First records of leatherback turtle (Dermochelys coriacea) in the Black Sea, Türkiye
05/26/2026First records of leatherback turtle (Dermochelys coriacea) in the Black Sea, Türkiye
Oguz Turkozan, Ayaka Amaha Öztürk, Ayhan Dede, Ulgen Aytan, Aylin Güler
ORCID IDs: O.T. 0000-0001-6889; A.A.Ö. 0000-0003-2281-7372; A.D. 0000-0002-7712-615X; U.A. 0000-0002-6530-3083; A.G. 0009-0008-4117-7511
Turkish Marine Research Foundation (TUDAV), Beykoz, Istanbul, TÜRKİYE
Department of Biology, Faculty of Science, Aydın Adnan Menderes University, 09010 Aydın, TÜRKİYE
Microplastic Research Unit, Faculty of Fisheries, Recep Tayyip Erdogan University, 53100 Rize, TÜRKİYE
Faculty of Aquatic Sciences, Istanbul University, 34134 Istanbul, TÜRKİYE
Institute of Graduate Studies in Sciences, İstanbul University, 34116, Fatih, İstanbul, TÜRKİYE
Abstract
This study presents the first confirmed records of the leatherback sea turtle (Dermochelys coriacea) from the Black Sea coast of Türkiye, documenting both a stranded dead individual and a live occurrence. A dead female recorded from Karasu Beach, Sakarya, located at the western Black Sea coast of Türkiye, on 13 April 2025 was subjected to a detailed necropsy, including external and internal examinations, morphometric measurements, and biological sampling. A second record involved a live individual observed off the coast of Rize Province on 7 April 2026. Leatherback turtles are considered rare and irregular visitors in Turkish waters and are typically recorded in the Mediterranean and, less frequently, in the Aegean Sea. These records represent the first confirmed occurrences of the species from the Black Sea coast of Türkiye and the northernmost confirmed occurrence in Turkish seas, following a recent observation of a live individual in the Istanbul Strait, Marmara Sea, in July 2024. The findings contribute to the limited knowledge of leatherback turtle occurrence in marginal habitats and further highlight plastic pollution as an increasing threat in the Black Sea, with potential impacts even on rare and vagrant marine species. The study underlines the importance of continued monitoring, reporting, and conservation efforts for both threatened megafauna and the growing pressure of marine litter in the region.
Keywords: Sea turtle, distribution, endangered species, plastic pollution, Black Sea
Pages: 92-107
References
ACCOBAMS (2021) Estimates of Abundance and Distribution of Cetaceans, Marine Mega-fauna and Marine Litter in the Mediterranean Sea from 2018-2019 Surveys, (eds., Panigada, S., Boisseau, O., Canadas, A., Lambert, C., Laran, S., McLanaghan, R., Moscrop, A.). ACCOBAMS- ACCOBAMS Survey Initiative Project, Monaco.
Ak, O., Polat, H., Küçük, E., Selen, H. (2016) First confirmed record of the green sea turtle, Chelonia mydas (Linnaeus, 1758) (Cheloniidae), from the eastern Black Sea waters of Turkey. Turkish Journal of Zoology 40: 1-4.
Arslan, G., Ertürk, A., Candan, O. (2023) Predicting the distribution of green turtle nesting sites over the Mediterranean with outcoming climate driven changes. Journal for Nature Conservation 71: 126320.
Aytan, U., Esensoy, F.B., Senturk, Y. Arifoğlu, E., Karaoğlu, K., Ceylan, Y., Valente, A. (2022a) Plastic occurrence in commercial fish species of the Black Sea. Turkish Journal of Fisheries and Aquatic Sciences 22(SI): TRJFAS20504.
Aytan, U., Esensoy, F.B., Şentürk, Y. (2022b) Microplastic ingestion and egestion by copepods in the Black Sea. Science of the Total Environment. doi: 10.1016/J.Scitotenv.2021.150921.
Aytan, Ü., Koca, Y.Ş., Pasli, S., Güven, O., Ceylan, Y., Basaran, B. (2025) Microplastics in commercial fish and their habitats in the important fishing ground of the Black Sea: Characteristic, concentration, and risk assessment. Marine Pollution Bulletin 221: 118434.
Aytan, U., Pogojeva, M., Simeonova, A. (eds.) (2020) Marine Litter in the Black Sea. Turkish Marine Research Foundation (TUDAV), Publication No: 56, Istanbul, Turkey.
Baran, İ., Durmuş, S.H., Türkozan, O. (1998) Erster nachweis der Lederschildkröte, Dermochelys coriacea (Linnaeus, 1766) (Testudines: Dermochelyidae) aus Türkischen Gewassern. Herpetofauna 20(112): 34.
Baran, İ., Kasparek, M. (1989) Marine Turtles – Turkey. Status Survey 1998 and Recommendations for Conservation and Management. WWF, Heidelberg.
Bat, L., Satılmış, H.H., Birinci-Özdemir, Z., Şahin, F., Üstün, F. (2009) Distribution and population dynamics of Aurelia aurita (Cnidaria; Scyphozoa) in the southern Black Sea. North-Western Journal of Zoology 5(2): 225-241.
Boero, F. (2013) Review of Jellyfish Blooms in the Mediterranean and Black Sea. General Fisheries Commission for the Mediterranean. Studies and Reviews, FAO, Rome.
Camiñas, J.A. (1998) Is the leatherback (Dermochelys coriacea Vandelli, 1761) a permanent species in the Mediterranean Sea? Rapports de la Commission Internationale de la Mer Méditerranée 38: 388-389.
Canbolat, A.F. (2004) A review of sea turtle nesting activity along the Mediterranean coast of Turkey. Biological Conservation 116(1): 81-91.
Candan, O., Canbolat, A.F. (2018) New record of a leatherback (Dermochelys coriacea) stranding in Turkey. Biharean Biologist 12(1): 56-57.
Caracappa, S., Persichetti, M.F., Gentile, A., Caracappa, G. (2017) New records of leatherback sea turtle, Dermochelys coriacea (Vandelli, 1761) (Testudines: Dermochelyidae) in the Strait of Sicily. Cahiers de Biologie Marine 58(3): 353-357.
Casale, P., Nicolosi, P., Freggi, D., Turchetto, M., Argano, R. (2003) Leatherback turtles (Dermochelys coriacea) in Italy and in the Mediterranean basin. Herpetological Journal 13(3): 135-140.
Doyle, T.K., Houghton, J.D., O’Súilleabháin, P.F., Hobson, V.J., Marnell, F., Davenport, J., Hays, G.C. (2008) Leatherback turtles satellite-tagged in European waters. Endangered Species Research 4(1-2): 23-31.
Eckert, S.A. (2006) High-use oceanic areas for Atlantic leatherback sea turtles (Dermochelys coriacea) as identified using satellite telemetered location and dive information. Marine Biology 149(5): 1257-1267.
Ergene, S., Uçar, A.H. (2017) A leatherback sea turtle entangled in fishing net in Mersin Bay, Mediterranean Sea, Turkey. Marine Turtle Newsletter 153: 5-6.
Ferraroli, S., Georges, J.Y., Gaspar, P., Le Maho, Y. (2004) Endangered species – where leatherback turtles meet fisheries. Nature 429: 521-522.
Fujitani, T., Ena, S., Hosoya, T., Lee, S., Nishijima, M., Iguchi, A., Nakano, H., Iwasaki, N. (2026) Multiple approaches to meso- and macroplastics and the food habitat of the green turtle, Chelonia mydas, in the Ogasawara Islands, Japan. PeerJ 14:e20425.
Garofalo, L., Lorenzini, R., Marchiori, E., Poppi, L., Giglio, S., Mizzan, L., Novarini, N. (2020) Oceanic giants in the Mediterranean: first mitochondrial analysis of leatherback turtles (Dermochelys coriacea) in the Adriatic and Tyrrhenian seas. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 29(suppl. 1): 31-36.
Hays, G.C., Houghton, J., Myers, A. (2004) Endangered species: Pan-Atlantic leatherback turtle movements. Nature 429(6991): 522.
Hughes, G.R., Luschi, P., Mencacci, R., Papi, F. (1998) The 7000-km oceanic journey of a leatherback turtle tracked by satellite. Journal of Experimental Marine Biology and Ecology 229(2): 209-217.
James M.C., Davenport, J., Hays, G.C. (2006) Expanded thermal niche for a diving vertebrate: A leatherback turtle diving into near-freezing water. Journal Experimental Marine Biology and Ecology 335: 221-226.
Jones T.T., Hastings, M.D., Bostrom, B.L., Pauly, D., Jones, D.R. (2011) Growth of captive leatherback turtles, Dermochelys coriacea, with inferences on growth in the wild: Implications for population decline and recovery. Journal of Experimental Marine Biology and Ecology 399: 84-92.
Jony, M., Salhab, S., Rees, A.F. (2025) The first leatherback sea turtle observed during a nesting attempt in the Mediterranean. Chelonian Conservation and Biology 24(2): 279-281.
Lambardi, P., Lutjeharms, J.R.E., Mencacci, R., Hays, G.C., Luschi, P. (2008) Influence of ocean currents on long-distance movement of leatherback sea turtles in the Southwest Indian Ocean. Marine Ecology Progress Series 353: 289-301.
Mancino, C., Canestrelli, D., Maiorano, L. (2022) Going west: Range expansion for loggerhead sea turtles in the Mediterranean Sea under climate change. Global Ecology and Conservation 38: e02264.
McDonald, D.L., Dutton, P.H. (1996) Use of PIT tags and photo identification to revise remigration estimates of leather back turtles (Dermochelys coriacea) nesting in St. Croix, U.S. Virgin Islands, 1979–1995. Chelonian Conservation and Biology 2(2): 148-152.
Millot, C., Taupier-Letage, I. (2005) Circulation in the Mediterranean Sea. The Mediterranean Sea in Handbook of Environmental Chemistry. Springer, Berlin.
Mrosovsky, N., Ryan, G.D., James, M.C. (2009) Leatherback turtles: the menace of plastic. Marine Pollution Bulletin 58(2): 287-289.
Mutlu, E. (2001) Distribution and abundance of moon jellyfish (Aurelia aurita) and its zooplankton food in the Black Sea. Marine Biology 138: 329-339.
Nankinov, D.M. (1998) Occurrence of marine turtles (Caretta caretta and Chelonia mydas) along the west Black Sea coast. Bulletin of the Natural History Museum, Belgrade, B49-50(1995-1998): 7-14.
Oğuz, T., Öztürk, B. (2011) Mechanisms impeding natural Mediterranization process of Black Sea fauna. Journal of the Black Sea/Mediterranean Environment 17(3): 234-253.
Oruç, A. (2001) Trawl fisheries in the eastern Mediterranean and their impact on marine turtles. Zoology in the Middle East 24(1): 119-125.
Oruç, A., Demirayak, F., Şat, G. (1997). The Impact of Trawl Fishing on Sea Turtles in the Eastern Mediterranean Project, pp. 16-17. (in Turkish)
Özdilek, Ş.Y., Sönmez, B., Sert, M. (2018) Stranded sea turtle records between 2010 and 2017 in northern Aegean and Sea of Marmara. Regional Studies in Marine Science 24: 17-22.
Öztürk, B., Tonay, A.M., Akkaya, A., Öztürk, A.A., Dede, A. (2011) Stranding of a green turtle, Chelonia mydas (Linnaeus, 1758), in the Turkish Black Sea. Zoology in the Middle East 52: 115-117.
Pestov, M.V., Kletnoy, M.V. (2012) Finding of the sea turtle Caretta caretta at the Russian coast of the Black Sea. Sovremennaya Herpetologia 12(3-4): 158-159.
Piboon, P., Brown, J., Kaewmong, P., Kittiwattanawong, K., Nganvongpanit, K. (2025), Biology, nesting behavior, genetic diversity, and conservation of leatherback sea turtles: Insights from Thailand and global perspectives. Ecology and Evolution 15: e71014.
Poppi, L., Marchiori, E. (2013) Standard Protocol for Post-mortem Examination on Sea Turtles. Network for the Conservation of Cetaceans and Sea Turtles in the Adriatic (NETCET), Blue World Institute.
Roden, S.E., Stewart, K.R., James, M.C., Dodge, K.L., Dell’Amico, F., Dutton, P.H. (2017) Genetic fingerprinting reveals natal origins of male leatherback turtles encountered in the Atlantic Ocean and Mediterranean Sea. Marine Biology 164(9): 181.
Sentürk, Y., Aytan, U. (2024) Microplastic ingestion by planctonic larvae of gastropods and bivalves in the Black Sea. Turkish Journal of Fisheries & Aquatic Sciences 24(SI): TRJFAS26829.
Sönmez, B., Sammy, D., Yalçın-Özdilek, Ş., Gönenler, Ö.A., Açıkbaş, U., Ergün, Y., Kaska, Y. (2008) A stranded leatherback sea turtle in the Northeastern Mediterranean, Hatay, Turkey. Marine Turtle Newsletter 119: 12-13.
Taşkavak, E., Akçınar, S.C., İnanlı, Ç. (2015) Rare occurrence of the leatherback sea turtle, Dermochelys coriacea, in İzmir Bay, Aegean Sea, Turkey. Ege Journal of Fisheries and Aquatic Sciences 32(1): 51-52.
Taşkavak, E., Farkas, B. (1998) On the occurrence of the leatherback turtle, Dermochelys coriacea, in Turkey (Testudines: Dermochelyidae). Zoology in the Middle East 16: 71-75.
Tonay, A.M., Oruç, A. (2016) Sea turtle records in the Sea of Marmara. In: The Sea of Marmara Marine Biodiversity, Fisheries, Conservation and Governance (eds., Özsoy, E., Çağatay, M.N., Balkıs, Ne., Balkıs, Nu., Öztürk, B.) Turkish Marine Research Foundation, Publication no: 42, İstanbul, pp.843-848.
Türkozan, O., Kaska, Y. (2010) Turkey. In: Sea Turtles in the Mediterranean: Distribution, Threats and Conservation Priorities, (eds., Casale, P., Margaritoulis, D.), Gland, Switzerland, IUCN, pp. 257-294.
Türkozan, O., Tonay, A.M. (2024) First record of leatherback turtle Dermochelys coriacea in the İstanbul Strait, Türkiye. Journal of the Black Sea/Mediterranean Environment 30(2): 152-159.
Wallace, B.P., Posnik, Z.A., Hurley, B.J., DiMatteo, A.D., Bandimere, A., Rodriguez, I., Maxwell, S.M., Meyer, L., Brenner, H., Jensen, M.P., La Casella, E., Shamblin, B.M., Abreu-Grobois, F.A., Stewart, K.R., Dutton, P.H., Barrios-Garrido, H., Dalleau, M., Dell’Amico, F., Eckert, K.L., FitzSimmons, N.N., Garcia-Cruz, M., Hays, G.C., Kelez, S., Lagueux, C.J., Madden Hof, C.A., Marco, A., Martins, S.L.T., Mobaraki, A., Mortimer, J.A., Nel, R., Phillott, A.D., Pilcher, N.J., Putman, N.F., Rees, A.F., Rguez-Baron, J.M., Seminoff, J.A., Swaminathan, A., Türkozan, O., Vargas, S.M., Vernet, P.D., Vilaça, S., Whiting, S.D., Hutchinson, B.J., Casale, P., Mast, R.B. (2023) Marine turtle regional management units 2.0: an updated framework for conservation and research of wide-ranging megafauna species. Endangered Species Research 52: 209-223.
Zaitsev, Yu., Mamaev, V. (1997) Marine Biological Diversity in the Black Sea: A Study of Change and Decline. Black Sea Environment Series, Vol. 3 NY: United Nations Publications.
Zinenko, O., Vishnyakova, K.A., Stoyanov, L., Gol’din, P.E. (2021) The northernmost record of the loggerhead sea turtle, Caretta caretta (Testudines, Cheloniidae), in the Black Sea with the review of the species occurrence in the region. Zoodiversity 55(2): 127-132.
Zug, G.R., Parham, J.F. (1996) Age and growth in leatherback turtles, Dermochelys coriacea (Testudines: Dermochelyidae): a skeletochronological analysis. Chelonian Conservation and Biology 2: 244-249.