Distribution of Pelagic Fish in Lake Sevan under the Effect of Hydrophysical Factors

Based on the materials of field observations and calculative methods, the peculiarities of distribution of pelagic fish in Lake Sevan are characterized under the effect of the main hydrophysical factors. The zones of stable localization of fish aggregations in the water circulation system, as well as their preferred location in the water column of the lake, are detected. A vertical distribution of aggregations is determined by the thermocline position, water temperature, and content of dissolved oxygen. The mechanisms for the formation of stable fish aggregations under the effect of horizontal currents are proposed.