About Stranding and Accidentally Caught Cetaceans in the Black Sea: Death Reasons, Feeding Characteristics and Pregnancy Status

Abstract

This study was carried out to determine stranding levels, dead reasons and some reproduction features and diet of the Black Sea’ cetacean species (harbour porpoise, Phocoena phocoena and common dolphin, Delphinus delphis) Rize coast in the Black Sea. By caught cetaceans (71 harbour porpoise and 4 common dolphins) were drowned entangled in the nets and they did not damage the turbot nets. Stranding levels of the Black Sea’ cetaceans (6 harbour porpoise and 4 common dolphins) were 60% P. phocoena and 40% D. delphis. Probable causes of death of stranding cetaceans were determined as asphyxia and marine pollutions. Mating of P. phocoena begins between June and July and calving takes after May. A total of 52 harbour porpoise and 6 common dolphin stomach examined for diet analyzes. Harbour porpoises feed mainly anchovy (N = 86%; FO = 63%), whiting (N = 12%; FO = 25%) and horse mackerel (N = 2%; FO = 11%), and also common dolphin feed mainly anchovy (N = 8%, FO = 43%) and horse mackerel (N = 5%; FO = 43%).

Keywords

• Cetacea,by catch,fisheries,Black Sea.

Karadeniz’de Karaya Vuran ve Kazara Yakalanan Yunuslar (Cetacea) Hakkında: Ölüm Nedenleri, Beslenme Özellikleri ve Gebelik Durumu

Abstract

Bu çalışma, Kalkan dip uzatma solungaç ağlarıyla yapılan avcılıkta Karadeniz’de yaşayan iki yunus türünün (Mutur, Phocoena phocoena ve Tırtak, Delphinus delphis) karaya vuran miktarı ve ölüm nedenleri ile bazı üreme ve beslenme özelliklerinin belirlenmesi için Rize kıyı şeridinde yürütülmüştür. Dip uzatma kalkan ağlarıyla kazara yakalanan yunuslar (71 Mutur ve 4 Tırtak) ağlara dolanarak boğulmuş ve yunuslar kalkan ağlarına zarar verememiştir. Karaya vuran yunusların (6 Mutur ve 4 Tırtak) %60’ı P. phocoena, %40’ı ise D. delphis türüdür. Karaya vuran yunusların muhtemel ölüm sebeplerinin avcılık sırasında ağlara kazara takılıp boğulmaları ve deniz kirliliği olduğu belirlenmiştir. P. phocoena türü Haziran ve Temmuz aylarında çiftleşmeye başlamakta, Mayıs’tan sonra ise doğum gerçekleşmektedir. Çalışmada 52 Mutur ve 6 Tırtak midesi incelenmiştir. Hem sayısal varlık hem de bulunuş frekansı açısından Mutur başlıca Hamsi (% N = 86; %FO = %63), Mezgit (% N = 12; %FO = %25) ve İstavrit (% N = 2; %FO = %11) balıkları ile Tırtak ise Hamsi (%N = 8, %FO = 43) ve İstavrit (%N = 5 %FO = 43) balıklarıyla beslenmiştir.

Keywords

• Cetacea,kazara yakalanma,balıkçılık,Karadeniz.

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