The impact of fishery on the state of populations of the European whitefish Coregonus lavaretus in Lake Imandra

Abstract

The impact of fishery on the state of populations of the European whitefish Coregonus lavaretus in Lake Imandra, the largest water body of the Kola Peninsula, is considered. The retrospective analysis of catches in the period of 1930 to 1998 indicated that the consequences of an uncontrolled fishery are comparable with the effects of intensive technogenic pollution. As a result of the intensive commercial load on the water body over many decades, the number of age groups decreases, the size-weight indices in fish change, an early maturation at sizes small for the species is observed, and the population structure becomes more simple. Against the background of the improving environmental quality, the numbers of fish under the effects of the uncontrolled amateur and poaching fisheries continue to decrease, which leads to the change of the nucleus of the fish proportion of the community and the change of dominant species.