Adaptation of Fish Metabolism to Thermal Pollution of Subarctic Lake Imandra

Abstract

Kola nuclear power plant, which discharges warm water into one of the bays of sub-arctic Lake Imandra, significantly changes the fish habitat, creating temperature gradient from 2 to 8°C compared to water temperature in the other part of the lake. The permeation, metabolism and bioaccumulation of elements in the stenothermal cold-water species (Coregonus lavaretus L.) in warm water impact zone are characterized. One of the main adaptation mechanisms of ionic regulation is the intense metabolism of Na due to the high respiratory activity of whitefish in warmer water. This feature is associated with elevated accumulation of Rb and loss of Se, Mo, and Si. At elevated temperatures, the main metabolic need is caused by Se deficiency. An extensive metabolism of selenoproteins involves risks of toxic effects and bioaccumulation of Hg, As and Cu with an increase of existing stressor or appearance of new ones.