The data obtained will form the basis for recommendations on fish stock management and reservoir protection: they will help determine the allowable catch volumes, plan measures for the reproduction of biological resources and make decisions to preserve the ecosystem in the long term.
During the expedition, scientists comprehensively studied the condition of the lake. They took hydrological samples at three control stations to track key parameters of the aquatic environment — temperature, transparency, oxygen content and other indicators on which the life of the inhabitants of the reservoir depends. In addition, the specialists took samples of phytoplankton, zooplankton and zoobenthos.: these food organisms play an important role in fish life.
Special attention was paid to ichthyological research. To get an objective picture of the species composition and distribution of individuals by size, scientists used multi—chain fishing nets - thanks to cells of different sizes, fish of different ages and sizes get into the catch. In total, the experts measured 457 specimens of roach and 327 specimens of perch: these data will allow us to assess the size and age structure of the populations ‑ to understand how many young and adult fish are in the lake and how successful the replenishment of the herd is.
In addition to mass measurements, biologists performed a complete analysis of 466 fish specimens of four species. Basic parameters were recorded for each individual: length, weight, sex, stage of maturity of sexual products, stomach filling and other important indicators. Such detailed work gives an idea of the health of fish, their satiety and readiness for reproduction.
Invertebrates were also not ignored: scientists analyzed 245 specimens of the narrow-toed crayfish (Pontastacus leptodactylus). These animals are an important element of the ecosystem, and their condition serves as a reliable indicator of the well—being of the reservoir.
By comparing data on fish, crayfish, and environmental parameters, experts can spot warning signs in time. For example, a decrease in the number of juveniles or a decrease in the average size of individuals may indicate an excessive strain on the population or a deterioration in habitat conditions. Thanks to the integrated approach, the study transforms from a simple "census" of lake inhabitants into a powerful tool for protecting its unique ecosystem.
VNIRO Press Service
