Organochlorine Pesticides in the Blubber of Cetaceans off the Crimean Coast of the Black Sea

A study of the levels of persistent organochlorine pesticides (OCPs) in marine mammals of the Black Sea in 2018–2022 revealed a statistically significant relationship of the accumulation levels with the sex of the animals (males were more contaminated than females) and with the age group (adults and adolescents were more contaminated than calves and newborns). The location of tissue sampling for analysis was also an important factor: OCPs accumulated more in dorsal than in caudal blubber. In blubber of Black Sea harbor porpoises and common dolphins, the mean concentrations of OCPs decreased in the order p, p'-DDE > β-HCH > p, p'-DDD > p, p'-DDT; in the common bottlenose dolphin, they decreased in the order p, p'-DDE > p, p'-DDD > β-HCH > p, p'-DDT. The most widespread and highly concentrated metabolite was found to be p, p'-DDE. The concentration of p, p'-DDD was markedly lower; significant tissue concentrations of p, p'-DDT were observed much less frequently than all other metabolites and were among the lowest of all metabolites. Based on an analysis of variations in the mean concentrations of the sum of DDT metabolites in Black Sea harbor porpoise tissues, as reported in literature sources, we can claim that there is currently a significant decrease in the concentrations of these toxicants.