117 Tr`a{ki zaliv – mednarodno morsko obmo~je IBA / SPA? The Gulf of Trieste – an international marine IBA / SPA site? Pri dosedanji mre`i obmo~ij IBA, ki jo je vzpostavila organizacija BirdLife International in je v Evropi tudi podlaga za dolo~anje obmo~ij SPA v okviru omre`ja Natura 2000 (Heath & Evans 2000), se je pokazalo nekaj pomanjkljivosti, ki ka`ejo na nezadostnost pri uspe{nem varstvu nekaterih vrst ptic. Mednje sodijo morske ptice, saj pravega morskega obmo~ja IBA ni med obmo~ji, ki jih je definiral BirdLife International. S strani organizacije je bila speljana pobuda, imenovana Globalni program za morske ptice (Global Seabird Programme), ki naj bi zapolnila to vrzel. Naloga programa naj bi bila identifikacija morskih obmo~ij IBA, pri ~emer so bili oblikovani {tirje glavni tipi le-teh (Carboneras & Requena 2006): (1) morske raz{iritve obstoje~ih IBA-jev z gnezditvenimi kolonijami morskih ptic (prehranjevali{~a v radiu 5, 15 ali 40 km); (2) obalne negnezde~e koncentracije ptic (gre zlasti za agregacije nekaterih kopenskih vrst na morju, denimo slapnikov Gavia sp., ponirkov Podiceps sp., rac Anatidae ipd.); (3) selitvena ozka grla (predvsem morske o`ine, kjer se selijo ogro`ene in potencialno ogro`ene morske ptice); (4) prehranjevali{~a zunaj dosega gnezde~ih kolonij (gre predvsem za obmo~ja, bogata s hrano, kjer prihaja do ve~jih agregacij morskih ptic). V Sredozemlju, ki obsega tudi manj{i ko{~ek slovenske obale, je bil sprejet splo{ni pristop k varstvu te razmeroma ob~utljive in dokaj obremenjene morske regije. Za 15 ogro`enih morskih ptic je bil v II. dodatku Barcelonske konvencije izdelan akcijski na~rt (UNEP MAP RAC/SPA 2003). V Sloveniji in na slovenskem morju naj bi se po doslej znanih in zbranih podatkih pojavljalo kar 14 vrst s tega seznama, med njimi na Obali, vsaj v zadnjem ~asu, sedem vrst razmeroma redno (Vrezec 2006): sredozemski viharnik Puffinus yelkouan, vranjek Phalacrocorax aristotelis desmarestii, pritlikavi kormoran Phalacrocorax pygmeus, ribji orel Pandion haliaetus, bengalska ~igra Sterna bengalensis, kri~ava ~igra Sterna sandvicensis in mala ~igra Sternula albifrons. Narejena je bila analiza populacijskih ocen vrst glede dele`a sredozemske oziroma svetovne populacije teh ptic, ki se v slovenskem morju relativno redno zadr`ujejo bodisi na gnezditvi, poleti na prehranjevali{~ih ali pozimi na prezimovali{~ih (podatki primerjani z ocenami po Burfield & van Bommel 2004). Ob tem sta se z visokim dele`em (>1%) svetovne populacije izkazali dve vrsti, in sicer sredozemski viharnik (do 1.5%) in vranjek (do 11.4%), pri slednjem gre za endemi~no sredozemsko podvrsto Ph. a. desmarestii, ki ima edina status naravovarstveno pomembnega taksona (Vrezec 2006). Pri obeh vrstah pa gre za prete`no poletne agregacije ptic na prehranjevali{~ih v razmeroma plitvem in s hrano bogatem morju Tr`a{kega zaliva, kamor sodi tudi slovensko morje. Sredozemski viharnik se na obmo~ju jeseni pojavlja v velikih jatah do 1000 osebkov, kar so najve~je agregacije vrste v Jadranskem morju (zbrano v Stip~evi} & Luka~ 2001). V poletno-jesenskem ~asu se na prehranjevali{~ih v Tr`a{kem zalivu zbere izredno velika populacija vranjekov, po ocenah 1500−2000 ptic (Benussi 2005), kar je verjetno dobra polovica vse jadranske populacije (Burfield & van Bommel 2004). Gledano v celoti, Tr`a{ki zaliv s svojim slovenskim in italijanskim delom Acrocephalus 27 (130/131): 117−129, 2006 118 izpolnjuje kriterije za ~etrti tip morskega obmo~ja IBA, saj je prehranjevali{~e pomembnega dele`a svetovne populacije sredozemskega viharnika in sredozemske podvrste vranjeka. Te`ava pri tem je, da je obmo~je razdeljeno med dve dr`avi, zato bi moral obstajati dogovor med obema stranema o obojestranski razglasitvi mednarodnega morskega obmo~ja IBA. ^eprav, kot ka`e, obmo~je izpolnjuje kriterije, pa je vendar naloga tako slovenskih kot italijanskih ornitologov, da pripravijo ustrezne strokovne podlage, varstvene smernice in hkrati s tem pobude za formalno razglasitev obmo~ja IBA, ki bi po kriterijih BirdLife International sodilo tudi na seznam obmo~ij SPA znotraj omre`ja Natura 2000. Tesno mednarodno sodelovanje je v tem primeru ve~ kot nujno in potrebno! *** The BirdLife International has developed a net of IBA areas, which is also fundamental for declaring SPA areas in Europe in the scope of the Natura 2000 network (Heath & Evans 2000). However, there are some gaps that do not allow all the needs for successful bird conservation to be fulfilled. One is conservation of marine birds, as no real marine IBAs have been declared so far. Therefore, BirdLife International developed a Global Seabird Programme for resolving the problem. The main task of the programme is to identify marine IBA areas, where three distinct types are considered (Carboneras & Requena 2006): (1) Seaward extensions of marine bird breeding colonies in the existing IBAs (foraging areas in radii of 5, 15 or 40 km); (2) Coastal concentrations of non-breeding birds (aggregations of some waterbirds at sea, e.g. divers Gavia sp., grebes Podiceps sp., ducks Anatidae etc.); (3) Migration bottlenecks of threatened and potentially threatened marine birds; (4) Non-contiguous foraging areas (areas rich with food far from breeding colonies, where larger flocks of marine birds aggregate). In the Mediterranean, including the Slovenian coast and sea, a general consensus has been accepted for conservation of this relatively sensitive and heavily influenced sea region. According to Appendix II of the Barcelona Convention, an action plan was prepared for 15 threatened marine bird species (UNEP MAP RAC/SPA 2003). 14 species from this list have been recorded in Slovenia. Among them, seven species have been regularly frequenting the coast in recent years (Vrezec 2006): Mediterranean Shearwater Puffinus yelkouan, European Shag Phalacrocorax aristotelis desmarestii, Pygmy Cormorant Phalacrocorax pygmeus, Osprey Pandion haliaetus, Lesser Crested Tern Sterna bengalensis, Sandwich Tern Sterna sandvicensis, and Little Tern Sternula albifrons. An analysis of population size estimates was conducted in terms of the proportion of birds of the respective global populations breeding, wintering or foraging relatively regularly in the Gulf of Trieste, including the Slovenian sea (compared to Burfield & van Bommel 2004). Those whose proportion of their global population was high (>1%) were the Mediterranean Shearwater (up to 1.5%) and Shag (up to 11.4%; Vrezec 2006). In the latter species, only the endemic Mediterranean subspecies Ph. a. desmarestii was taken into consideration, as it is the only taxa of the species of conservation importance. Both Mediterranean Shearwater and Shag exhibited dense summer aggregations in foraging Uvodnik / Editorial 119 areas of the relatively shallow and rich Gulf of Trieste. The Mediterranean Shearwater is especially abundant in the autumn, when large flocks of up to 1,000 individuals forage in the area, which are the largest flocks recorded in the Adriatic Sea (Stip~evi} & Luka~ 2001). A large aggregation of Shags also forages in the area in the summer-autumn time with an estimated population of 1,500−2,000 birds (Benussi 2005), which is probably nearly a half the entire breeding population in the Adriatic Sea (Burfield & van Bommel 2004). Given these data, the Italian and Slovenian parts of the Gulf of Trieste area, together fulfil the criteria for the fourth marine IBA type as a foraging area for an important part of the global population of the Mediterranean Shearwater and Mediterranean subspecies of the European Shag. The major problem lies in the fact that two countries contribute to the area, while a common agreement in declaring an international marine IBA area needs to be made. Slovenian and Italian ornithologists should jointly prepare the requisite scientific background issues, conservation guidelines and initiatives for a formal declaration of a new IBA area, which would according to BirdLife International criteria also be considered as an SPA site in the Natura 2000 network. Close international cooperation is therefore more than needed in this respect! Al Vrezec Literatura / References: Benussi, E. (2005): Marangone dal ciuffo Phalacrocorax aristotelis (Linnaeus, 1761). pp. 117−118 In: Guzzon, C., Tout, P. & Utmar, P. (eds.): I censimenti degli uccelli acquatici severnanti nelle zone umide del Friuli Venezia Giulia, Anni 1997−2004. – Associazione Studi Ornitologici e Ricerche Ecologiche del Friuli-Venezia Giulia (A.S.T.O.R.E. − FVG), »Centro Stampa« di A. Candito & F. Spanghero Snc, Monfalcone. Burfield, I. & van Bommel, F., eds. (2004): Birds in Europe: population estimates, trends and conservation status. BirdLife Conservation Series No. 12 − BirdLife International, Cambridge. Carboneras, C. & Requena, S. (2006): Important bird areas at sea (marine IBAs) − where we are & next steps. pp. 22−24 In: Aransay, N. (ed.): Proceedings of the first symposium on the mediterranean action plan for the conservation of marine and coastal birds. Vilanova i la Geltrú (Spain), 17−19 November 2005, RAC/SPA pub., UNEP − MAP − RAC/SPA, Tunis. Heath, M.F. & Evans, M.I., (eds.) (2000): Important Bird Areas in Europe: Priority sites for conservation. BirdLife Conservtion Series No. 8 − BirdLife International, Cambridge. Stip~evi}, M. & Luka~, G. (2001): Status of tubenose seabirds Procellariiformes breeding in the eastern Adriatic. − Acrocephalus 22 (104/105): 9−21. UNEP MAP RAC/SPA (2003): Action Plan for the Conservation of bird species listed in Annex II of the Protocol concerning Specially Protected Areas (SPAs), and Biological Diversity in the Mediterranean. − RAC/SPA pub., UNEP − MAP − RAC/ SPA, Tunis. Vrezec, A. (2006): Marine and coastal birds of Slovenia: status, population size and conservation of Mediterranean action plan species. pp. 81−85 In: Aransay, N. (ed.): Proceedings of the first symposium on the mediterranean action plan for the conservation of marine and coastal birds. Vilanova i la Geltrú, (Spain), 17−19 November 2005, RAC/SPA pub., UNEP − MAP − RAC/SPA, Tunis. Acrocephalus 27 (130/131): 1−3, 2006