg D2tjki¿!s batrachological collection (institute for Biological Research, Belgrade) and in the collection of the Macedonian Museum of Natural History, Skopje, FYROM. Morphometries Individuals were weighed to the nearest 0.01 g. Nineteen morphornetric measurements were taken on each adult specimen's right side using digital caliper (to the nearest 0.01 mm): L - total body length (measured from the snout to cloaca), F - femur length (from the cloaca to the distal end of femur measured on bent Hindiimb), T - tibia length, P - pes length (measured from the metatarsal wrist to the apex of the longest, fourth, toe), Lpa - forelimb length (humerus length + length from the proximal articulation of humerus to the apex of the longest, 3rd finger), Lpp - hindlimb length (foot length to the apex of the longest toe, the 4th one), DpPa - length of forelimb first toe (from the proximal end of tubercle to the apex of the 1st finger), DsPa -forelimb second finger length (from the proximal end of tubercle to the apex of the finger), DpPp - length of hindlimb first toe (from the distal end of inner metatarsal tubercle to the apex of the toe), Cint - inner metatarsal tubercle length, Lc - head length (snout to mouth corner), Ltc - head width (between mouth corners), Spp -minimum interorbital space, Spi - minimum internarial space, Spcr - intercanthal distance, Lo - eye length, Ltp -upper eyelid width, Dro - snout to eye distance, Dno -nostrils to anterior eyelid commisure. Tadpoles and juveniles were measured for the total body length only (from the snout to the tail's tip for tadpoles and from the snout to cloaca for juveniles). 1 2 3 4 5 6 7 UTM code CS91 EQ26 EQ26 FM81 EM72 FL58 F126 Longitude 46°10' 44*50' 44°50! 41°43' 41°47' 41 °26' 41°1 2' Latitude 19°40' 21°18' 21 °18' 23°9' 21°57' 22°48' 22a31' Altitude (m) 100 80 95 180 280 210 65 P. fuscus Adults - females 8 27 26 . - . - Adults - males 39 16 5 - - - tadpoles 20 - 8 - - - - juveniles 17 - 14 - - - - P. syriacus Adults - females - „ 30 4 1 2 4 Adults - males - „ 21 14 2 1 2 tadpoles - - 10 - - - 10 juveniles - - 15 - - - 10 Tab. 1: Locality position data (UTM code, longitude, latitude, altitude) and sample sizes. Localities: 1 - Cavolj> 2 - Lesino kopovo, 3 - Utrine, 4 - Kresna, 5 - Saramzalino, 6 - Sekirnik, 7 - Prdejci Tab. 1: Lokalifeta (UTM, zemljepisna dolžina in širina, nadmorska višina) in velikost vzorcev. Lokalitete: 1 - Cavolj, 2 ~ Lesino kopovo, 3 - Utrine, 4 ~ Kresna, 5 - Saramzalino, 6 - Sekirnik, 7 - Prdejci 109 ANNALES • Ser. hist. nat. • 11 • 200t • 1 (23) !rena ROT NIkCEV'K! ,a al.: SEXUAL SIZE DIMORPHISM AND LIFE HISTORY TRAiTS ..., 107-120 Age and time of sexual maturation Individual ages were assessed by skefetochronology. A general description of this histological method can be found elsewhere (e.g. Castanet et a I., 1993). Frozen sections of the demineralized bones were cut at 16 pm and stained in Ehrlich's hematoxylin. Second phalange's diaphyseal portion of the forelimb's third digit was used for counting the lines of arrested growth (LAC), which corresponded to annual resting growth periods. A comparison of the number of LACs in the phalanges and in the femur of the same individuals (three toads of both species) revealed the same LAG numbers. We managed to assess an individual onset of sexual maturity as a sudden decrease in bone growth and concomitant rapprochement of LAGs (see Kleinenberg & Smirtna, 1969; Francillon-Vieillot et a!., 1990). Possible resorption of the first LAG, due to endosteal cavity growth, was taken into account when age was estimated, and one year added to the estimated age when resorption was obvious. Statistical analyses Various parametric and nonparametric tests were used to analyze data. One way ANOVA was used to analyze differences in body weight and morphometric traits between species and between sexes. Mahalanobis distances were calculated to measure overall morphometric differences between genders using the set of all 19 characteristics. A non-parametric Mann-Whitney U test described differences in age and time of attaining sexual maturity, while frequency distributions of age classes in females and males were tested by the Kol-mogorov-Smirnov test. We used the Tukey-Krarner test for multiple comparisons among means. Correlations between morphometric traits and between body measures and age were analyzed by the Spearman correlation test (Rs). All statistical analyses were performed using various STATISTICA program procedures. RESULTS Body size measures - intersexual and interlocality comparisons Descriptive statistics of adult body measures are presented for both species (Tabs. 2a-2e). Intersexual differences between P. fuscus toads from Cavolj and Utrine, but not from the Lesino kopovo locality, were significant in respect to almost all analyzed characteristics. Females were significantly larger than males, being apparently twice as massive. Among morphometric traits only toe lengths did not differ significantly between sexes. Males from Cavolj showed significantly larger values only for eye-length (ANOVA, p < 0.001) and interorbital distance (ANOVA, p < 0.05). In the Utrine population, even these measurements were not significantly larger in males. Mahalanobis distance between sexes in P. fuscus from Cavolj was estimated to be D2 ~ 20.23 (p < 0.001), and from the Lesino kopovo locality D2 = 12.92 (p < 0.01). This measure was not computed for the Utrine population due to the small sample size of males. Males and females from Lesinti kopovo locality were very similar in respect to age at maturity and age range and therefore presented a good sample for analyses, interestingly, intersexual differences were not significant, except that females were more massive and had longer femurs. Sexual dimorphism in the common spadefoot toad was seen, not only in overall body-size, but also in specific morphological characters such as limbs. Elongated fore- and hindlimbs in males can be regarded as characters that are favored in male-male competition for females and such sexual dimorphism has been found for some anuran species (Halliday & Tejedo, 1995), but the fight between Pelobates males (paired-unpaired) has not been documented yet (Eggert, pers. comm.). Much larger fore- and hindlimbs in males than in females, relative to body length, were confirmed for the common spadefoot toad from Cavolj (Lpa/L, p < 0.05; Lpp/L, p < 0.01). Also, Cint/L index (inner metatarsal tubercle length/body length) appeared to be significantly larger in males compared to females (ANOVA, p < 0.001). However, such sexual dimorphism was not found in the other two population samples, Utrine and Lesino kopovo. interpopulation comparisons between P. fuscus samples revealed that individuals from Utrine and Cavolj did not differ statistically in respect to most morphometric traits, but in a few cases differences were apparent. Notably, hind limbs and head dimensions were significantly larger in males from Cavolj (ANOVA, p < 0.05), while females from the same population were smaller than their counterparts from Utrine in respect to all traits that showed significant differences; i.e. hind limbs, inner metatarsal tubercle, eye-length and interorbital distance. However, when samples from Cavolj and Lesino kopovo were compared, significant differences appeared in almost all characters (ANOVA, p < 0.001), individuals of both genders from Cavolj being larger. Differences were not significant only for total body length and intercanthal distance in males and for intercanthal distance and minimum interorbital space in females, Utrine vs. Lesino kopovo comparison revealed significant differences only in females (in all characters except for minimum interorbital space and eye length), with Lesino kopovo individuals being smallest in comparison to the other two populations. P. syriacus from Utrine did not show any intersexual differences in morphometric characters. Mahalanobis 110 ANNALES • Ser. hist. nat. It • 2001 • 1 (23) Ire ma ROT NIKCEVlC eta!.: SEXUAL SEE DIMORPHISM AND UEE HISTORY TRAITS ..., ¡07-120 distance between sexes in P. syriacus from this population was estimated to be D2 = 9.758 (p > 0.05). Neither females nor males of this species differed significantly in hindlimb lengths and the size of metatarsal tubercle relative to body size (ANOVA, p > 0.05). However, forelimbs were much larger in males in comparison to females (ANOVA, p < 0.001). Contrary, intersexual differences in allopatric P. syriacus individuals from FY-ROM+Bulgaria were statistically significant in respect to all analyzed traits. Males appeared to be larger than females. The most prominent differences were in weight, body length, fore- and hindlimbs and toe length (ANOVA, p < 0.001). Mahalanobis distance between the sexes of P. syriacus from this sample was significant (D2 = 41.22, p < 0.05). Elongated fore- and hindlimbs in males vs. females appeared to be statistically significant (ANOVA: Lpa/L, p < 0.05; Lpp/L, p < 0.01), but the size of metatarsal tubercle relative to body size failed to show dimorphism (ANOVA, p > 0.05). Males being larger than females is a very interesting result for it is not common in amphibians. Yet, both male and female samples lack young adults (Fig. 3) and the individuals that we compared might have been close to the maximum size they would reach. Interpopulation comparison within the eastern spadefoot revealed that allopatric females and males (FYROM -r Bulgaria) were significantly larger than individuals living in sympatry with the common spadefoot (Utrine) for most morphometric traits in females (except in nostrils to anterior eyelid commisure distance) and all traits in males with the most prominent differences being in total body length and weight (ANOVA, p < 0.001). Again, in allopatric population both male and female samples Sack young adults and the differences in body sizes could be due to differences in age classes in samples compared, and not to presumable atlopa-try/sympatry differences. Pelobates syriacus (Utrine) Males (N~21) Females (N=30) Variable X + SD range X ± SD range SSD signif. Weight 28.91 ± 13.49 10.26-60.76 32.01 ±15.68 11.63-71.92 1.15 n.s. L 61.13 ± 8.97 47.55-75.62 60.8.3 ±8.93 47.84-79.56 1.00 n.s. F 28.90 ±4.92 20.47-37.81 29.27 ±4.75 22.47-40.47 1.01 n.s. T 23.86 ±3.60 18.54-32.45 23.77 ±3.13 17.84-32.54 1.00 n.s. P 30.63 ± 5.04 22.64-38.44 28.15 ± 4.65 18.51-37.39 0.92 n.s. Lpa 41.65 ± 8.47 30.90-58.18 38.85 ± 6.41 28.20-53.04 0.93 n.s. Lpp 93.52 ± 14.95 67.81-121.91 92.96 ± 13.21 73.63-128.22 0.99 n.s. Dp Pa 10.24 ± 1.57 7,66-12,81 9.99 ±1.59 7.22-14.33 0.98 n.s. DsPa 8.92 ±1.76 6.12-12.43 8.61 ±1.66 6.40-13.09 0.97 n.s. DpPp 5.69 ± 1.25 3.65-8.12 5.41 ±0.95 3.56-7.80 0.95 n.s. Ci nt 5.78 ±0.97 4.40-7.53 5.73 ±1.12 4,12-8.24 0.99 n.s. Lc 16.47 + 2.92 12.30-20.37 16.44 ±2.62 1 1.24-23.62 1.00 n.s. Ltc 20.01 ± 3.83 14.46-26.55 19.42 ±2.73 14.53-30.76 0.97 n.s. Spp 7.26 ±1.10 4.76-9.81 7.30 ±1.03 4.78-9.67 1.01 n.s. Spi 4.38 ± 0.70 3-49-5.89 4.67 ± 0.68 3.46-6.44 1.07 ri.s. Spcr 8,72 ± 1.02 6.64-11.08 8,93 ± 1.21 6.34-11.26 1.02 n.s. lo 6.62 ±0.91 5.01-8,40 6.81 ±0.87 4.98-8.88 1.03 n.s. Ltp 5.30 ±0.54 4.60-6.37 5.04 ± 0.79 2.77-6.79 0.95 n.s. Dro 9.42 ± 1,28 7.42-11.33 9.62 ± 1.37 6.65-12.79 1.02 n.s. Dno 5.84 ±1,01 4.30-7.64 5.94 ±0.73 4.48-9.30 1.02 n.s. Tab. 2a: Differences in morphometric characters between sexes in Pelobates syriacus from Utrine locality. X - mean value, SO - standard deviation, SSD - female/male size ratio values. Symbols (* P<0.05; ** P<0.01; *** P<0.001; n.s. - non significant) denote the significance level of SSD, obtained by ANOVA test. Tab. 2a: Morfometrične razlike med spoloma Peiobates syriacus z lokalitete v Utrinah. X ~ srednja vrednost, SD - standardni odklon, SSD (VRS) je velikostno razmerje med spoloma. Simboli (* P<0,05; ** P<0,01; ***' P<0,001; n.s. ~ ni signifikantno) ponazarjajo interval zaupanja SSD> dobljen s testom ANOVA. 111 ANNALES • Ser. hist. nat. • 11 ■ 2001 • 1 (23) If ena ROT NIKČEVld eta/.; SEXUAL SIZE DIMORPHISM AND LIFE HISTORY TRAITS 507-120 Tab. 2b: Differences in morpbometric characters between sexes in Pelobates syriacus from FY ROM & Bulgaria localities (for legend see table 2a), Tab. 2b: Morfometrične razlike med spoloma Pelobates syriacus z lokalitet v Makedoniji in Bolgariji (legenda: glej tabelo 2a). Pelobates syriacus (FYROM & Bulgaria) Males (N=19) Females (N=11) Variable X ± SD range X ± SD range SSD signif. Weight 53.89 ± 6.44 43.28-66.81 44.80 ± 639 35.15-56.35 0.81 *** L 75.81 ± 3.06 68.75-79.73 70.51 ±4.08 66,14-79.34 0.93 *** F 36.53 ± 1.87 31.48-39.73 33.24 ±2.31 29.74-36.93 0.91 T 29.90 ± 1.35 27.31-33.46 27.71 ±1.91 24,24-30.25 0.93 ** P 42.01 ± 2.36 37.07-46.09 36.47 ±2.77 31.48-40.47 0.87 *** Lpa 55.60 ± 2.43 50.46-59.77 48.91 ±5.39 42.49-62.77 0.88 Lpp 120.45 ±5.55 106.09-130.43 107.64 ±6.81 97.27-117.83 0.89 * * H1 DpPa 15.09 ± 1.01 13.21-16.53 12.53 ±1.60 8.34-14.55 0.83 *** DsPa 15.63 ±0.82 13.51-16.53 13.68 ±0.87 12.12-14.88 0.88 *** DpPp 16.10 ± 1.14 13.54-17.60 15.40 ± 1.11 13.75-17.17 0.96 n.s. C i nt 7.08 ± 0.44 6.17-7.72 6.74 ± 0.55 5,67-7.71 0.95 n.s. Lc 25.06 ±0.99 23.34-27.61 23.25 ± 1.31 21.86-25.91 0.93 * Ltc 29.72 ±1.77 25.10-32.03 28.09 ±1.62 25.90-30.73 0.95 * Spp 8.18 ±0.77 6.36-9.74 8.10± 1.06 6.36-10.37 0.99 n.s. Spi 6.47 ±0.45 5.48-7.19 5.99+0.47 5,31-6.76 0.93 ** Spcr 10.90 ±0.72 9.58-12.54 10.77 ± 1.06 8.86-12.45 0.99 n.s. Lo 9.05 ±0.51 8.03-9.90 8.44 ±0.57 7.78-9.59 0.93 Ltp 6.23 ±0.28 5.62-6.70 6.02 ±0.26 5.67-6.50 0.97 n.s. Dro 11.82 ±0.60 10.55-12.74 11.10 ±0.50 10.41-11.78 0.94 ** Dno 6.73 ±0.52 5.57-7.64 6.34 ±0.37 5,7 0-6.73 0.94 Tab. 2c: Differences in morpbometric characters between sexes in Pelobates fuscus from Utrine locality (for legend see table 2a). Tab. 2c: Morfometrične razlike med spoloma Pelobates fuscus z lokalitete v Utrinah (legenda: glej tabelo 2a). Pelobates fuscus (Utrine) & Males (N=5) Females (N=26) Variable X i SO range X ± SD range SSD signtf. Weight 10.37 ±1.18 8.73-12.06 17.18 + 6.45 10.22-32.95 1.66 + L 44.79 ±2.77 41.21-48.08 53.71 ±5.22 46.45-65.16 1.20 *** F 20.46 ± 1.35 18.99-22.30 23.44 ± 2.56 19.34-27.95 1.15 T 16.65 ±0.98 15.24-17.79 20.00 ± 1.90 16.50-24.64 1.20 P 20.24 ±1.44 18.45-22.21 24.65 ± 3.02 19.46-31.92 1.22 Lpa 30.39 ± 2.42 27.61-33.89 35.01 ±3.39 28.54-40.96 1.15 * LPP 66.05 ±3.48 62.01-71.46 75.53 ± 7.47 66.47-92.02 1.14 n.s. DpPa 7.70 ± 1.01 6.43-9.12 8.75 + 1.16 6.55-11.99 1.14 n.s. DsPa 6.70 ± 1.17 5.66-8.17 7.94 ±1.27 5.11-10.63 1.19 n.s. DpPp 4.10 ±0.34 3.80-4.56 4.24 ±0.59 3.33-5.58 1.03 n.s. Cint 4.02 ± 0.31 3.69-4.50 4.75 ±0.57 3.67-6.04 1.18 * Lc 11.95 ±0.92 12.75-0.92 14.66 + 1.37 11.22-18.65 1.23 Ltc 14.40 ± 1.79 12.10-17.11 18.66 ±2.37 14.65-24.26 1.30 *** Spp 5.48 ± 0.48 4.77-6.02 5.84 ± 0.75 4.42-7.60 1.07 n.s. Spi 3.92 ± 0.37 3.28-4.24 4.57 ±0.69 3.52-6.31 1.17 n.s. Spcr 6.1 6 ±0.86 5.20-7.42 7.26 ±0.75 6.14-9.20 1.18 ** Lo 5.30 ±0.55 4.80-6.07 5.04 ±0.81 3.99-6.75 0.95 n.s. Ltp 3.86 ±0.43 3.27-4.20 4.51 ±0.44 3.64-5.36 1.17 ** Dro 6.85 ± 0.59 6.02-7.63 8.03 ± 0.94 6.22-10.11 1.17 * Dno 3.88 + 0.44 3.24-4.30 4.68 ± 0.65 3.02-5.62 1.21 * 112 ANNALES ■ Ser. hist. nat. • 11 • 2001 ■ 1 (23) Irena ROT NIKČEV1Č e! ai.: SEXUAL SIZE DIMORPHISM AND LITE HISTORY TRAITS ..., 107-120 Tab. 2d: Differences in morphometric characters between sexes in Pelobates fuscus from Cavoij locality (for legend see table 2a). Tab. 2d: Morfomelrične razlike med spoloma Pelobates fuscus z lokalitete vCavolju (legenda: glej tabelo 2a). Pelobates fuscus (Cavoij) Males (N=39) Females (N~28) Variable X±SD range X±SD range SSD signif. Weight 12.54 + 2.69 7.79-18.57 19.14 ± 5.82 8.87-32.49 1.53 L 46.00 ±3.12 40.57-56.65 54.02 ± 4.46 47.07-62.15 1.17 *** F 22.76 + 2.09 16.44-25.67 23.99 ±2.15 20.15-30.57 1.05 * T 18.61 ±1.25 16.19-20.79 19.95 ± 1.70 16.10-23.29 1.07 *** P 23.66 ± 1.67 20.03-26.18 28.73 ±4.19 21.89-36.19 1.21 *** Lpa 31.98 ±3.88 13.60-37.85 34.51 ± 3.45 28.22-41.48 1.08 ** Lpp 74.12 ±4.67 63.16-83.66 73.40 ± 9.21 59.07-90.18 0.99 n.s. DpPa 8.13 + 0.86 6.01-9.56 7.89 ± 0.88 6.52-9.77 0.97 n.s. DsPa 6.76 ± 0.62 5.50-8.07 7.24 ± 0.98 5.83-9.27 1.07 * DpPp 4.40 ± 0.55 3.26-5.72 4.62 ±0.70 3.51-6.13 1.05 n.s. Ci nt 4.24 ± 0.35 3.19-5.12 4.36 ±0.50 3.30-5.68 1.03 n.s. Lc 12.88 ± 1.05 11.04-15.96 14.07 ±1.20 11.80-17.20 1.09 *** Ltc 15.72 ± 1.86 12.61-20.30 18.86 ±1.78 14.66-22.01 1.20 *** Spp 5.81 ± 0.54 4.90-6.79 5.53 ±0.55 4.50-6.67 0.95 Spi 4.43 ± 0.48 3.17-5.95 4.63 ±0.71 3.29-6.27 1.05 n.s. Spcr 7.07 ± 0.57 5.99-8.15 7.64 ± 0.60 6.63-8.79 1.08 *** Lo 5.42 ± 0.77 3.81-6.67 4.34 ± 1.04 3.25-7.47 0.80 *** Ltp 3.81 ±0.52 2.63-5.13 4.28 ±0.56 3.27-5.96 1.12 Dro 7.37 ±0.76 6.24-9.33 8.19 ±0.77 6.96-9.99 1.11 *** Dno 4.31 ±0.55 3.51-6.27 4.7 ±0.50 3.68-6.18 1.09 Comparisons between species from the zone of sym-patry {Utrine) revealed statistically significant differences in almost all analyzed traits. Both males and females of P. syriacus were significantly larger than their P. fuscus counterparts (ANOVA, at least at p < 0.05). On average, the largest tadpoles and juveniles were those of P. fuscus from the zone of sympatry (LJtrine) and the smallest ones were preadult individuals of the same species from the zone of allopatry (Cavoij, Tab. 3). We only compared tadpoles and juveniles from the same locality, since it is known that tadpole size in anurans is strongly related to tadpole density and the amount of food available in the pond. Interspecific differences (Utrine locality) were not statistically significant neither in tadpoles nor in juveniles (ANOVA, p>0.05). P. fuscus juveniles reached on average only 35.7% (Cavoij) and 33.8% (Utrine) of the tadpole size prior to metamorphosis, while in P. syriacus populations figures were 34.9% (FYROM) and 35.2% (Utrine). It was also interesting to compare juvenile with the adult body size. On average, P. fuscus juveniles were from 58.1% (Cavoij) to 61.0% (Utrine) of adult females, and from 68.5% (Cavoij) to 73.2% (Utrine) of adult male body size. In P. syriacus, on average, juveniles reached 53.1% of adult female body size in Utrine population and 43.9% of female body size in the FYROM+Bulgaria population. Age and time at sexual maturation The life span of adult spadefoot toad species studied ranged from 3 to 16 yr. in P. fuscus, and from 2 to 16 yr. in P. syriacus species (Tab. 4). Such an old individuals in both species has not been recorded so far. Biegler (1966) noticed an 11 years old P. fuscus in captivity, while Eggert & Guyetant (1999) and Wiener (1997) reported 9 years old individuals in the field. On average, the oldest were males of the common spadefoot from Cavoij locality (10.21 ± 2.73 yr.), while the youngest were females of the eastern spadefoot from Utrine (4.59 ± 1.56 yr.). Distributions of age classes are given in figures 2 and 3. Differences between genders within locality, as well as differences between localities within sex appeared to be insignificant except in few cases. Males from Cavoij were significantly older then males from Lesino kopovo (Mann-Whitney U test, p < 0.05), and males from Utrine locality (p < 0.01). Also, intersexual difference in age was significant in the Utrine population sample (females were older than males, Mann-Whitney U test, p < 0.05). However, as we managed to score age for only four Utrine males, these differences should be taken with caution. !f we exclude an exceptionally old male of 16 yr. from the Utrine sample of P. syriacus, even nine years older than the oldest other males, difference between genders in this population appeared insignificant. 113 ANNALES • Ser. hist. nat. 11 ■ 2001 ■ 1 (23) Irena ROT NIKČEVIČ ef a!.: SEXUAL SIZE DIMORPHISM AND LIE E HISTORY TRAITS..., ¡07-1 JO Tab. 2e: Differences in morphometric characters between sexes in Pelobates fuscus from Lesino kopovo locality (for legend see table 2a). Tab. 2e: Morfometrične razlike med spoloma Pelobates fuscus z lokalitete Lesino kopovo (legenda: glej tabelo 2a). Pelobates fuscus (Lesino kopovo) Males {N=16) Females 0.05). The common spadefoot toads reached sexual maturity at the age of two to five years, while those of eastern spadefoot species at the age of two to four years (Tab. 5). Intersexua! differences in this life history trait were negligible in both species (Mann-Whitney U test, p < 0.05). Still, male sample from Cavolj lacks young adults (younger than 6 years) which may not allow to obtain accurate results when compared with female sample from the same locality (our analysis shows that both sexes matured at the same age). Also, our male sample from Utrine was not large enough, so these results should not be taken as definite ones. However, withsn-species variation existed. Thus, both genders of the Cavolj population matured earlier than individuals from Lesino kopovo (Mann-Whitney U test, p < 0.05), while males from Utrine locality matured much earlier than males from Lesino kopovo (Mann-Whitney U test, p < 0.05). The eastern spadefoot toads of both genders from FYR Macedonia and Bulgaria attained sexual maturity significantly later than individuals from Utrine population (Mann-Whitney U test, p < 0.001). Comparison between spadefoot toads from the zone of sympatry (Utrine) revealed that P. fuscus females had a significantly longer life span and they matured later than P. syriacus of the same gender (see Tabs. 4 and 5; Mann-Whitney U test, p < 0.001 and p < 0.05, respectively). On the contrary, P. syriacus males were older and they attained sexual maturity later than P. fuscus ones (Mann-Whitney U test, p < 0.001 and p < 0.05, respectively). Relation between age and size None of the morphometric characters in the analyzed samples showed significant correlation with age (Rs test, p > 0.05). From our data, we concluded that body length is a poor predictor of age as there is considerable size variability observed within most age-classes. For example, 10 years old males of the common spadefoot toad from Cavolj can be as large as 40 to 56 mm, or females of that age from Lesino kopovo range in size from 42 to 65 mm (Fig. 2). Among the eastern 114 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Irena ROT NIKCEVKd e< a/.: SEXUAL SIZE DIMORPHISM AND LIFE HISTORY TRAITS ..., 107-120 spadefoot toads females in the fourth year of age varied in size from 50 to 77 mm (Fig. 3). One should bear in mind that anuran growth generally follows Von Berta-lanffy curve, that is, growth is faster at earlier stages than after reaching sexual maturity. After sexual maturation annual growth rate will strongly decrease and become quite low. But, young adults are smaller than old adults because growth does not stop at sexual maturity, but only decreases rapidly. Tab. 3: Ranges, mean (X) and standard deviations (SD) for body length (mm) in analyzed tadpole and juvenile spadefoot toad samples. Tab. 3: Razpon, srednje vrednost/ (X) in standardni odkloni (SD) v dolžini telesa (mm) pri analiziranih paglavcih in mladostnih osebkih česnovk. Tadpoles Juveniles sample N X±SD range N X±SD range Pelobates fuscus Utrine 8 96.89+9,06 80.93-113.16 14 32,74+3.08 27.38-36.64 Ca vol j 20 84.61 ±6.99 70.42-96.19 17 30.2611.46 27.97-34.01 Pelobates syriacus Utrine 10 91.50+8.54 79.93-104.71 15 j 32.16+3.41 26.30-37.90 FYROM 10 88.74±1 5.25 60.63-108.18 10 j 30.94±1.78 28.18-33.44 70 65 60 55 ? H J 50 45 40 35 0 2 4 6 8 10 12 14 16 18 Age (years) o U trine-males • Utrine-females a Cavolj-males a Cavolj-females a Lesino kopovo-males a Les. kopovo-females Fig. 2: Distribution of body size (L) and age in the adult Pelobates fuscus individuals. SI. 2: Velikostna (L) in starostna razporeditev pri odraslih osebkih Pelobates fuscus. 115 ANNALES • Ser. hist, nat. • 11 • 2001 • 1 (23) Srena ROT NIKČEVIČ eí ai.: SEXUAL SIZE DIMORPHISM AND L¡¡:£ HISTORY TRAITS , 107-120 S J e 8 10 Age (years) 12 14 16 18 o U time-males ® U trine-females a FYROM+Bul.-males a F YROM+BuI. -females Pig. 3: Distribution of body size (L) and age in the adult Pelobates syriacus individuals. Si 3: Velikostna (L) in starostna razporeditev pri odraslih osebkih Pelohat.es syriacus. Tab. 4: Descriptive statistics for the age in Pelobates fuscus and Pelobates syriacus samples (for legend see table 2a). Tab. 4: Opisna statistika za starost osebkov Pelobates fuscus in Pelobates syriacus (legenda: glej tabelo 2a). Females Maies sample N X±SD range N X ± SD range sign. Pelobates fuscus Utrine 15 7.93 ±2.55 4-14 4 5.00 ± 2.00 2-6 * Cavoij 22 8.32 ± 2.10 3-13 37 10.21 ±2.73 6-16 n.s. Lesino kopovo 11 8.00 ± 2.64 4-13 9 7.89 ±2.80 4-14 n.s. Pelobates syriacus Utrine 22 4.59 + 1.56 2-8 14 6.00 ± 3.26 3-16 n.s. FYROM & Bul. Macedonia 8 9.63 + 2.39 7-15 16 9.38 ± 1.78 6-12 n.s. 116 ANNALES • Ser. hist. nat. 11 - 2001 • 1 (23) Irena ROT NfKČEViC eSsl.: SEXUAL SIZE DIMORPHISM AND Llli HISTORY TRAITS 107-120 Tab. 5: Descriptive statistics for the time of attaining sexual maturity in Pelobates fuscus and Pelobates syriacus samples (for legend see table 2a). Tab. 5: Opisna statistika za starost, ko osebki Pelobates fuscus in Pelobates syriacus dosežejo spolno zrelost, (legenda: glej tabelo 2a). Females | Males sample N X±SD range j N X ± SD range sign. Pelobates fuscus Utrine 11 3.27 ±0.79 2-4 2 2.00 ± 0.00 2-2 n.s. Cavolj 12 2.75 ±0.62 2-4 18 2.78 ±0.55 2-4 n.s. Lesino kopovo 10 3.60 ±0.84 2-5 6 3.50 ± 0.84 3-5 n.s. Pelobates syriacus Utrine 10 j 2.30 ± 0.49 ! 2-3 9 2.67 ±0.50 2-3 j n.s. FYROM & Bulgaria 4 } 3.50 ±0.58 j 3-4 10 3.10 + 0.52 3-4 I n.s. Apparently, spadefoot toads are among many tailless amphibians where body size is strongly influenced by juvenile growth rate followed by a reduction in somatic growth after sexual maturation (Halliday & Verreli, 1988; Platz & Lothrop, 1993; Hota, 1994). A sudden decrease in bone growth and concomitant rapprochement of LAG s in P. fuscus and P. syriacus was obvious in approximately 56% of the individuals studied, in other individuals the absence of such a pattern was probably due to a prolonged period of growth after the onset of sexual maturity. However, if we take into account only individuals which did not show such a LAG pattern {i.e. that did not show sudden decrease in bone growth and grew rather evenly), a statistically significant positive correlation between size and age was found for the P. syriacus (Rs = 0.672, p < 0.001}, but not for the P. fuscus where correlation was negative, though insignificant (Rs 0.191, p > 0.05). There were significant differences in size among age-classes when tested on pooled data for species. Age-classes were organized in the following way: i (2-7 yr.}, II (8-11 yr.) and III (12-16 yr.). In P. fuscus intersexual differences in body size in all age-classes were statistically significant (Mann-Whitney U test; I: p < 0.001, II: p < 0.001 ; ill: p < 0.01), females being larger than males. In P. syriacus most individuals belonged to age-class II, and intersexual differences in body size were significant (p < 0.001), but males had larger body length than females. A posterior analysis among age-classes did not reveal significant differences in size between age-classes (Tukey-Kramer test, p > 0.05). Distribution of total body length in respect to age clearly showed, especially when analyzing P. fuscus population from Cavolj, that females had greater body length than males from the same age class (Fig. 2). in P. syriacus such relation was not present (Fig- 3). DISCUSSION Sexual size dimorphism Among anuran species females appear to be larger than males in 90 % of cases (Shine, 1979). This pattern was found to be true in P. fuscus, P. cultipres and P. varaldii (Halliday & Tejedo, 1995) in many parts of their range. The magnitude of sexual dimorphism (average body size of females vs. males) in the common spade-foot toad known so far range from 1.03 (Lesino kopovo, this study) to 1.13 (Poland, Andrzejewski et a\., 1977). However, the eastern spadefoot toad males and females show more similar body lengths (1.01, Serbia, this study) or males are significantly larger than females (0.88 in Turkey, Zaloglu, 1964; 0.93 in FYR Macedonia and Bulgaria, this study). In the case of FYR Macedonia and Bulgaria sample we fail to have young adults in both 56X6S and the intersexual comparison was done on individuals that probably, in both genders, were close to the maximum size they would reach. Therefore, an interesting result appeared - males were larger than females which is not common in amphibians. In general, sexual size dimorphism in any species may be a consequence of differences in some life history traits and the action of sexual and/or natural selection, including fecundity selection. Thus, the direction and the degree of SSD may be the result of different selective regimes usually acting separately on females and males. The importance of these regimes varies among species and populations, or even with time in the same population (e.g. Howard, 1981; Halliday & Verreli, 1986). Several hypotheses, not mutually exclusive, have been proposed for the evolution of sexual size dimorphism. The most fundamental ones are (1) sexual selection (competition between males and female choice which mostly favors large males), (2) fecundity selection which favors large females, and (3) intersexual niche divergence (for 117 ANNALES • Ser. hist. nat. • 11 • 2001 • 1 (23) Irena ROT NIKCEVlC « ai.: SEXUAL SIZE DIMORPHISM AND LIFE HfSTORY TRAITS .... 107-120 amphibians see reviews in Hailiday & Verrell, 1986; Shine, 1989; Hailiday & Tejedo, 1995). The evolution of SSD is likely to evolve by interrelationships and correlated trade-offs between life-history adaptations, sexual selection and parameters of fecundity. in genera), as far as proximate determinants of sexual size difference in poikilothermic vertebrates are concerned, of especial importance are difference in age at maturity, longevity, differential growth and mortality rates, in relation to either body-size and age during preadult (larval and juvenile) and adult phases of ontogeny. Among life history characteristics, the timing of maturation is a critical event influencing both morphology and fitness (i.e. lifetime reproductive success) of the individuals, as well as the demographic structure of populations and species (Stearns, 1992; Ryan & Sem-litsch, 1998). A delay in first reproduction, as large as two years, by females in comparison to males is common in amphibian populations (Hailiday & Tejedo, 1995). By delaying maturation, females attain larger body-size at first breeding with a resulting benefit in reproductive performance. The timing of maturation seems to be rather conservative in the genus Pelobates, regardless of the region studied, ranging from 2 to 5 years in both genders (Hailiday & Tejedo, 1995; this study). Interestingly, in one population of the western spadefoot toad females breed at earlier age than males, which is correlated with a lower level of SSD in comparison with conspecific populations, where females breed later than males, showing higher level of SSD in favor of females (Talavera, 1989). However, in both spadefoot toad species we studied, the time of sexual maturity did not vary significantly between sexes and concomitantly did not affect SSD extent. In comparison to other life history traits with potential effect on the magnitude of SSD studied here, individual age appears not to be sex-specific in any of the spadefoot toad species studied. intra- and interspecific differences in life history traits Size is a dominant ecological factor, particularly among groups with indeterminate growth. Together with age, size is important in determining mortality and fecundity, and in influencing competition within and between species. The importance of body size in the ecology, life history, and reproductive success has been widely acknowledged for years (e.g. Fairbairn, 1997). ThLis, the pattern of interspecific variation in body size is expected to reflect pattern of adaptive divergence within the species range. That is why one may expect differences in size between individuals of species living in sympatry with other cognate species in comparison to conspecific individuals living in allopatry to decrease and/or escape between-species competition. Contrary to the expectations, spadefoot toads of species living in sympatry appeared not to be consistently larger than conspecific individuals from allopatric parts of the species range. Moreover, sympatric eastern spadefoot toads are significantly smaller than individuals from allopatric populations. However, this finding appears not to be related to sympatry/a 11 opat ry at all as deficit of young adult males and females was observed in the allopatric population. Also, males and females reached maturity later and were older in allopatric than in sympatric population, which resulted in larger individuals in the ailopairic situation. As for the interpopulation differences in some life history traits assessed by means of skeletochronology, significant variation was found in both species in the average individual longevity and time of attaining sexual maturity. Of special interest is the fact that P. syriacus from the zone of sympatry with P. fuscos have shorter life span and breed at least one year earlier in comparison to individuals from allopatric parts of the species range. Thus, our study provides evidence that local environment influences some intraspecific variation in life history traits. However, syntopic spadefoot toad individuals, which share habitat features to a large degree, show number of differences in life-history traits. First, P. syriacus adult individuals are significantly larger than P. fuscus ones. Most likely this is due to substantial difference in the growth rate of juveniles. Namely, our preliminary results (unpublished) revealed that the juvenile growth rate during the first month was almost twice in P. syriacus than in P. fuscus living syntopically (Utrine locality). In addition, these two species differ in the magnitude of SSD. They have a different life span and reach sexual maturity at a different age, especially in the females, it might be that our analysis substantiates the possibility that lineage-specific effects can explain some of the pattern of covariation in life history data within the European spadefoot toads. ACKNOWLEDGEMENTS We thank Miroslav Markovid for collaborating in fieldwork and sharing his data on spadefoot toads distribution and chronology in the Deliblato Sand. Petar Kubatovií and jovan Bradvorevitf (Serbia Forest) kindly provided facilities and logistic support through the study. Our colleagues Dr. Vladimir Beskov and Dr. Svetozar Petkovski assisted with fieldwork in Bulgaria and FYROM, respectively. We also thank Katarina Ljubi-savljeviC and Ljiljana Tomovítí for their technical assistance. 118 ANNAIES Ser. hist. nat. • 11 - 2001 • 1 (23) Irena ROT NIKČEVIČirf si.: SEXUAL SIZE DIMORPHISM AND LIFE H ¡STORY TRAITS ..., 1O7-120 VELIKOSTNE RAZLIKE MED SPOLOMA IN ŽIVLJENJSKE ZNAČILNOST! DVEH EVROPSKIH ČESNOVK (PELOBATES FUSCUS IN P. SYRIACUS) V ALOPATRI)! IN SIMPATRIji Irena ROT-NIKČEVIČ institute for Biological Research "Siniša Stankovih", YU-1'iOOO Beograd, 29. novembra 142 and Department of Anatomy and Neurobiology, CA-Haiifax, Nova Scotia B3H 4H7, 5859 University Avenue E-mail: nikcevic@is2.dat.ca Vesna SIDOROVSKA Macedonian Museum of Natural History, FYR Maceclonia-91000 Skopje, Boulevard i linden 86 Georg DŽUKIČ institute for Biological Research "SirsiSa Stankovih", YU-1 i 000 Beograd, 29. novembra 142 Miloš L. KALEZIČ Institute of Zoology, Faculty of Biology, YU-1100Q Beograd, Študentski trg 16 POVZETEK Avtorji pričujočega znanstvenega dela so preučevali velikostne razlike med spoloma (VRS} in življenjske značilnosti dveh česnovk (Pelobates fuscus in P. syriacus) v delu njunega areala v jugovzhodni Evropi (Panonski nižini in na Balkanu), vključno z območjem njune simpatričnosti. Vrsti se močno razlikujeta po velikosti odraslih osebkov in glede na stopnjo VRS, medtem ko so bile velikostne razlike pri paglavcih in mladostnih osebkih kot tudi v življenjski dobi in času, potrebnem za spolno zrelost, videti precej manjše in brez kakšnega doslednega variacij-skega vzorca. Pomembne razlike znotraj vrst so bile odkrite tako pri P. syriacus kot P. fuscus, in sicer v telesni velikosti, stopnji VRS, povprečni življenjski dobi in času, potrebnem za spolno zrelost. Razlike znotraj vrst v teh značilnostih so bile veliko bolj poudarjene pri vrsti P. syriacus kot pri P. fuscus. Odrasli osebki vrste P. syriacus iz območja striktne stmpatrije so bili neprimerno manjši, vendar večji kot paglavci in z manjšo stopnjo VRS. Osebki so imeli tudi krajšo življenjsko dobo in so postajali spolno zreli hitreje (najmanj leto dni) kot istovrstni osebki iz geografsko oddaljenih alopatričnih delov specifičnega areala. Ključne besede: rod česnovk, Pelobates fuscus in P. syriacus, velikost, življenjska doba, spolna zrelost, velikostne razlike med spoloma REFERENCES Andrzejewski, H., A. Prystslski & B, Wilczynska (1997): The biometric structure of population of the common spade-foot (Pelobates fuscus Laur., Salientia, Amphibia) of the environs of Aleksandrow Kujawski. Acta Biologies Cracoviensia, Ser. Zoologia, 20, 65-73. Biegler, R. (1966): A survey of recent longevity records for reptiles and amphibians in zoos. IZY, 6, 487-493. Cogalniceanu, D., F. Aioanei, C. Cittbuc & A. Vadineanu (1998): Food and feeding habits in a population of common spadefoot toads (Pelobates fuscus) from an island in the lower Danube floodplain. Alytes, 15,145-157. Castanet, )., H. Francillon-Vieillot, F. }. Meunier & A. De Ricqies (1993): Bone and individual aging. In: Hall, B.K. (ed.)r Bone. CRC Press, Boca Raton, Florida, 245-283. Dunham, A. E. & D. B. Miles (1985): Patterns of covariation in life history traits of squamate reptiles: the effects of size and phylogeny reconsidered. Am. Nat., 126, 231-257. Otukit, G. & G. Pasuljevii (1983): On chorological demarcation of the species Pelobates fuscus (Laurenti) 1768 and Pelobates syriacus Boettger 1889 (Amphibia, Pelobatidae) in Yugoslavia. I. Zoogeographical study. Proceedings of the Second Symposium of Fauna Serbia, 139-142 (in Serbian with English abstract). Eggert, C. & R. Guyelant (1999): Age structure of a spadefoot toad Pelobates fuscus (Pelobatidae) population. Copeia, 4, 1127-1130. Faii-bairn, D. jL (1997): Allometry for sexual size dimorphism: pattern and process in the coevolution of body size in males and females. Ann. Rev. Ecol. Evol., 28, 659-687. 119 ANNALES • Ser. hist. nat. -11- 2001 1 (23) Irena ROT NIK¿£VI one climatic cycle) lake sediment records from Pamvotis (W. Greece) and Kopais (E. Greece). These analyses provide additional insights into the temporal structuring of aquatic biodiversity and the timing of colonisation events. Contrasts are also made with faunistic and paiaeoecoigica! datasets from adjacent regions - notably western Anatolia. Key words: Ostracoda, Quartemary, recent, palaeobiogeography, southern Balkans 10 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts Interdisciplinary Workshop "Pattern and Process in Saltan Biodiversity", Koper, September 2,5-28 200"! DIATOMS AS BIODIVERSITY INDICATORS IN LAKES OF THE CIRCUM-MEDJTERRANEAN Jane M. REED Department of Geography, University of Hull, UK Diatoms (single-celled siliceous algae) occur in virtually all water bodies, are abundant, diverse and sensitive to a wide range of water chemistry variables. In lake sediment studies of past environmental change, their power as highly sensitive monitors of temporal trends in environmental variables such as salinity (related to lake-level and climate change) or nutrient status is widely acknowledged. Over the past decade diatom research has advanced considerably, with the development of transfer functions based on large modern regional data-sets of water chemistry and diatom assemblage composition data, from which to quantify past changes in water chemistry variables. The Mediterranean regions of the Balkans, Turkey and Spain contain a wide variety of wetlands, including fresh (hydrologically open) and saline (hydrologically closed) lakes. Many of these wetlands are threatened increasingly by the effects of human-induced eutrophication and accelerated water abstraction, such that issues surrounding conservation and biodiversity are of particular concern. Whilst existing diatom-based research has been aimed primarily at reconstructing past environmental change, the recent expansion of diatom study in these regions has produced for the first time large regional data-sets of modern ecological data and an increasingly large body of long (last c. 10-20,000 yr.) and short (last c. 150 yr.) term pafaeolimnologicai data, from which to assess temporal trends in biodiversity, both on a site-specific and regional basis. This paper explores the potential of diatoms as indicators of biodiversity in the circ.um-Mediterranean, based on modern ecological and palaeoecological studies of fakes of the Balkans, Turkey and Spain, and by comparison with previously published species inventories for particular lakes. The influence of taxonomic nomenclature, habitat variation and sampling site on apparent biodiversity is discussed, and temporal trends are assessed using simple biodiversity indices. It is suggested that one of the most valuable outcomes of using the long-term palaeolimnologi-cal record to assess biodiversity, by reference to large modern ecological data-sets, is that one may identify clearly the past existence of characteristic diatom assemblages (and by inference, lacustrine environments) which now have no modern analogue in the regional flora. Key words: diatoms, Mediterranean, palaeolimnology, biodiversity, transfer functions 11 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts interdisciplinary Workshop "Pattern and Process in Balkan Biodiversity", Koper, September 25-20 2001 CRYPTIC SPECIATION IN DINARIC KARST WATERS: MOLECULAR APPROACHES REVEAL A NEW DIMENSION OF DIVERSITY Peter TRONTELJ, Rudi VEROVNIK & Boris SKET Department of Biology, University of Ljubljana, Slovenia The aquatic fauna of the Dinaric karst area of the western Balkan Peninsula is renowned for its endemism and high diversity. This species richness is chiefly due to a high number of specialists inhabiting different types of subterranean waters, karst springs, resurgences, sinking rivers and other types of karst waters. Particularly rich groups with many endemic species can be found among crustaceans (e.g. amphipods, isopods, copepods), gastropods (e.g. Hy-drobioidea), leeches (Erpobdeifidae) and fishes (Cyprinidae). Many of these taxa live only in small, restricted areas, especially the subterranean or stygobitic species. The Dinaric region is known to hold the richest stygobitic fauna in the world. However, little is known about the processes and historical events that shaped such a rich fauna. In contrast to many highly endemic, restricted-range-species, there are a number of widely distributed species occupying the same habitats. They are often morphologically homogeneous across their entire range. Examples of such taxa are the blind cave salamander Proteus anguinus, the cave shrimp Troglocaris "anophthatmus", the tube worm Marifugia cavatica and the leech Dina lineata. It has already been suggested that each of them might in fact represent a diverse species aggregate. The genetic patterns of their diversification might provide clues to the specia-tion process in karst waters. Initial molecular genetic studies were conducted on Dina lineata, Asellus aquaticus and Proteus anguinus. Nuclear ribosomal ITS sequences, mitochondrial ribosomal genes and RAPDs have been employed as molecular markers. One of the most striking results of these studies was the high degree of isolation between neighboring populations. Adjacent populations of D. lineata differed from one another in their ITS2 sequences even more than some closely related erpobdeliid species from each other. No gene flow could be detected between them. The most probable factor causing this isolation is the specific hydrography of karst waters. During the karstification process, rivers and other water bodies became fragmented in an island-like manner. The original dispersion must have taken place prior to extensive karstification, when the dispersion pathways were still present. The cryptic speciation of D. lineata can thus be explained by a series of vicariant events. A similar scenario may hold for most of the widely distributed genera with many endemic species and subspecies. The case of troglomorphic forms of Asellus aquaticus demonstrates that the speciation processes can be more complex when it is linked to the invasion of caves. RAPD data have revealed that the stygobitic A. a. cavernicolus from Planina Cave does not interbreed with surface populations, with which they have potential physical contact. A second stygobitic population in the subterranean R. Reka some 30-ktn away clearly arose from an independent cave invasion. Moreover, a third, only partially troglomorphic population is known from the Postojna-Planina cave system. It arose from a more recent invasion and does not interbreed with the fully troglomorphic populations in the same system. The temporal, not the spatial component of isolation played the main role in producing this unique case of sympatric occurrence of two independent troglobitic descendants of the same surface species. One can conclude that molecular genetic data have confirmed some predictions about the diversity patterns of aquatic animals of the Dinaric karst, like (1) the existence of cryptic species and (2) multiple independent steps of a single ancestral species towards a subterranean lifestile. They further provided evidence that vicariant habitat fragmentation events played a major role in the formation of species richness. Key words: speciation, hypogean fauna, Proteus, Asellus, molecular biology 12 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts Interdiseipifnary Workshop "Pattern and Process in Balkan Biodiversity", Koper, September 25-26 2.001 PHYLOGENY AND BiOGEOGRAPHY OF ADRIATIC LIZARDS - A CONTRIBUTION TO THE DINARIC (WESTERN BALKAN) PHYLOGEOGRAPH1C SCENARIO Martina PODNAR, Werner MAYER, Nikola TVRTKOVlC and Eduard KI.ETECKI Croatian Natural History Museum, Zagreb, Croatia The flora and fauna of the Adriatic coast and especially its islands is under a strong antropogenic influence that caused extremely large Holocene changes in its composition. Thus, all data that still can be obtained from natural population remnants are of major importance. Together with the fossil and sub-fossil records, they can be used to reconstruct the history of colonisation of the Dinaric Kg ion. The distribution of endemic subspecies, and some congruent patterns of intraspecific variability imply the existence of the two main centres of diversity for the mainland species: one located at the region of Kvarner and a second in Dalmatia. These regions probably were also two distinct glacial réfugia. The fact that today as many as 12 lacertid species inhabit the east Adriatic coast opens the possibility, through a phylogeographic approach, for a significant contribution to the general knowledge about the history of colonisation of this area. Preliminary results of investigations of Adriatic populations o/'Podarcis sicula and P. melisellensis based on the analysis of mitochondrial {mtDNA} markers will be presented. The contribution of these data to the elucidation of the colonisation pathways during and after the Pleistocene will he discussed. Some old, already forgotten records, as well as some new ones will be highlighted. Key words: speciation, islands, phylogeny, lizards, Lacertidae 13 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts interdisciplinary Workshop "Pattern and Process in Balkan Biodiversity", Koper, September 25-26 200Ï BIVALVE MOLLUSCS FAUNA OF ANCIENT LAKES IN THE CONTEXT OF HISTORICAL BIOGEOGRAPHY IN THE BALKAN REGION Alexei V. KORNIUSHIN international Solomon University, Kiev, Ukraine Ancient lakes with their unique plant and animal communities are well known as "hot spots" of biodiversity and refuges for relict faunas. Therefore, investigations of these peculiar habitats are important for biogeographical régionalisation, the reconstruction of fauna! history and understanding the mechanisms of speciation (StankoviC 1960). Among animal groups, gastropod molluscs are distinguished by the great diversity of endemics in some ancient lakes (Baikal, Tanganyika and Ohrid) and the presence of high rank endemic taxa (families/subfamilies in the first two lakes, gen-era/subgenera in the latter). Bivalve mollusc taxa seem to be more conservative and widespread, but nevertheless family Sphaeriidae is represented by endemic species and subspecies in Baikal, Ohrid, Prespa, Biwa, the African Great Lakes and Titicaca (see Korniushin et al. (2000) for a review), and a number of endemic Corbicuia species are known from the ancient lakes of Sulawesi, Indonesia. All endemic lacustrine bivalves belong to widely distributed genera, except the unique cemented bivalve from Lake Poso included in a separate genus (family Corbiculidae). At present, twelve species of bivalves are known from Lake Ohrid and five from Lake Prespa (Dhora & Weiter-Schultes, 1996; Korniushin, unpubl.). Most of them have broad Palaearctic or European ranges, the recent distribution of Microcondylaea compressa (Menke, 1830) is basically Mediterranean. Two endemic species (Pisidium ed-laueri Kuiper, 1960 from Ohrid and P. maasseni Kuiper, 1987 from Prespa) proved to be close relatives of the Holarctic P. nitidum Jenyns, 1832 (Korniushin et ai., 1998). Pisidium subtruncatum Maim, 1855 is represented in Ohrid by an endemic subspecies. Noteworthy, such species as P. amnicum (Muller, 1774), P. henslowanum (Shep-pard, 1823), P. moitessierianum Paladilhe, 1866 (all found in Ohrid), as well as P. nitidum jenyns, 1832 are now represented in the Balkans by scarce, isolated populations. Composition of the bivalve mollusc fauna in Ohrid and Prespa does not contradict the biogeographical concept of StankoviC (1960) which suggests the origin of the lake's fauna from the freshwater fauna distributed across Eurasia in Tertiary. However, the group P. (Odhneripisidium) apparently having its roots in this ancient fauna is represented in Ohrid by only one species - P. tenuilineatum Stelfox, 1918, sporadically distributed in other European countries, while P. annandalei sensu Kuiper, 1962 (~ P. sogdianum Izzatullaev & Starobogatov, 1986) is restricted in the Balkans to Greece. The taxonomy of Dreissena in the Balkan region is rather intricate. In particular, the Ohrid form was once described as a new species and even included in a separate subgenus (Lvova & Starobogatov, 1982), but modern reviewers treat it as a variety of D. polymorpha (Pallas, 1771) (Dhora & Welter-Schultes, 1996). While Ponto-Caspian origin of Dreissena is evident, the exact sources for its invasion in the Balkan region need to be clarified by the further morphological and molecular studies. Our study shows no testable relationship between the bivalve faunas of Ohrid and Prespa. Similarity between P. subtruncatum recalvum Kuiper, 1960 from Ohrid and the form of the same species living in Prespa (Korniushin et ai, 2000) can be explained by convergence, since similar characters (high triangular shell and broad hinge plate) develop independently in many lacustrine taxa. Thus, the Balkan lakes are rather peculiar in respect of their bivalves, even if compare them to the older lakes with the higher general level of endemism, like Baikal and Tanganyika. However, biogeographic information provided by these molluscs is limited because of their low diversity and wide distribution. Revision of the extremely diverse Ohrid gastropods (71 species) by using exact methods of phylogenetic reconstruction including molecular phylogenetics seems to have great potential in this respect. Key words: Moliusca, bivalves, ancient lakes, speciation, Ohrid, Prespa References: Dhora, Dh. & F. W. Welter-Schultes (1996): List of species and atlas of the non-marine molluscs of Albania. Schriften zur Malakozoobgie, 9, 90-197. Korniushin, A. V., Z. Krstanovski & G. Kostoski (2000): Anatomical evidence of close affinity between endemic species of Pisidium (Bivalvia, Sphaeriidae) from some ancient lakes and the widely distributed taxa, journal of zoological systematics and evolutionary research, 38(2), 81-86. Lvova A. A. & Y. I. Starobogatov (1982): New species of Dreissena (Bivalvia: Dreissenidae) from Lake Ohrid. Zo-ologicheskij Zhurnal, 61(11), 1749-1752. Stankovk, S. (1960): The Balkan Lake Ohrid and its living world. Monographiae Biologicae, 9. Dr. W. junk, den Haag- 14 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts Interdisciplinary Workshop "Pattern and Process in Balkan Biodiversity", Koper, September 25-20 2001 DIVERSITY OF AMPHIBIANS AND REPTILES ON THE BALKAN PENINSULA Georg DŽUK1Č Institute for Biological Research "Stniša Stankovih", Belgrade, FR Yugoslavia Miloš L. KALEZIČ Institute for Biological Research "Siniša Stankovih", Belgrade, FR Yugoslavia and Institute of Zoology, Belgrade, FR Yugoslavia The Balkan amphibians and reptiles are diversified in many respects. First of all, there is an enormous species-richness in the Balkan Peninsula. Approximately 100 species of these vertebrates live in this part of Europe, with also the realistic possibility of the existence of a number of morphologically cryptic taxa. Secondly, batrachofauna (amphibians) and herpetofauna (reptiles) of this part of Europe has diverse bio-geographical origins and connections with other regions. Namely, the Balkans appear to have been centre of intensive speciation within some taxa. There is evidence that new species emerged during Tertiary (mostly Miocene and Pliocene), whilst subspecies origin was confined to the Pleistocene. Furthermore, there were intense migrations of amphibians and reptiles from other zoogeographicai areas via two main migration routes (the Pontic Bridge and mostly the Morava River Corridor). In the first place, there is a large front of contact with steppes to the east and northeast, whilst the Aegean islands constituted a connection with the African and Asian fauna, in addition, in contrast to the Iberian and Apennine peninsulas, the Balkan Peninsula is not separated by a mountain barrier from the European mainland, and thus is widely connected with central Europe and therefore, the rest of continent. This has crucial importance for the European batracho- and herpetofauna, because it has been shown that central and northern Europe were populated by expansions from a Balkan refugium in the Holocene. Also, some groups have withdrawn from northern and mid European latitudes, some of them now being restricted to southern refugial areas. On zoogeographicai grounds, the Balkan Peninsula is also characterised by numerous discontinuities; i.e. the zoo-geographical map is very complex with elaborate subdivisions, as well as with a wealth of preglacial fauna! elements. Also, this area is the strongest centre of reptile and amphibian endemnicity in Europe, with the more than 45 endemic species, and many relict taxa. Due to these facts, some parts of the Balkans, in particular the Adriatic triangle (broadly speaking Prokletije Mt- area), are recognised as being one of Europe's main biogenetic reserves. As these isolated populations are mostly at species' range limits, there are numerous cases of range shrinking in the Balkan area. Of all species living in Balkans, 53% have range limits there. Although most of these peripheral populations are not going to evolve into distinct entities, there is still an astonishing potential for further evolutionary diversification. In terms of general biological phenomena, Balkan amphibians and reptiles usually have much more inter- and intrapopufation genetic variability (in terms of allelic variation and a number of distinct genomes) when compared with other European areas. Diverse types of hybridisation and intergradation zones, which are differently spatially orientated (N-S, NW-SE directions, vertical distribution), are common on the Balkan Peninsula. Interspecific and in-traspecific heterochronic phenomena expressed as a retention of ancestral larval features by a reproductively mature adult descendent (paedomorphosis and paedogenesis, respectively) are common among Balkan tailed amphibians. Paedomorphosis characterises the only European real cryptobiont (Proteus anguinus), while the existence of alternative life-history pathways among individuals of the same population (paedogenesis) is extremely high in Balkan newts (Triturus), especially along the Dinaric Alps. Also, it seems that hybridogenesis occurs in a number of green frog complexes (Rana kleptons), more than elsewhere. Finally, as in other places in Europe, there are more reproductive modes (oviparity vs. viviparity) within a single species (Lacerta vivipara). In general, genesis of the present day diversities of the Balkan amphibians and reptiles was influenced by numerous factors, e.g. habitat heterogeneity, topographic diversity (mostly influenced by Pleistocene glaciations), great variation in climate, differences in rates of immigration, evolutionary and ecological time, etc. It should be stressed that geological history and palaeogeography of the Balkan Peninsula has undergone complex perturbations, especially during the Tertiary. Also, there is a correspondence of zoogeographicai boundaries with the distribution of deep lithospheric breakages (crustal megablocks), so that these geological events might profoundly effect the evolutionary history at least of some Balkan amphibians (e.g. Triturus cristatus superspecies). However, for a more comprehensive picture of Balkan amphibians and reptiles we still lack many relevant data on longstanding taxonomic problems, population structure, distributional characteristics of some taxa (size, shape, boundaries, overlaps and locations of geographic ranges), especially those which can be considered as a "zoo-geographic paradoxes" (occurrence of isolated populations in "unexpected places"). Also, historical biogeographical patterns remains almost unexplored thus far, including the phylogenetic relationships of species and, especially, taxon-area cladograms. Key words: reptiles, amphibians, evolution, diversity, tectonics 15 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts Interdisciplinary Workshop "Paitern and Process in Balkan Biodiversity", Koper. September 25-28 2001 A ZOOGEOCRAPHICAL REVIEW OF THE SPIDERS (ARANEAE) OF THE BALKAN PENINSULA Christo DEL T5HEV Institute of Zoology of the Bulgarian Academy of Sciences, Sofia, Bulgaria According to their current distribution, the over 1,400 established spider species can be classified into 24 zoo-geographical categories, grouped into 4 complexes (widely distributed, European, Balkan endemic and Mediterranean). The largest number of species belongs to the widely distributed complex, but the most characteristic are the Balkan endemics. The established number (389) in the latter category is high and reflects the local character of the fauna. In the context of palaeoenviromental changes since Pliocene, this phenomenon can be attributed to the relative isolation of the mountains compared to the lowlands. Moreover, the high percentage representation of endemics suggests an important process of autochthonous speclation. Thus, the Balkan Peninsula can be considered as being a major centre of speciation for the European araneofauna. Key words: spiders, diversity, endemicity, Bulgaria, speciation MAMMAL BIODIVERSITY IN THE BALKANS Boris KRYSTUFEK Slovenian Museum of Natural History, Ljubljana, Slovenia Mediterranean Europe is known to be a host of endemic taxa in general and in rodents In particular. In compari-sion with the remaining peninsulas (the Iberian and the Italian), the Balkans are particularly rich in both phyloge-netic and biogeographic relics. It has been shown that the hot spots of European rodent diversity are focused in the Balkan Peninsula (including the Carpathian Basin) and adjacent parts of southern Ukraine and Ciscaucasia, where >80% of rodent genera and species occur on merely 11.4% of the continent's surface (Krystufek & Griffiths, in press). Among the eight mainland European rodents with particularly restricted distributional ranges (range encompassing <1% of the continent's surface), no less than five are from the Balkans (Mesocricetus newtoni, Dinaromys bogdanovi, Microtus felteni, M. tatricus, Miomymus roachij, and a number of other species have similarly narrow ranges (e.g. Spermophiius citellus, Nannospalax arenarius, Microtus thomasi, Apodemus mystacinus s. s.). Due to high chromosomal polymorphism in some taxa on one hand (particularly Nannospalax leucodon, but also Sorex araneus and Microtus thomasi) and a lack of comprehensive taxonomic treatments on the other, the number of taxa with very restricted ranges is likely to be higher than actually recognised- In addition, the island of Crete hosts two island endemics (Crocidura zimmermani, Acomys nesiotes) out of the three documented for Europe. This accords with the-oft suggested role of the Balkans as a Quaternary refugium - based on its age as a distinct landscape unit and also because of complex Plio-Pleistocene vicariant interactions between the Balkans and Anatolia. In general, mammalian spatial patterns have been poorly documented and studied - e.g. Mediterranean small mammal communities are less species rich than are continental ones, and the transition between the two lies at c. 700-900 m on the Dinaric Alps (north-western Balkans; KryStufek & Griffiths, 1999). Mustelids show a monotonous latitudinal decline in a-diversity, with their highest values in the Carpathian Basin (Krystufek, 2000). Key words: mammals, refugia, biodiversity, authochthony References: KryStufek, B. (2000): Mustelids in the Balkans - small carnivores in the European biodiversity hot-spot, in: Griffiths, IT. I. (ed.): Mustelids in a modern world. Management and conservation aspects of small carnivore: human interactions, Backhuys Publishers, Leiden, pp. 281-294. KryStufek, B. & H. I. Griffiths (1999): Mediterranean v. continental small mamma! communities and the environmental degradation of the Dinaric Alps, j. Biogeography, 26, 167-177. KryStufek, B. & H. I. Griffiths (in press): Species richness and rarity in European rodents. Ecography. 16 ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts Interdisciplinary Workshop "Paaern and Process in Balkan Biodiversity", Koper, September 25-28 2001 THE BJOGEOGRAPHY OF PRESPA: KNOWLEDGE AND IGNORANCE Giorgos CATSADORAKIS Society for the Protection of Prespa, Prespa, Greece in this paper! use biogeographic statistics referring to piants and several animal orders found in the Greek part of the Prespa area, and compare these with data from other well-studied areas in Greece and neighbouring Balkan countries. Data used concern vascular plants, monogenean fish parasites (piatyhelminths), land snails, orthopteran insects, freshwater fishes, reptiles and birds, with the overall objectives of clarifing unclear issues, and highlighting up critical questions and gaps in our fundamental knowledge of the biogeographic particularities of this valuable area, that is characteristic of the central Balkans, In addition to the above data i also use data concerning distribution ranges of specific plant and animal species, geological and archaeological data and breeding performance parameters of certain bird species. Drawing very concrete biogeographic conclusions in such an area at the transitional zone between Continental Europe and Mediterranean is as difficult as it is interesting. Although the area is most probably one of the best studied in the Balkans, the amount of available scientific data is still poor in comparison to many places in north and central Europe. Key words: biodiversity, conservation, Prespa, Greece MICRO AND MACROSCALE DIVERSITY OF COPEPODS IN THE SUBTERRANEAN REALM OF SLOVENIA Anton BRANCELJ National Institute of Biology, Ljubljana, Slovenia Tanja PIPAN Karst research Institute ZRC SAZU, Postojna, Slovenia Copepoda (Crustacea) are one of the most widely distributed groups of organisms in the World, ranging from free-living zooplankters to ecto- and endoparasites of a wide variety of aquatic organisms. Copepods inhabit high-mountain waters and deep-sea floor. Ail over the world subterranean environments are inhabited by numerous co-pepod taxa, and many of these are endemics. One of the richest areas for endemic subterranean copepods is the Di-naric area of SE Europe. In Slovenia (as the most north-westerly part of the Dinaric region) about 110 copepod taxa have been recorded, about half of which are stygobionts. At the moment there are about 20 endemics known - all but one are stygobionts belonging to the group Harpac.ticoida. In recent years, intensive research on Slovenia's cave-dwelling copepods in caves has revealed a high number of taxa inhabiting percolating waters and adjacent pools. In these environments at least nine species new to science have been recognised. In total, 38 taxa were collected in seven horizontal caves (length = 75 m ~ 1 km). Of these, ten taxa could be designated as ubiquitous as they are found frequently in the subterranean environment, but after transport from epigean habitats, however, the rest are stygobitic and fourteen are endemics to Slovenia. This results in high density of endemics in an area of about 2,400 km2, i.e. 1 taxon/170 km2. Between 11-17 different copepod taxa found per cave, regardless of its length (the 75 m cave featured 12 taxa, whilst 13 and 17 taxa were recorded from two caves > 1 km). Of 38 taxa only one (Speocyciops infernos) was found in all seven caves, whilst two more (genus Parastenocaris) were present in six caves. Fourteen taxa were found only at one location and seven of them were ubiquitous taxa, transported into the caves by accident; the rest were stygobitic taxa. The high total number of taxa found in the caves, the high numbers of taxa per cave (11-17) with a dominance of stygobitic taxa, and the very low number of taxa common to all caves, indicate that biodiversity in subterranean environment is very high at both local and wider scales. This also suggests that some species still remain to be discovered in this environment. Key words: cladocera, hypogean, endemicity, species richness, Slovenia 17 ANNALES Ser. hist. nat. 11. 2001 ■ Suplemcnt - Abstracts interdisciplinary Workshop "Pattern a:>d Process in Balkan Biodiversity", Koper, September 25-28 200! FACTORS AFFECTING THE DIVERSITY OF THE ADRIATIC ICHTHYOFAUNA Lovrenc LIPE] Marine Biological Station - National institute of Bioiogy & ZRS Koper, Koper, Slovenia Jakov DULCJC Institute of Oceanography & Fisheries, Split, Croatia The Adriatic comprises an independent biogeographica! and ecological subunit of the Mediterranean owing to peculiarities evident from the composition properties of its life communities (biocenosis). During the past ten years several papers have been published on the occurrence of new fish species in Adriatic waters, bringing the number of fish species in the Adriatic Sea to 417 in 1 "5 9 families (i.e. 72% of the species and subspecies known in the Mediterranean). The new records are mostly of thermophilic species. The movement of these species is also cited as evidence for the warming of Mediterranean waters. The greatest part of the south Adriatic basin has not been sufficiently explored as regards its ichthyofauna, particularly not at depths of >500 m. Most species and subspecies of Adriatic fish, apart from some endemic species (6) and subspecies, belong to the Mediterranean and Mediterranean-Atlantic biogeographic region. During the fast decades the number of thermophilic species in the Adriatic increased, mainly due to the effects of oceanographic changes. Some Lessepsian migrants were also reported in the Adriatic in recent years. On the other hand some native and even endemic species became endangered due to certain anthropogenic factors, notably uncontrolled fishing, eutrophication and different kinds of pollution. Key words: fish, Adriatic, diversity, origins, conservation 18 Za izdaje Annales so prispevali še; mrnam S" primorske S, norice Telekom^ Slovenije v tiskarna ljubljana, d. 1000 ljubljana, tržaška 42, SLOVENIJA telefon: 01/423 15 15,?eiefax:01/423 4t 23