Determining the Consequences of Climate Change for Aquatic Ecosystems Using Bioassay Methods: a Review

The article describes scientific and methodological possibilities of bioassays in the field of studying consequences of climate change for water bodies and aquatic organisms inhabiting them. Using fish aquacultures, it was found that an increase in water temperature changes biochemical parameters of internal environments of organisms, affects their behavior and the number of offspring. A number of biogeochemical transformations of aquatic ecosystems are predicted: a decrease in water pH, mineralization of organic matter in bottom sediments, release and increase in bioavailability of compounds of potentially toxic elements. Using bioassay methods on monocultures and laboratory microcosms, it was shown that pessimal temperature values and a cascade of accompanying changes will lead to a restructuring of the community of aquatic organisms, changes in the habitats of organisms, and the disappearance of stenothermic species. The reality of such scenarios is confirmed by paleodata and phenomena that are already happening.