Macrozoobenthic Population under Heavy Anthropogenic Impact: Coastal Area of Vladivostok (Peter the Great Bay, Sea of Japan)

In total, 65 macrozoobenthic species belonging to 14 taxa were found at the area studied. Polychaetes were dominant in number of species (36), and then bivalves followed (8). Polychaete worms were the most frequent (100 %), ophiuroids occupied the second place (54.5 %), and then Bivalvia, Nemertea, Gastropoda, Phoronida, Priapulida went after (27.3- 45.5 %). Minimal values of ecological parameters were shown to locate to the most contaminated regions – Golden Horn and Diomid Inlets – that reflected a high level of anthropogenic impact. Worsening of ecological state of benthos at these areas and in the east part of Amursky Bay occurred due to not only high level of chemical contamination, but oxygen deficiency (and complex of factors connected) that is permanent in the north part of Golden Horn Inlet and seasonal off the western coast of Murav'eva-Amurskogo Peninsula. Five macrozoobenthic communities were revealed. They were A. pacifica + Sch. japonica + C. capitata, O. sarsi vadicola + M. scarlatoi, O. sarsi vadicola + E. tenuis and a monodominant association of Phoronopsis sp. Differentiation of these communities at the area studied occurred due to effects of anthropogenic factors mainly. Communities of poor species composition were developed under extreme and heavy chemical contamination and almost all species found in these groups were positive indicators of pollution and eutrophication. Macrozoobenthic communities became more diverse, and various representatives of bottom fauna appeared side by side with positive indicators under decrease of anthropogenic impact. Benthic associations formed in sites with bad and poor ecological status were shown to be less changeable than those developed under moderate and even good ones.