Salinity tolerance of macrozoobenthos communities in small rivers of the Middle and Lower Volga river basin

There was conducted a comparative analysis of the variability of the species structure of macrozoobenthos communities in the basin waterways of the Middle and Lower Volga with various levels of mineralization. On the basis of the ordination model sensitivity distribution of species along the gradient of salinity one carried out the selection of taxonomic groups in the conditions of realizable states of river ecosystems during salinity rate fluctuations. We consider the application of SPEARsalinity biotic index for the assessment of the effect of salinity on the benthic communities.