Variability of the mitochondrial control region in the populations of the Black Sea harbour porpoise (Phocoena phocoena relicta) in the Turkish Seas

Black Sea harbour porpoises (Phocoena phocoena relicta) are endangered animals and the population structure needs to be understood in order to elaborate effective conservation measures. Mitochondrial DNA sequences of 55 individuals of the harbour porpoise sampled between 1999 and 2013 in the Turkish Black Sea coast (33 western, 13 eastern), Istanbul Strait (2), Marmara Sea (5), Çanakkale Strait (1) and Aegean Sea (1), revealed 14 polymorphic sites, resulting in 15 different haplotypes. None of the haplotypes obtained in this study clustered with those of the Atlantic populations, consistent with previous findings. The Black Sea haplotypes sequenced had been previously detected from the Black Sea coast of Bulgaria, Ukraine, Georgia, and Turkey. Four haplotypes were recorded for the first time in Turkish waters. One haplotype which had been previously detected in the Northern Aegean Sea (Greece) was detected for the first time in the Black Sea, in two individuals. Six (4 western, 2 eastern part) unique haplotypes were found in the Black Sea samples. The most common haplotype in our data set was recorded in one individual stranded in Bodrum (southern Aegean Sea), and also in the Marmara Sea (4), Istanbul Strait (1) and Çanakkale Strait (1), supporting the idea that harbour porpoises from the Black Sea dispersed into the Aegean Sea through these straits. One of the samples from the Marmara Sea sequenced in this study had the same unique haplotype as found in four individuals from the same sea in earlier studies, strengthening the possibility of an isolated population in the Marmara Sea.