СОВРЕМЕННАЯ СТРУКТУРА И ДИНАМИКА СООБЩЕСТВ РЫБ ПРИБРЕЖНОЙ ЗОНЫ ЮГО-ЗАПАДНОГО КРЫМА НА ПРИМЕРЕ БУХТЫ КАЗАЧЬЯ

The results of long-term ichthyological research in one of the largest bays on the southwestern coast of the Crimea, Kazach’ya Bay, are presented. The fish fauna includes 83 species belonging to 59 genera in 41 families, and according to this parameter it ranks top among bays of Sevastopol. The ecological and faunal composition of the fish population is analyzed. Marine fishes dominate in terms of diversity, contributing about 90 % to the total number of species, while the rest are relict Ponto-Caspian migratory and brackish-water species. During the study period, the invasion of 8 alien East atlantic and Mediterranean species and one intentional introduction of a Far East endemic (so-iuy mullet) into the azov-Black Sea drainage basin were monitored. The abundance of the alien species has increased noticeably, possibly owing to a rise in water temperature. The bulk of the fish fauna in Kazach’ya Bay is resident fish belonging to the demersal ecological group. The importance of the bay as spawning grounds and feeding grounds for fish of various ecological groups is emphasized. among the species registered in the bay, 48 are objects of commercial or amateur fishing, 9 species are included in the Red Data Book of the City of Sevastopol. Data on the spatial distribution, habitat preferences and species diversity of the five ichthyocenes of the bay are reported. It is concluded that the diversity of the fish fauna of the south-western coastal zone of the Crimean Peninsula is continuing to grow due to ‘mediterranization’, but at the same time there is a decrease in the abundance of native Ponto-Caspian migratory and brackish-water fish, and this process is typical for the Black Sea at large. It is proposed to set up nature protection areas in the waters of Kazach’ya Bay.