Годовая динамика численности, биомассы и выживаемости меропланктона в Севастопольской бухте, Черное море

Обобщены данные по видовому составу, численности, биомассе и выживаемости меропланктона в Севастопольской бухте (Черное море). Анализ изменений гидрохимических и гидрологических условий в 1998 и 1999 годах показал их влияние на биологические особенности представителей меропланктона разных таксономических групп и размеров тела. Дискриминантный анализ дал возможность обнаружить в бухте две хорошо различающиеся пелагические подсистемы. Сравнение жизнеспособности меропланктона за период 1989-1999 гг. выявило её снижение у представителей Polychaeta и Cirripedia.The first comprehensive data on species composition, abundance, biomass and survival (living/dead ratio) of meroplankton in Sevastopol Bay (Black Sea) are presented. Marked differences were observed between the years 1998 and 1999, and these could be attributed to the hydrology and the eutrophication status of the different parts of the Bay. Shannon index and selected community parameters (number of species, biomass, numbers of individuals) indicated that South Bay was the worst affected part of the Bay with the greatest eutrophication impact on the meroplankton. The early larval stages of the barnacle Balanus improvisus and of the polychaete Polydora sp. were the most sensitive to presumed environmental stresses. It is suggested that the mortality of certain ontogenetic stages of the meroplankton can be used as sensitive indicators of ecosystem health with good spatial discrimination. The canonical correlations between biological and environmental variables ranged from 86 – 87 %. Discriminant functions defined two well-defined subecosystems in the Bay. Long-term comparison with 1989/90 data for the Bay outlet showed that molluscan larval mortality had remained unchanged, while that of Polychaete and Cirripedia had more than doubled, suggesting that they could be sensitive to increased eutrophication in Sevastopol Bay