COMPARATIVE ANALYSIS OF LONG-TERM ALTERATIONS IN STRUCTURAL ORGANIZATION OF ZOOBENTHOS UNDER PERMANENT ANTHROPOGENIC IMPACT (CASE STUDY: SEVASTOPOL BAY, CRIMEA)
The results of benthic survey of soft bottoms in the Sevastopol bay had been performed in 2001 are presented. This bay is under permanent technogenic impact and is being considered as one of the most polluted areas along the coastal part of Crimea. The peculiarities of quantitative development of macrobenthic assemblages were characterized, and taxa which define the structural organization of assemblages were distinguished. In spite of strong influence of technogenic pollution, Sevastopol bay can be attributed to faunistically rich areas of Crimean coast and the Black Sea at whole. Using the methods of multivariate statistical analysis, suites of 7 - 8 environmental variables (from the 32 ones considered in the analysis) that best explained the observed benthic spatial distribution pattern were identified. It was noted that chloroform-extracted bitumens, which traditionally are being attributed to the most important abiotic factors affecting to bottom communities, were not included into set of the most significant variables influencing on macrobenthos. Comparative analysis of materials which had been collected in extremely far-separated time periods (1928 - 2001) allowed revealing availability of long-term tendencies: increasing of average benthos biomass values in the bay; and change in trophic structure of benthos when detritus-feeders became prevail. Such alterations can be considered as one of the way of adaptive response of the bay's ecosystem under growing of organic enrichment in Crimean coastal waters.