received: 2022-03-29 DOI 10.19233/ASHN.2022.19 
IMPROVEMENT OF THE ECOLOGICAL STATUS OF THE CYMODOCEA NODOSA MEADOW NEAR THE PORT OF KOPER 
Martina ORLANDO-BONACA 
Marine Biology Station Piran, National Institute of Biology, SI-6330 Piran, Fornace 41, Slovenia e-mail: martina.orlando@nib.si 
Erik LIPEJ 
Ulica XXX divizije 10, SI-6320 Portorož, Slovenia 
Romina BONACA 
Ulica Vena Pilona 5, SI-6000 Koper, Slovenia 
Leon Lojze ZAMUDA 
Marine Biology Station Piran, National Institute of Biology, SI-6330 Piran, Fornace 41, Slovenia 
ABSTRACT 
Seagrass beds are more or less the marine counterpart of tropical rainforests, and their health is related to different anthropogenic stressors, including navigation routes and port activities. In the Mediterranean Sea, Cymodocea nodosa is considered an effective indicator of environmental change, due to its univer­sal distribution, sensitivity to various natural and anthropogenic pressures, and the measurability of the species’ responses to impacts. The aim of this study is to present the changes in the assessment of the ecological status of the C. nodosa meadow near the port of Koper, which was evaluated as Bad in 2018. The results show a significant improvement in the ecological status of the meadow, which can be attributed to a reduction in anthropogenic stressors. 
Key words: Cymodocea nodosa, status evaluation, MediSkew index, Port of Koper, northern Adriatic Sea 
MIGLIORAMENTO DELLO STATO ECOLOGICO DELLA PRATERIA DI CYMODOCEA NODOSA VICINO AL PORTO DI CAPODISTRIA 
SINTESI 
Le praterie di fanerogame marine vengono considerate la controparte marina delle foreste pluviali tro­picali, e la loro salute č legata a diversi fattori di stress antropogenici, tra cui le rotte di navigazione e le attivitŕ portuali. Nel Mediterraneo, Cymodocea nodosa č considerata un indicatore efficace del cambiamento ambientale, a causa della sua distribuzione universale, della sensibilitŕ a varie pressioni naturali e antropoge-niche, e della misurabilitŕ delle risposte della specie agli impatti. Lo scopo di questo studio č di presentare i cambiamenti nella valutazione dello stato ecologico della prateria di C. nodosa vicino al porto di Capodistria, che č stato valutato come Cattivo nel 2018. I risultati mostrano un miglioramento significativo dello stato ecologico della prateria, che puň essere attribuito a una riduzione dei fattori di stress antropogenici. 
Parole chiave: Cymodocea nodosa, valutazione dello stato, indice MediSkew, Porto di Capodistria, Adriatico settentrionale 
185 
INTRODUCTION 
Seagrass meadows are among the most produc­tive environments in the seas and oceans world­wide (Spalding et al., 2003; Brodersen et al., 2018). They provide habitat niches, food, and protection from predators for many different organisms in lagoons and marine ecosystems (Hemminga & Du-arte, 2000; Como et al., 2008; Tuya et al., 2014; Espino et al., 2015). These environments are also important for human well-being (Nordlund et al., 2018; Unsworth et al., 2018), as they provide a range of ecosystem services, including moderat­ing wave action and thus protecting the coastline from erosion (Ondiviela et al., 2014; Cabaço & Rui Santos, 2014), stabilising sediments (Terrados & Borum 2004; Widdows et al., 2008), regulating nutrient cycling and sequestering carbon (Duarte et al., 2010; Luisetti et al., 2013), purification of seawater (Richir et al., 2013), and providing a sys­tem for education and research (Effrosynidis et al., 2018). For these reasons, they have been included as priority habitats in a number of legal regula­tions, including the European Habitats Directive (HD, 92/43/EEC). 
Seagrass beds are more or less the marine counterpart of tropical rainforests, and their health is associated with various types of anthropogenic stressors. These pressures include navigation routes and port activities, seabed dredging, com­mercial and recreational activities such as fishing and mooring, runoff from urban and agricultural areas, wastewater, and more recently, increasing climate change and ocean acidification (Short et al., 2011; Tuya et al., 2002; Marbŕ et al., 2014; Orlando-Bonaca et al., 2015, 2019; Repolho et al., 2017). Such pressures affect light and nutrient resources (Hemminga & Duarte, 2000), and cause physical damage to different sea bottom types (Montefalcone et al., 2008; Marbŕ et al., 2014). Rapid and widespread declines in seagrass mead­ows have been reported from many coastal areas over the past fifteen years (Orth et al., 2006; Tuya et al., 2013; Fabbri et al., 2015). Seagrasses have disappeared at a rate of 110 km2 per year since 1980, a value similar to the rates of loss described for mangroves, coral reefs, and tropical rainforests (Waycott et al., 2009). In terms of cover, one third of the world’s seagrass meadows are reported to have already disappeared (Waycott et al., 2009). 
Four native seagrass species are found in the Adriatic Sea: Posidonia oceanica (Linnaeus) Delile, Cymodocea nodosa (Ucria) Ascherson, Zostera ma­rina Linnaeus and Zostera noltei Hornemann (Lipej et al., 2006). In the Mediterranean Sea, C. nodosa is considered an effective indicator of environ­mental change, due to its universal distribution, sensitivity to various natural and anthropogenic pressures, and the measurability of the species’ responses to these impacts (Orfanidis et al., 2007, 2010; Oliva et al., 2012; Orlando-Bonaca et al., 2015; Papathanasiou et al., 2016). Although C. nodosa exhibits great phenotypic plasticity and can adapt to various natural and anthropogenic stressors through physiological and morphological adaptations, a sharp decline has been reported in coastal areas (Orth et al., 2006; Short et al., 2011; Tuya et al., 2013, 2014; Fabbri et al., 2015; Macic & Zordan, 2018; Najdek et al., 2020) in recent decades. 
In the northern Adriatic Sea, there is still a lack of long-time data series to support the con­servation status of C. nodosa meadows, which is included in Annex II (List of Endangered or Threatened species) of the Convention for the Protection of the Mediterranean Sea Against Pol­lution (the Barcelona Convention). The ecological status of C. nodosa meadows in the Gulf of Trieste was assessed using the MediSkew index (Orlando-Bonaca et al., 2015; 2016), which was developed in accordance with the requirements of the EU Water Framework Directive (WFD, 2000/60/EC) and the Marine Strategy Framework Directive (MSFD, 2008/56/EC). The ecological status of the 
C. nodosa meadow growing near the Port of Koper was first evaluated in 2018 (Orlando-Bonaca et al., 2019), and subsequently monitored in 2020 and 2021. An annual monitoring programme is planned for the future, as shipping routes and port activities are considered one of the main pressures on the 
Tab. 1: Boundaries among status classes for the MediSkew index (classes High and Good indicate a Good Environmental Status). Tab. 1: Meje med posameznimi razredi stanja za MediSkew indeks (razreda Zelo dobro in Dobro oznacujeta Dobro okoljsko stanje). 
Status classes  Absolute values of MediSKew  
High  0 = MediSKew < 0.2  
Good  0.2 = MediSKew < 0.4  
Moderate  0.4 = MediSKew < 0.6  
Poor  0.6 = MediSKew < 0.8  
Bad  0.8 = MediSKew = 1  

status of C. nodosa meadows (Orlando-Bonaca et al., 2015). The aim of this study is to present the changes in the assessment of the ecological status of the C. nodosa meadow near the port of Koper from 2018 using the MediSkew index. 
MATERIAL AND METHODS 

Study area, fieldwork and laboratory work 
The Port of Koper is a Slovenian multi-purpose port on the northern Adriatic Sea, mainly connect­ing markets in Central and South-eastern Europe with the Mediterranean Sea and the Far East. The marine part of the cargo port consists of tree basins, associated mooring piers and specialized loading terminals. The highest water turbidity values were measured during manoeuvres of the large ships (Žagar et al., 2014). Dredging of the sedimentary bottom was carried out in the Port of Koper along the access channels to Basin I (Luka Koper, 2015). Moreover, construction works, including dredging for the construction of a new RORO berth in the Basin III, were officially opened on May 27, 2019, and completed on March 31, 2020 (Franka Cepak, pers. comm.), resulting in a high sedimentation/ resuspension rate. 
The seagrass meadow located near the Port of Koper was sampled in July 2018, 2020 and 2021. Two sites (LuKp1 and LuKp2) were selected (Fig. 


Fig. 1: Map of sampling sites for Cymodocea nodosa near the Port of Koper (LuKp1 and LuKp2) and the reference site in the Moon Bay (Cy2). The site LuKp1 is located in the part of the C. nodosa meadow with a higher density, while the site LuKp2 is located in a less dense part of the meadow. Other colours on the map: the largest, light green circle = Zostera noltei; grey circles = boulders with Dictyota dichotoma, Padina pavonica and turf; red circle = boulders with Cystoseira compressa and P. pavonica; dark brown area = boulders with P. pavonica, Halopteris scoparia and turf; light brown area = boulders with Padina pavonica and turf. Sl. 1: Zemljevid mest vzorcenja kolencaste cimodoceje blizu Luke Koper (LuKp1 in LuKp2) in referencno mesto vzorcenja v Mesecevem zalivu (Cy2). LuKp1 se nahaja v zelo gostem delu travnika kolencaste ci­modoceje, medtem ko se LuKp2 nahaja v manj gostem delu. Druge barve na karti: najvecji, svetlozeleni krog = Zostera noltei; sivi krogi = skale prekrite z vrstama Dictyota dichotoma in Padina pavonica ter turfom; rdeci krog = skale prekrite z vrstama Cystoseira compressa in P. pavonica; temno rjavo obmocje = skale prekrite z vrstama P. pavonica in Halopteris scoparia ter turfom; svetlo rjavo obmocje = skale prekrite z vrsto Padina pavonica in turfom. 
Tab. 2: Statistic parameters (minimum, maximum, mean, median) and absolute value of skewness (|G|) of ln-transformed lengths of photosynthetically active parts of Cymodocea nodosa leaves from the sampling areas near the Port of Koper (LuKp1 and LuKp2) in 2018, 2020 and 2021, and in Moon Bay (Cy2, Strunjan Nature Reserve) in 2018. The reference median value in 2018 was 13.95 cm. Tab. 2: Statisticni parametri (minimum, maksimum, povprecje, mediana) in absolutna vrednost koe­ficienta asimetrije (|G|) ln-transformiranih dolžin fotosintetsko aktivnega dela listov kolencaste cimodoceje (C. nodosa) na tockah vzorcenja blizu Luke Koper (LuKp1 in LuKp2) v 2018, 2020 in 2021 ter v Mesecevem zalivu (Cy2, Naravni rezervat Strunjan) v 2018. Referencna mediana v 2018 je bila 13,95 cm. 
Area  Date  Min length (cm)  Max length (cm)  Mean (cm)  Median (cm)  |G|  
Str_3  12.7.2018  5.4  30.5  14.5  13.95  0.261  
Str_4  12.7.2018  8.1  22.7  13.5  13.20  0.022  
LuKp1_1  17.7.2018  5.9  66.2  37.8  41.25  1.423  
LuKp1_2  17.7.2018  6.0  57.1  34.7  37.05  1.162  
LuKp2_1  17.7.2018  3.7  58.8  30.7  30.45  1.533  
LuKp2_2  17.7.2018  6.9  52.2  27.3  28.25  1.130  
LuKp1_1  14.7.2020  5.4  62.5  32.0  31.90  1.044  
LuKp1_2  14.7.2020  7.4  57.7  29.9  29.25  0.706  
LuKp2_1  14.7.2020  5.1  61.3  29.2  28.90  0.979  
LuKp2_2  14.7.2020  7.3  55.9  31.4  31.25  0.955  
LuKp1_1  1.7.2021  8.7  55.8  27.33  25.90  0.355  
LuKp1_2  1.7.2021  7.3  57.1  28.12  27.20  0.442  
LuKp2_1  1.7.2021  11.5  47.7  24.72  22.95  0.142  
LuKp2_2  1.7.2021  5.7  46.2  24.15  23.15  0.659  

1) along the same isobath (3 m) and, within each site, two areas (LuKp1_1, LuKp1_2, and LuKp2_1, LuKp2_2) were chosen, approximately 100 m apart. In each area, five metallic frames (25 cm x 25 cm) were randomly placed on the bottom by SCUBA divers. These five squares were considered replicates of one sample. All shoots of C. nodosa located in each frame were carefully uprooted. The samples were labelled and individually placed in plastic bags. 
In July 2018, samples of C. nodosa were also collected in the Strunjan Nature Reserve (sampling site Cy2, areas Str_3 and Str_4). Due to the low Pressure Index for Seagrass Meadows (PISM) value, the area Str_3 was selected as the reference area for 
C. nodosa in the Gulf of Trieste in 2009 (Orlando-Bonaca et al., 2015), and it has to be sampled and assessed every 5 years. 
The samples of C. nodosa were stored in a freezer at -20°C in the laboratory of the Marine 

Tab. 3: MediSkew index values for the sampling areas of Cymodocea nodosa in the Port of Koper and in the Moon Bay (Strunjan) and assessment of the Ecological Status (according to the WFD) and Environ­mental Status (according to the MSFD). Tab. 3: Vrednosti indeksa MediSkew na tockah vzorcenja s kolencasto cimodocejo in opredelitev ekološkega stanja (glede na OVS) in okoljskega stanja (glede na ODMS) za morski travnik ob Luki Koper in v Mesecevem zalivu (Strunjan). 
Year  Area  Area’s MediSkew  Site’s MediSkew  Meadow’s MediSkew  Ecolog. Status  Environ. Status  N of leaves  N of adult leaves  
2018  Str_3  0.065  0.04  High  Good / Achieved  300  213  
Str_4  0.024  300  218  
LuKp1_1  1.00  0.935  0.825  Bad  Not good / Not achieved  300  225  
LuKp1_2  0.87  300  204  
LuKp2_1  0.79  0.715  300  247  
LuKp2_2  0.64  300  218  
2020  LuKp1_1  0.71  0.635  0.640  Poor  Not good / Not achieved  251  181  
LuKp1_2  0.56  300  223  
LuKp2_1  0.62  0.645  300  246  
LuKp2_2  0.67  300  222  
2021  LuKp1_1  0.39  0.415  0.37  Good  Good / Achieved  300  238  
LuKp1_2  0.44  300  207  
LuKp2_1  0.26  0.325  300  231  
LuKp2_2  0.39  300  212  

Biology Station Piran. The day before the analysis, they were slowly defrosted in a refrigerator. Sea-grass shoots were then kept in plastic wash basins containing seawater. Twenty shoots from each quadrat were randomly selected (Orfanidis et al., 2007). For each leaf (usually 5-6 leaves per shoot), the following parameters were measured to the nearest mm: length of the leaf sheath, length of the photosynthetic part and its width. The age of the leaf was designated as adult (when the leaf sheath was well-developed), intermediate (when the leaf sheath was weakly developed at the leaf base), and juvenile (when the leaf sheath was absent). The above measurements were made on at least 60 undamaged, photosynthetically active leaves (adult and/or intermediate) from each frame. One sample consisted of five replicates of 60 leaves (300 leaves in total). 
Additionally, in May 2020, the meadow and other vegetation types in the area were checked by applying a field method based on visual observa­tion of sea-bottom segments covered with vegeta­tion in the infralittoral belt. The survey consisted of a cruise along the coastline in a small boat. Sublittoral communities were identified using a large Aquascope Underwater Viewer and directly annotated in a graphic display. This graphic sup­port was prepared at an appropriate small scale and was suitable for use in the field. The final result is a division of the shoreline into several sectors, each identified by a community category (see Fig. 1). The information obtained on the distribution of communities was transcribed into a georeferenced graphic support in a Geographical Information System. All vegetation types between 1 and 4 m depth, were mapped. 


Data analysis 
To quantify changes in the photosynthetic part of the leaf length distribution for each C. nodosa sampling area near the Port of Koper, the MediSkew index was calculated (for details, see Orlando-Bonaca et al., 2015). The boundaries among the status classes for the MediSkew index were set equidistantly (Tab. 1). Five status classes are sufficient for the assessment of the Ecological Status (ES) according to the WFD. In addition, High and Good classes indicate Good Environ­mental Status (EnS) according to the MSFD, while the classes Moderate, Poor, and Bad are consid­ered Not Good EnS. 

RESULTS AND DISCUSSION 
The surveyed C. nodosa meadow near the Port of Koper can be considered as a part of the biocoeno-sis of superficial muddy sands in sheltered waters. The part of the meadow closest to the Port of Koper has a higher density of shoots than the part to the north (different green colours in Fig. 1). Within the meadow, rocky biotopes were also found, which include small communities dominated by Padina pavonica (Linnaeus) Thivy, Dictyota dichotoma (Hudson) J.V. Lamouroux, Halopteris scoparia (Linnaeus) Sauvageau and Cystoseira compressa (Esper) Gerloff & Nizamuddin. A monospecific patch of Zostera noltei was also found close to the Port (see Fig. 1). 
The parameters of C. nodosa per sampling area are shown in Table 2. The leaves of C. nodosa were significantly shorter in the areas within the reference site in the Moon Bay (Cy2) than in the areas near the Port of Koper in all years, and consequently so were the median val­ues (Tab. 2). The skewness |G| was the highest in the LuKp2_1 area in 2018 (Tab. 2). However, the results show that mean and median leaf length values decreased in all sampled areas in the Port of Koper in 2020 and additionally in 2021. Leaf lengths were still much longer than those at the reference area, but there is a very clear trend of decreasing leaf lengths since 2018 near the Port of Koper (Tab. 2). 
It should be emphasized that in 2020, many adult leaves of C. nodosa at LuKp1_1 were broken, without apical parts, and therefore we could not measure 300 undamaged leaves for this area (Tab. 3), as indicated in the methodology. All samples collected in 2021 had fewer damaged leaves and the number of adult leaves of C. nodosa exceeded 200 per sample (Tab. 3). 
The ES (according to WFD) and the EnS (ac­cording to MSFD) of sampling areas and sites were assessed according to the boundaries in Table 1. The MediSkew index values for each sampled area in the Port of Koper are presented in Table 3. The two areas of the sampling site LuKp2, furthest from the Port Basin III, improved the ES from Poor in 2018 and 2020 to Good in 2021. 
The improvement in the status of the LuKp1 sampling site is also impressive (Tab. 3). The area LuKp1_2 was assessed as Bad ES in 2018, while it remained Moderate in 2020 and 2021. The area LuKp1_1 improved from Bad ES in 2018 to Poor in 2020 and to Good in 2021. The ES of the entire meadow of C. nodosa near the Port of Koper was evaluated as Good in 2021, which is two orders of magnitude better than in 2020 (Tab. 3). 
The results obtained from 2018 to 2021 show a significant improvement in the ES of the C. nodosa meadow. The Good ES achieved in 2021 may be related to the reduction of anthropo­genic pressures, as the construction of the new RORO berth was completed in March 2020. This construction resulted in higher sediment resus­pension in recent years, leading to increased turbidity and consequently less light. Seagrasses are generally light-limited (Touchette & Burk-holder, 2000). Thus, when exposed to low light levels due to high water turbidity, they respond by increasing biomass distribution to the leaves. The increase in leaf size allows marine plants to capture more light and convert it into photosyn­thetic production (Greve & Binzer, 2004). That resuspension of sediments and water turbidity are critical to the health of C. nodosa meadows is confirmed by recent research (Orfanidis et al., 2020). Additionally, the decrease in anthro­pogenic pressures near the port area in 2020 was also influenced by the Covid-19 pandemic, which led to a decrease in maritime traffic, es­pecially cruise ship traffic in the Port of Koper, as reported in many local media. March et al. (2021) have attempted to assess the impact of the pandemic on maritime traffic globally, which in turn has implications for the blue economy and ocean health. 
The results of the present study are very en­couraging, and as the Port of Koper has prepared a long-term monitoring programme in the harbour area and its surroundings, we hope to confirm the improved ES of the C. nodosa meadow near the Port in the long term. 
ACKNOWLEDGEMENTS 
The authors are grateful to the Port of Koper that financially supported this study. We would like to thank also Lovrenc Lipej, Milijan Šiško, Tihomir Makovec, Borut Mavric, Domen Trkov, Aljoša Gracner, Matej Marinac and Tristan Bartole for their help during the fieldwork and laboratory work. Special thanks are due to Milijan Šiško for the preparation of Figure 1. We thank also the review­ers for their careful reading of the manuscript and their constructive remarks. 



IZBOLJŠANJE EKOLOŠKEGA STANJA MORSKEGA TRAVNIKA KOLENCASTE CIMODOCEJE (CYMODOCEA NODOSA) V BLIŽINI KOPRSKEGA PRISTANIŠCA 
Martina ORLANDO-BONACA 
Morska biološka postaja Piran, Nacionalni inštitut za biologijo, SI-6330 Piran, Fornace 41, Slovenia e-mail: martina.orlando@nib.si 
Erik LIPEJ 
Ulica XXX divizije 10, SI-6320 Portorož, Slovenia 
Romina BONACA 
Ulica Vena Pilona 5, SI-6000 Koper, Slovenia 
Leon Lojze ZAMUDA 
Morska biološka postaja Piran, Nacionalni inštitut za biologijo, SI-6330 Piran, Fornace 41, Slovenia 
POVZETEK 
Morski travniki so bolj ali manj morski ekvivalent tropskega deževnega gozda, njihovo zdravje pa je povezano z razlicnimi antropogenimi dejavniki, vkljucno s plovnimi potmi in pristaniškimi dejavnostmi. V Sredozemskem morju je kolencasta cimodoceja (Cymodocea nodosa) zaradi svoje univerzalne razšir­jenosti, obcutljivosti na razlicne naravne in antropogene pritiske ter merljivosti odzivov vrste na vplive, ucinkovit kazalnik okoljskih sprememb. Namen študije je predstaviti spremembe v oceni ekološkega stanja morskega travnika kolencaste cimodoceje v bližini koprskega pristanišca, ki je bilo 2018 oprede­ljeno kot Zelo slabo. Rezultati kažejo bistveno izboljšanje ekološkega stanja travnika, kar lahko pripišemo zmanjšanju antropogenih pritiskov. 
Kljucne besede: Cymodocea nodosa, ocena stanja, MediSkew indeks, Luka Koper, severni Jadran REFERENCES 
Brodersen, M.M., M. Pantazi, A. Kokkali, P. Panayotidis, V. Gerakaris, I. Maina, S. Kavadas, 
H. Kaberi & V. Vassilopoulou (2018): Cumulative Impacts from Multiple Human Activities on Seagrass Meadows in Eastern Mediterranean Waters: The Case of Saronikos Gulf (Aegean Sea, Greece). Environ. Sci. Pollut. Res., 25, 26809-26822. doi:10.1007/ s11356-017-0848-7. 
Cabaço, S. & A. Rui Santos (2014): Human-induced changes of the seagrass Cymodocea nodosa in Ria For­mosa lagoon (Southern Portugal) after a decade. Cah. Biol. Mar., 55, 101-108. 
Como, S., P. Magni, M. Baroli, D. Casu, G. De Falco & A. Floris (2008): Comparative analysis of macro-faunal species richness and composition in Posidonia oceanica, Cymodocea nodosa and leaf litter beds. Mar. Biol., 153(6), 1087-1101. 
Duarte, C.M., N. Marbŕ, E. Gacia, J.W. Fourqurean, 
J. Beggins, C. Barrón & E.T. Apostolaki (2010): Seagrass community metabolism: Assessing the carbon sink ca­pacity of seagrass meadows. Global Biogeochem. Cy., 24, GB4032. 
Effrosynidis, D., A. Arampatzis & G. Sylaios (2018): Seagrass detection in the Mediterranean: A supervised learning approach. Ecol. Inform., 48, 158-170. 
Espino, F., A. Brito, R. Haroun & F. Tuya (2015): Macroecological analysis of the fish fauna inhabiting Cymodocea nodosa seagrass meadows. J. Fish Biol., 87(4), 1000-1018. 
Fabbri F., F. Espino, R. Herrera, L. Moro, R. Haroun, 
R. Riera, N. González-Henriquez, O. Bergasa, O. Monterroso, M. Ruiz de la Rosa & F. Tuya (2015): Trends of the seagrass Cymodocea nodosa (Magnoliophyta) in the Canary Islands: population changes in the last two decades. Scientia Marina, 79(1), 7-13. 
Greve, T.M. & T. Binzer (2004): Which factors regulate seagrass growth and distribution? In: J. Borum, 
C.M. Duarte, D. Krause-Jensen, & T.M. Greve (Eds). European seagrasses: an introduction to monitoring and management. The M&MS project: 19-23. 
Habitat Directive (1992): Council Directive 92/43/ EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. 
Hemminga, M.A. & C.M.D. Duarte (2000): Seagrass ecology. Cambridge University Press, 298 pp. 
Lipej, L., R. Turk & T. Makovec (2006): Ogrožene vrste in habitatni tipi v slovenskem morju (Endangered species and habitat types in the Slovenian sea). Zavod RS za varstvo narave, Ljubljana, 264 pp. 
Luisetti, T., E.L. Jackson & R.K. Turner (2013): Valu­ing the European ‘coastal blue carbon’ storage benefit. Mar. Pollut. Bull., 71, 101-106. 
Luka Koper (2015): More about port’s history. Available at: https://luka-kp.si/eng/more-about-port-s-history. 
Macic, V. & C. Zordan (2018): Mapping of the Cy-modocea nodosa (Ucria) Asch. meadows in the Kotor Bay and data comparison over the last four decades. Studia Marina, 31(1), 5-15. 
Marbŕ, N., E. Diaz-Almela & C.M. Duarte (2014): Mediterranean seagrass (Posidonia oceanica) loss be­tween 1842 and 2009. Biol. Conserv., 176, 183-190. 
March, D., K. Metcalfe, J. Tintoré & B.J. Godley (2021): Tracking the global reduction of marine traffic during the COVID-19 pandemic. Nature Communica­tions, 12, 2415. https://doi.org/10.1038/s41467-021­22423-6. 
Marine Strategy Framework Directive (2008): Di­rective 2008/56/EC of the European Parliament and of the Council of 17 June 2008 establishing a framework for community action in the field of marine environ­mental policy. 
Montefalcone, M., M. Chiantore, A. Lanzone, C. Morri & G. Albertelli (2008): BACI design reveals the decline of the seagrass Posidonia oceanica induced by anchoring. Mar. Pollut. Bull., 56(9), 1637-1645. 
Najdek, M., M. Korlevic, P. Paliaga, M. Markovski, 
I. Ivancic, L. Iveša, I. Felja & G.J. Herndl (2020): Dy­namics of environmental conditions during the decline of a Cymodocea nodosa meadow. Biogeosciences, 17, 3299-3315. https://doi.org/10.5194/bg-17-3299-2020. 
Nikolic, V., A. Žuljevic, L. Mangialajo, B. Antolic, 
G. Kušpilic & E. Ballesteros (2013): Cartography of Littoral Rocky-Shore Communities (CARLIT) as a Tool for Ecological Quality Assessment of Coastal Waters in the Eastern Adriatic Sea. Ecol. Indic., 34, 87-93. doi:10.1016/j.ecolind.2013.04.021. 
Nordlund, L.M., R.K.F. Unsworth, M. Gullstrom & 
L.C. Cullen-Unsworth (2018): Global significance of seagrass fishery activity. Fish and Fisheries, 19(3), 399­412. https://doi.org/10.1111/faf.12259. 
Oliva, S., O. Mascaró, I. Llagostera, M. Pérez, & 
J. Romero (2012): Selection of Metrics Based on the Seagrass Cymodocea nodosa and Development of a Biotic Index (Cymox) for Assessing Ecological Status of Coastal and Transitional Waters. Estuar. Coast. Shelf S., 114, 7-17. 
Ondiviela, B., I.J. Losada, J.L. Lara, M. Maza, C. Galván, T.J. Bouma & J. van Belzen (2014): The role of seagrasses in coastal protection in a changing climate. Coast. Engineering, 87, 158-168. 
Orfanidis, S., V. Papathanasiou & S. Gounaris (2007): Body size descriptor of Cymodocea nodosa indicates anthropogenic stress in coastal ecosystem. Transitional Waters Bulletin, 2, 1-7. 
Orfanidis, S., V. Papathanasiou, S. Gounaris, & T. Theodosiou (2010): Size distribution approaches for monitoring and conservation of coastal Cymodocea habitats. Aquatic Conservation: Marine and Freshwater Ecosystems, 20, 177–188. 

Orfanidis, S., V. Papathanasiou, N. Mittas, T. Theo-dosiou, A. Ramfos, S. Tsioli, M. Kosmidou, A. Kafas, 
A. Mystikou & A. Papadimitriou (2020): Further im­provement, validation, and application of CymoSkew biotic index for the ecological status assessment of the Greek coastal and transitional waters. Ecol. Indic., 118, 106727. 
Orlando-Bonaca, M., J. Francé, B. Mavric, M. Grego, L. Lipej, V. Flander Putrle, M. Šiško & A. Falace (2015): A new index (MediSkew) for the assessment of the Cymodocea nodosa (Ucria) Ascherson meadows’s status. Marine Environmental Research, 110, 132-141. 
Orlando-Bonaca, M., L. Lipej & J. Francé (2016): The most suitable time and depth to sample Cymodo­cea nodosa (Ucria) Ascherson meadows in the shallow coastal area. Experiences from the northern Adriatic Sea. Acta Adriatica, 57(2), 251-262. 
Orlando-Bonaca, M., J. Francé, B. Mavric & L. Lipej (2019): Impact of the Port of Koper on Cymodocea nodosa meadow. Annales, Series Historia Naturalis, 29(2), 187-194. 
Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L. Heck, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M. Waycott & S.L. Williams (2006): A global crisis for seagrass ecosystems. BioSci., 56, 987-996. 
Papathanasiou, V., S. Orfanidis & M.T. Brown (2016): Cymodocea nodosa metrics as bioindicators of anthropogenic stress in N. Aegean, Greek coastal waters. Ecol. Indic., 63, 61-70. 
Repolho, T., B. Duarte, G. Dionísio, J.R. Paula, A.R. Lopes, I.C. Rosa, T.F. Grilo, I. Caçador, R. Calado & 
R. Rosa (2017): Seagrass ecophysiological performance under ocean warming and acidification. Sci. Rep., 7, 41443. doi: 10.1038/srep41443. 
Richir, J., N. Luy, G. Lepoint, E. Rozet, A. Alvera Azcarate & S. Gobert (2013): Experimental in situ ex­posure of the seagrass Posidonia australis (L.) Delile to 15 trace elements. Aquat. Toxicol., 140-141, 157-173. 
Short, F.T., B. Polidoro, S.R. Livingstone, K.E. Carpenter, S. Bandeira, J.S. Bujang, H.P. Calumpong, 
T.J.B. Carruthers, R.G. Coles, W.C. Dennison, P.L.A. Er-ftemeijer, M.D. Fortes, A.S. Freeman, T.G. Jagtap, A.M. Kamal, G.A. Kendrick, W.J. Kenworthy, Y.A. La Nafie, 
I.M. Nasution, R.J. Orth, A. Prathep, J.C. Sanciangco, 
B. van Tussenbroek & S.G. Vergara (2011): Extinction risk assessment of the world’s seagrass species. Biol. Conserv., 144, 1961-1971. 
Spalding, M., M. Taylor, C. Ravilious, F.T. Short & E. Green (2003): The distribution and status of seagrasses. In: Green, E.P. et al. (Eds.). World atlas of seagrasses. pp. 5-26. 
Terrados, J. & J. Borum (2004): Why are seagrasses important? - Goods and services provided by seagrass meadows. In: Borum, J., C.M. Duarte, D. Krause-Jensen, & T.M. Greve (Eds). European seagrasses: an introduc­tion to monitoring and management. The M&MS pro­ject, pp. 8-10. 
Touchette B.W. & J.M. Burkholder (2000): Overview of the physiological ecology of carbon metabolism in seagrasses. Journal of Experimental Marine Biology and Ecology, 250, 169-205. 
Tuya, F., J.A. Martín & A. Luque (2002): Impact of a marina construction on seagrass bed at Lanzarote (Canary Islands), J. Coast. Conserv., 8, 157-162. 
Tuya, F., H. Hernandez-Zerpa, F. Espino & R. Haroun (2013): Drastic decadal decline of the seagrass Cymodocea nodosa at Gran Canaria (eastern Atlantic): Interactions with the green algae Caulerpa prolifera. Aquat. Bot., 105, 1-6. 
Tuya, F., L. Ribeiro-Leite, N. Arto-Cuesta, J. Coca, 
R. Haroun & F. Espino (2014): Decadal changes in the structure of Cymodocea nodosa seagrass meadows: Natural vs. human influences. Estuar. Coast. Shelf S., 137, 41-49. 
Unsworth, R.K.F., L.M. Nordlund & L.C. Cullen-Un­sworth (2018): Seagrass meadows support global fish­eries production. Conservation Letters, 12(1), e12566. https://doi.org/10.1111/conl.12566. 
Water Framework Directive (2000): Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. 
Waycott, M., C.M. Duarte, T.J. Carruthers, R.J. Orth, W.C. Dennison, S. Olyarnik, A. Calladine, J.W. Fourqurean, KL. Heck JR., A.R. Hughes, G.A. Kendrick, 
W.J. Kenworthy, F.T. Short & S.L. Williams (2009): Ac­celerating loss of seagrasses across the globe threatens coastal ecosystems. P. Natl. Acad. Sci. USA, 106, 12377-12381. 
Widdows, J., N.D. Pope, M.D. Brinsley, H. Asmus & R.M. Asmus (2008): Effects of seagrass beds (Zostera noltii and Z. marina) on near-bed hydrodynamics and sediment resuspension. Mar. Ecol. Prog. Ser., 358, 125­136. 
Žagar, D., V. Ramšak, M. Jeromel, M. Perkovic, 
M. Licer & V. Malacic (2014): Modelling sediment re­suspension caused by navigation, waves and currents (Gulf of Trieste, northern Adriatic). In: de Almeida, 
A.B. et al. (Eds.). 3rd IAHR Europe Congress: Water engineering and research. Book of abstracts. Faculty of Engineering of the University of Porto (FEUP), Por­tugal, pp. 86-87.