TOXIC EFFECT OF PESTICIDES ON THE BIOTA OF FRESHWATER RESERVOIRS OF UKRAINE (REVIEW)

Purpose. To analyze scientific sources on the studies of toxic and lethal concentrations of pesticides on phytoplankton, zooplankton, zoobenthos and fish in current conditions of Ukraine. Findings. A review of works of a variety of scientists showed that pesticides with different chemical origins have disastrous effects on everyone without the exception of freshwater biota organisms. The article highlights the peculiarities of the toxic effects of pesticides of major chemical groups, which are used or stored in Ukraine. Their toxic and lethal concentrations for the major species of phytoplankton, zooplankton, zoobenthos and ichthyofauna reservoirs are considered. The data on basic features of behavioral reactions of aquatic organisms on poisoning by pesticides are provided. The basic structural and systemic diosrders of homeostasis of the organisms of aquatic biota are described. The effect of pesticides on phytoplankton needs further research, however, is was found that they have common feature as the disturbace of photosynthesis process and accumulation. In turn, this provoques kills in water bodies and poisoning of phytoplanctivorous fish. Zooplanktonic organisms are highly sensitive to pesticides; hence they can be used as an indicator of the state of fresh water. It was found that, pesticides depending on their concentration have different toxic effects on zooplankton organisms. The effect of pesticides on benthic organisms was little investigated. It is known that benthic communities respond to the presence of pesticide by changes in species composition, number of species, abundance and biomass of benthos in general and individual taxonomic groups of benthic invertebrates. The toxicity of pesticides for fish depends on their chemical nature, the form of the preparation, dose, fish species and age, water temperature and the content of oxygen and salts. In particular, juvenile fish are much more sensitive to the chemicals, and an increase in water temperature and a decrease in oxygen content results in an increase in pesticide toxicity. Practical value. The array of the generalized information on the toxic and lethal effects of pesticides will be important for scientists who investigate the biological risk of pesticides and their impact on basic categories of freshwater biota and, in general, for ichthyological and environmental research. The information on the peculiarities of the toxic effects of pesticides on fish is important in the conditions of increasing demand for fish products as a source of valuable proteins for humans.