Persistent organic pollutants in hydrobionts in river ecosystems of Crimea

For the first time, the content of persistent organic pollutants (DDT, its metabolites DDE and DDD, and six indicator congeners of polychlorinated biphenyls) was determined in several fish species (Alburnoides maculatus, Squalius cephalus, Neogobius fluviatilis) and shrimp (Palaemon adspersus) in three small Crimean rivers: the Alma, Belbek, and Chernaya. It was revealed that hydrobionts accumulated these substances, the composition and concentration levels of which varied significantly in different areas. In the Crimean spirlin (Alburnoides maculatus) in the Belbek River and the silver prussian carp (Carassius gibelio) in a lake located in the lower catchment area of the Alma River, the highest concentrations of DDE, exceeding maximum permissible concentrations, as well as a high environmental risk from its impact, were determined. PCBs were either not detected or detected at low concentrations in fish tissue in rivers Alma and Belbek, indicating the absence of industrial sources of pollution, while agricultural pollution remains significant. A difference in the accumulation of persistent organic pollutants was revealed in the organs of the shrimp from the Chernaya River: the concentration of DDE and PCBs in the caviar was 10 to 20 times higher than in the muscle tissue. In the Chernaya River, a high environmental risk associated with the impact of congeners PCB 138 and 153 on the shrimp population was identified.