DDT in Crimea coastal waters and blubber of Black Sea cetaceans

Abstract This research is based on the multi-year data on the distribution of organochlorine pesticides of the DDT group in the water of the coastal Black Sea areas of Crimea, obtained in expeditions of the “Professor Vodyanitsky” research vessel from 1999 to 2020. Study of content of DDT and its metabolites (DDTs) in the blubber of three species of Black Sea cetaceans that were astrand on the Black Sea coast from the 1980s to the 2020s was grounded on own and literature data. While there was an overall significant variability in ∑DDT content during the study period, there was a significant downward trend in their concentrations in the water of coastal areas of Crimea. Despite the significantly decreased DDTs pollution of the habitat of the Black Sea marine mammals over the last 10 years, high concentrations of DDTs were accumulated in their blubber, the maximum value of the sum of DDTs concentrations reached (163 µg/g of lipids) in the blubber of adult depleted bottlenose dolphin. The minimum concentrations were determined in the blubber of a newborn harbour porpoise female. In blubber samples up to 70% was of DDE, DDD - from 21 to 24%, and the concentration of the initial DDT varied from 6 to 14%. Based on the analysis of own and literature data, it is assumed that in the modern period, as compared to the 1990s, there is a downward trend in the content of the DDTs in the blubber of Black Sea cetaceans.