Karadeniz’de Yaşayan Yunus Türleri ve Balıkçılığa Etkileri

B aşta coğrafik izolasyon olmak üzere düşük tuzluluk, yüksek hipoksik miktarı ve derinliği 100-250 m’nin altındaki suların anoksik olması nedeniyle Karadeniz’deki biyolojik çeşitlilik düşüktür. Bu nedenle yalnızca mutur Phocoena phocoena , kısa gagalı yunus Delphinus delphis ve afalina Tursiops truncatus olmak üzere üç yunus türü yaşamaktadır. Sunulan bu çalışmada türlerin biyolojik özellikleri, ekolojik istekleri, yaşam alanları üzerinde durulmuş, gerek ekosisteme gerekse balıkçılığa etkileri üzerine değerlendirmeler yapılmıştır. Deniz memelileri gibi birçok türün özellikle antropojenik etmenler sonucunda olumsuz olarak etkilenmesinden dolayı Dünya Koruma Birliği IUCN tarafından “Kırmızı Liste” de Delphinus delphis türü en az tehlikede LC , Akdeniz alt popülasyonu ise soyu tehlike altında EN olarak, Phocoena phocoena türü en az tehlikede LC , Tursiops truncatus türü en az tehlikede LC , Tursiops truncatus türünün Akdeniz alt popülasyonu ise hassas VU şeklinde belirtilmiştir. 280-360 mm ağ göz açıklığına sahip kalkan ağlarıyla gerçekleştirilen balıkçılıkta, yunusların istenmeden avlanması ve büyük olasılıkla ölmesi ya da öldürülmesi bu etkilerin başında gelmektedir. Ayrıca, özellikle 32-44 mm ağ göz açıklığına sahip dip uzatma ağlarıyla yapılan avcılıkta, yunusların ağlara yakalanmış balıkları çalması ve bu sırada ağları parçalaması da balıkçılık üzerinde olumsuz bir etkiye yol açmaktadır

Anahtar Kelimeler:

Karadeniz, Balıkçılık, Yunus, Delphinus delphis, Tursiops truncatus, Phocoena phocoena

Dolphins Inhabiting in Black Sea and Effects of Fisheries

Dolphins are the most important members of the marine mammals which undergo a decrease in population for many reasons such as overfishing, habitat degradation, maritime / traffic and pollution. Biodiversity in the Black Sea is low mostly due to the geographical isolation and low salinity, high hypoxic amount and anoxic bottom waters of 100-250 m depth as well. Therefore, only the three dolphin species; the harbour porpoise Phocoena phocoena , common dolphin Delphinus delphis and bottlenose dolphin Tursiops truncatus live in the Black Sea region. This study is about harbor porpoise, short-beaked dolphin and bottlenose dolphin living in the Black Sea . The results of the scientific researches and publications focusing on these species are scanned and gathered together. The biological characteristics, ecological requirements and habitats of these species are reviewed, effect on both ecosystem and fisheries are evaluated. Many species of the marine mam- mals are negatively effected by anthropogenic factors and as a result given in the Red List” by the the World Conservation Union IUCN where; Delphinus delphis is stated as least compromised LC , he Mediterranean sub-population is stated as endangered EN , Phocoena phocoena is stated as least compromised LC , Tursiops truncatus is stated as least compromised LC and Mediterranean subpopulation of Tursiops truncatus is stated as sensitive VU . Unintentional catch of dolphins, mostly resulting in death or killing of these species, by turbot nets having 280-360 mm mesh size is one of the leading anthropogenic factors. Besides, dolphins’ stealing fish particularly from the bottom gillnets with 32-44 mm mesh size and destroying these nets have a negative impact on fishing. In many parts of the world, many studies were perfomed to prevent unintentional catch bycatch of the dolphins and to keep away the dolphins from the nets in order to prevent fish stealing depredation and damaging of the nets. Studies have also been carried on focusing on the unintentional catch bycatch of dolphins in the Black Sea region, however researches particularly on acoustic dolphin repellents are very limited.

Keywords:

Black Sea, Fisheries, Dolphin, Delphinus delphis, Tursiops truncatus, Phocoena phocoena,

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1. CPBSAP, Strategic Action Plan for the Environmental Protection and Rehabilitation of the Black Sea, The Commission on the Protection of the Black Sea Against Pollution, Bulgaria, 17 April (2009), 70 p.
2. A. Acara, Evaluation of Black Sea dolphins in the industry. Hidrobiyoloji Mecmuası. Istanbul University Hydrobiology Research Institute Publications, Vol 3, No 1 .1965. Istanbul.
3. A. Jr. Birkun, The state of cetacean populations. (ed. T. Oğuz), State of the Environment of the Black Sea (2001-2006/7). Publication of the Commission on the Protection of the Black Sea Against Pollution (BSC), Istanbul, Turkey, 2008, pp. 365-395.
4. A.M. Tonay, A. Amaha Öztürk, Historical records of cetacean fishery in the Turkish seas. J. Black Sea/ Mediterranean Environment, 18 (2012) 388-399.
5. H. Arpa, Short stories about fishmen and fisheries from Yakakent. Yakakent Municipality Culture Publications, Samsun, 2012, 328 p.
6. E.P. Slastenenko, Black Sea Dolphins. Hidrobiologi Mecmuası, Istanbul University Hydrobiology Research Institute Publications Serial A, 3 (1955) 68- 89.
7. M. Yel, E. Özdemar, A. Amaha, N. Miyazaki, Some aspects of dolphin fishery on the Turkish Coast of the Black Sea. In: (ed., B. Öztürk), Proceedings of the First International Symposium on the Marine Mammals of the Black Sea, İstanbul, 1996, pp. 31-40.
8. A. Birkun, Jr., The current status of bottlenose dolphins (Tursiops truncatus) in the Black Sea. The review is based on the document presented at the 1st Meeting of the Parties of the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (Monaco, 28 February–2 March 2002).
9. A. Dede, A.A. Ozturk, A.M. Tonay, Cetacean surveys in the Istanbul (Bosphorus) Strait in 2008. In: G.J. Pierce, E. Philips, R. Lick (Eds.), Proceedings CD of 22nd Annual Conf. European Cetacean Society, Egmond aan Zee, the Netherlands, 2008.
10. A.A. Ozturk, A. Dede, A.M. Tonay, B. Ozturk, Cetacean surveys in the Istanbul (Bosphorus) Strait in 2007- 2008. In: Abstracts of 23rd Annual Conf. European Cetacean Society, Istanbul, Turkey, 2009.
11. A.M. Tonay, A. Dede, A.A. Ozturk, B. Ozturk, Cetacean strandings in the Turkish Straits System (TSS) and the Northern Aegean Sea coast of Turkey during 1999-2008. In: Proc. 23rd Annual Conf. European Cetacean Society, Istanbul, Turkey, 2009.
12. A. Dede, Marine mammals of the Marmara Sea. In: B. Ozturk (Ed.), Proceedings of the Symposium ‘The Marmara Sea 2010’, Turkish Marine Research Foundation Publications no: 32, 2010, pp. 272-281.
13. IWC, Annex L. Report of the Sub-committee on Small Cetaceans. J. Cetacean Res. Manage. 6 (Suppl.) (2004) 315-334.
14. A. Jr. Birkun, S. Krivokhizhin, K. Kosova, Bottlenose dolphin (Tursiops truncatus) became prevalent cetacean species in Black Sea coastal waters off the Crimea. P. 409 In: P.G.H. Evans and E. O’Boyle (Eds.), European research on cetaceans - 15 (Proc. 15th Annual Conf. European Cetacean Society, Rome, Italy, 6-10 May 2001). ECS, Kiel, (2004b) 478 pp.
15. A. Jr. Birkun, S.V. Krivokhizhin, V.Y. Gridin, A.V. Zhbanov, A.V. Zanin, I.V. Masberg, Strandings of neonate Black Sea harbour porpoises (Phocoena phocoena) as a probable consequence of the nursing females’ death in fishing gear. In: Marine Mammals of the Holarctic: Collection of Scientific Papers after the 3rd Internat. Conf., pp. (2004a) 59-64, Koktebel, Ukraine, 11-17 October 2004, Moscow, 609 pp.
16. A. Jr. Birkun, Bottom-set gillnet fisheries and harbour porpoises in the Black Sea: High-tech against cetaceans. FINS (the Newsletter of ACCOBAMS), 2(1) (2005) 10 pp.
17. IUCN, The Status and Distribution of Cetacean in the Black Sea and Mediterranean Sea. Workshop report, Monaco 5-7 March, 2006.
18. V.A. Yaskin, V.L. Yukhov, The numbers and distribution of Black Sea bottlenose dolphins. In: V.E. Sokolov and E.V. Romanenko (Eds.), The Black Sea Bottlenose Dolphin Tursiops truncatus ponticus: Morphology, Physiology, Acoustics, Hydrodynamics, pp. 19-26, Nauka, Moscow. 1991. 672 pp.
19. D. W. Rice, Marine Mammals of the World: Systematics and Distribution. Special Publication Number 4. Society for Marine Mammalogy, Lawrence, KS, 1998.
20. A. Jr. Birkun, Cetaceans (Cetacea). In: Y.P. Zaitsev et al. (Eds.), The North-Western Black Sea: Biology and Ecology. Naukova Dumka, Kiev. 2006. 703 pp.
21. B. Öztürk, A.A. Öztürk, Preliminary study on dolphin occurrence in Turkish straits system. In: P.G.H. Evans, E.C.M. Parsons and S.L. Clark (Eds.), European research on cetaceans-11, (Proc. 11th Annual Conf. European Cetacean Society, Stralsund, Germany, 10- 12 March 1997), ECS, Kiel., 1997.
22. A. Jr. Birkun, Kuiken, T. Krivokhizhin, S. Haines, A.D.D.M Osterhaus, M.W. van de Bildt, C.R. Joiris, and U. Siebert, Epizootic of morbilliviral disease in common dolphins (Delphinus delphis ponticus) from the Black Sea. Veterinary Records 144(4) (1999) 85- 92.
23. A. Birkun, Jr., Cetacean habitat loss and degradation in the Black Sea. In: G. Notarbartolo di Sciara (Ed.), Cetaceans of the Mediterranean and Black Seas: state of knowledge and conservation strategies. A report to the ACCOBAMS Secretariat, Monaco, February 2002, Section 8, 19 p.
24. M. Prideaux, Conserving Cetaceans: The Convention on Migratory Species and its relevant Agreements for Cetacean Conservation, WDCS, Munich, Germany, 2003, 24 pp.
25. G. Bearzi, Interactions between cetacean and fisheries in the Mediterranean Sea. In: Nortarbartolo di Sciara (Ed.), Cetaceans of the Mediterranean and Black Seas: state of knowledge and conservation strategies. A report to the ACCOBAMS Secretariat, Monaco, February 2002. Section 9, 20 pp.
26. R.R. Reeves, A.J. Read, G. Notarbartolo di Sciara, Report of the Workshop on Interactions between Dolphins and Fisheries in the Mediterranean: Evaluation of Mitigation Alternatives. ICRAM Workshop, Rome, Italy, May 2001. Doc. SC/53/SM3 presented at the 53rd Meeting of the International Whaling Commission, London, July 2001.
27. A.A. Silantyev, Black Sea Coast of the Caucasus in Agricultural and Commercial Respects. Issue 1. Dolphins Fishery off the Caucasian Coasts. Department of Agriculture, St Peterbourg, (1903).
28. V. Pavlov, A. Artov, T. Zhuravleva, Impact of fishing on Black Sea dolphins off the Crimea coasts. Pp. 41-43 in: B. Öztürk (Ed.), Proceedings of the First International Symposium on the Marine Mammals of the Black Sea (Istanbul, Turkey, 27-30 June 1994), ACAR Matbaacilik A.S., Istanbul, 1996.
29. S.G. Bushuyev,. Depletion of forage reserve as a factor limiting population size of Black Sea dolphins. Pp. 437- 452 in: Ecological safety of coastal and shelf areas and a composite utilization of shelf resources, Proc. Marine Hydrophysical Institute, Sevastopol, 2000.
30. M. Klinowska (Comp.), Dolphins, Porpoises and Whales of the World. The IUCN Red Data Book. IUCN, Gland and Cambridge, viii + 429 p, 1991.
31. B. Öztürk (Comp.), Black Sea Biological Diversity: Turkey. UN Publ., New York, 1999.
32. Birkun, A., Jr., Interactions between Cetaceans and Fisheries in the Black Sea,. In: G. Notarbartolo di Sciara (Ed.), Cetaceans of the Mediterranean and Black Seas: state of knowledge and conservation strategies. A report to the ACCOBAMS Secretariat, Monaco, February 2002, Section 10, 2002.
33. S.V. Krivokhizhin, A.A. Birkun, Jr., J.V. Nessonova, Prey species of Black Sea cetaceans. P. 229 in: P.G.H. Evans, R. Pitt-Aiken and E. Rogan (Eds.), European research on cetaceans – 14 (Proc. 14th Annual Conf. European Cetacean Society, Cork, Ireland, 2-5 Apr 2000), ECS, Rome, 2000.
34. D.P. Andrianov, V., Bulgakova, The factors determining the abundance of the Black Sea anchovy. Pp. 13-15 in: B. Öztürk (Ed.), Proceedings of the First International Symposium on the Marine Mammals of the Black Sea (Istanbul, Turkey, 27-30 June 1994), ACAR Matbaacilik A.S., Istanbul, 1996.