Occurrence and Distribution of Cetaceans in the Northeastern Part of the Black Sea.

Studies of Black Sea cetaceans were carried out in September 2018 (11 days, 799 km of the survey route) and June 2019 (12 days, 1174 km of the survey route). The research vessel followed a survey route off the Caucasian coast of the Black Sea from Anapa to Adler at a distance of up to 165 km from the coast. There were 103 sightings of cetaceans (548 individuals) in 2018 and 347 sightings (1280 individuals) in 2019. Three species were recorded: common dolphin, bottlenose dolphin, and harbor porpoise; their ratios were 78.1 : 20.8 : 1.1 in 2018 and 90.1 : 7.1 : 2.8 in 2019. Common dolphins were sighted everywhere; in June, they were encountered more frequently in the coastal water area; in September, in the open sea. This was probably preconditioned by the availability of prey. Bottlenose dolphins and harbor porpoises performed short-distance seasonal migrations and preferred to remain in local coastal habitats. [ABSTRACT FROM AUTHOR]