FORMATION OF QUANTITATIVE INDICATORS OF ZOOPLANKTON IN THE WATER HEATS OF THE LOWER REACHES OF THE DNIEPER WITH VARIOUS INTENSITY OF EXTERNAL WATER EXCHANGE

Abstract

The article deals with the formation of quantitative indices of zooplankton in
the floodplain water bodies of the lower reaches of the Dnieper in the spring,
depending on the intensity of external water exchange. Among the quantitative
characteristics of zooplankton for analysis were selected biomass and strength of
species. The calculated values of the external water exchange period served as
characteristics of the intensity of the change in water masses in the reservoir.
A reliable direct correlation between the period of external water exchange
and quantitative indicators of zooplankton organisms, in particular their strength
and biomass, has been established. The correlation coefficients are 0.58 and 0.83,
respectively.
Distribution of zooplankton taxonomic groups in the spring period 2016-
2018 years in the studied region floodplain waters with different periods of
external water exchange, has been considered. It is revealed that the intensity of
the water masses in the water bodies of the lower reaches of the Dnieper change
also influences the distribution of taxonomic groups of zooplankton. The most
sensitive to this parameter of the water ecosystem were the representatives of the
Rotatoria and Сladocera groups.
Key words: zooplankton, biomass, strength, period of external water
exchange, lower reaches of the Dnieper.