Comparative Characteristics of the Volga-Akhtuba Watershed Hydrobiocenoses According to Indicators of Biodiversity and Saprobity

Abstract

The article presents a quantitative and qualitative determination of the composition of the plankton zoocenosis reservoirs of the Volga-Akhtuba interfluves. Biological diversity was studied on zootsenotic level using the indices of biodiversity. The comparative characteristic of reservoirs on the above mentioned parameters. Sampling was carried out at the boundary of the conservation Park Volga-Akhtuba interfluves. As the material for this work there were used samples of zooplankton collected in the summer of 2016. Thus, the results of sample analysis detected from 13 up to 19 species of planktonic invertebrates, among which dominated mainly copepod crustaceans ( Eucyclops macruroides ). The dynamics of their abundance and biomass in all the study reservoirs is almost similar, due to the biology of organisms that are dominant in hydrobiocenoses. The calculation of biodiversity indices revealed that the richest were the lakes, where the Margalef index varied from 1.6 to 1.2 units, and the index of Shannon-Weaver, reflecting the complex structure of hydrobiocenosis, had high values (2.97 bits/unit and 2.74 bits/mg). The Simpson index demonstrating dominant position of different species in zooplankton community, was also higher in the lakes. Using selected indicator organisms there were calculated indices of waited average saprobity, according to which water reservoirs of the invironmental park "Volga-Akhtuba interfluves" can be characterized as moderately polluted. i.e., in zooplankton community the leading role belongs to organisms actively participating in the self-cleaning processes of the water reservoir.