The resources of many commercial fish species in the aquatic areas of the rivers in Siberian region are currently on the verge of exhaustion. It is known that the Siberian sturgeon is included in the Red Data Book of the Russian Federation and was totally lost as a biological resource of the Ob basin. Results of research carried out in the aquarium show a cause-effect chain between the exploitation of hydroelectric power station and the environment. The previously undescribed mechanisms of ecotoxicity were detected. These mechanisms were mediated through the implementation of the neurotoxic effect. The model experiment proved that the excess of receipt metals in surface water of the river Ob and fluctuations of hydrothermal regime in the process of hydroelectric power station exploitation leads to increase of the level of lipoperoxidation and the stress inside a system of antioxidant protection in cells of brain tissue of sturgeon during the winter-spring period. The morphological, biochemical and physiological aspects of adaptation strategies of fish were explored on light-optical and ultrastructural levels.