Biodiversity of benthic animal communities and quality of waters in the Neva estuary under anthropogenic stress

Abstract

In the eastern part of the Gulf of Finland 129 in the Neva Bay 127 species and superspecies taxa of benthic animals were found. In total in 1994–2014 188 taxa of benthic animals were recorded in the estuary of the Neva River. Among these 68 are common for the Neva Bay and the eastern Gulf of Finland. At present zoobenthos communities in the estuary are dominated by eurybiont indicator species inhabiting “polluted” and “dirty” waters responding positively to an increase of organic pollution and eutrophication of the ecosystem and resistant to high concentrations of heavy metals and pollutants. Integrated mean assessment of water quality over the entire Neva Bay by means of (IP') (for the 1994–2014) remained relatively stable during the whole period, waters (except in 2006) were assessed as “polluted”. In the health-resort zone of the eastern Gulf of Finland IP' changed during the period of studies from 67.4 to 71.5% characterizing the quality of waters as “polluted-dirty”, which is one class lower than waters of the Neva Bay. As a result of pollution species diversity of benthic animals in the resort zone of the eastern Gulf of Finland is notably lower than in the Neva Bay.