The population status of Cardііdae (Bіvalvіa) as a bioindicator for water quality in the North-Western part of the sea of Azov

An attempt was made to evaluate the suitability of using mollusc populations from the family Cardiidae as a biological in-
dicator to monitor ecological water quality in the north-western part of the Sea of Azov. It is known that some qualitative indices of
mollusc populations reflect large-scale changes occurring in benthos communities of the region. In this research, the monitoring of
aquatic organisms was carried out using such indices as population density, age distribution dynamics, characteristics of behaviour,
etc. Temporal and spatial dynamics of these indices allow the detection of changes in environmental factors which in their turn
determine basic and crucial functions of water bodies. Among other molluscs, representatives of the family Cardiidae stand out for
their ability of rapid occupation of new locations (due to the presence of a pelagic larval stage), and their adult individuals are rather
tolerant to fluctuations in salinity and other factors. The aim of this research was to reveal the variability range for basic qualitative
characteristics of bivalve populations in the north-western part of the Sea of Azov and to estimate if these molluscs are suitable to be
bioindicators of the environmental status of the region.
Keywords: ecology, monitoring, bioindication, bivalves, the Sea of Azov.