Abstract
<jats:p>Structural abundance indicators (abundance and biomass indices, relative abundance, frequency of occurrence) are considered, which make it possible to assess the importance of pike in the structure of fish communities on Lake Vishtynetsky. The spatial and temporal dynamics of pike abundance indicators for the period from 2029 to 2024 are analyzed. The analysis was carried out on the basis of materials from 7 460 gillnet catches and 1 004 pike specimens. The pike inhabits various biotopes and is found in the lake up to a depth of 45 m. Pike plays the most prominent role in the fish community of the epilimnion. Main part of biomass (77%) and numbers (73%) are concentrated here. Indicators of relative abundance and frequency of occurrence have a general trend to decrease with depth. The frequency of pike occurrence during the study period averaged 54%. Until 2017, pike was a constant species in the lake, and since 2018 it has been rare. The degree of pike dominance in the fish community has decreased significantly during the observation period. By now, the pike is numerically a secondary species. In terms of biomass, a subdominant occupies a place in the structure of the fish population. Pike stocks are in an unstable state. The dynamics of pike abundance indicators as a whole is characterized by significant variability and cyclical fluctuations. The probable reasons for the decline in pike numbers in the lake are the increasing pressure from angling and the drop in water levels as a result of the destruction of the dampers of the regulator lock on the Pisse River.</jats:p>