The ecological condition of coastal waters off the Heracles Peninsula (Crimea, the Black Sea)

Abstract

The results of the long-term monitoring of coastal waters off the Heracles Peninsula (Crimea, the Black Sea) are presented. The abiotic and biotic parameters, indicating the ecological condition of the coastal zone, have been studied. The following parameters have been measured by standard methods: water temperature, illuminance, concentration of particulate matter, organic matter, primary production, intensity of biotic reproduction of particulate matter, phytoplankton and meroplankton species diversity, abundance, and biomass, as well as shell morphometrics and sex ratio in mussel Mytilus galloprovincialis Lam. It has been found that upwelling water circulation is typical for the coastal waters off the Heracles Peninsula. The mean annual sea surface temperature over the study period 2000-2016 proved to be 2.7°C higher than that in the early 20th century. The maximum values of phytoplankton primary production are associated with inner waters of coves and with increased Twater and Emax values. A reduction in phytoplankton and meroplankton diversity and a dominance of eurybiontic species have been recorded from the waters subject to anthropogenic impacts. The most pronounced shift of sex ratio toward predominance of M. galloprovincialis males and a high mussel H/L shell index are observed in waters with increased technogenic load. The taxonomic structure of phytoplankton and meroplankton, sex ratio, and morphometric parameters of bivalves are the sensitive tools of ecological monitoring to assess the condition of the surrounding aquatic environment.