Summer and autumn distribution of fish in Lake Glubokoe

Seasonal (summer and autumn) and diurnal (day and night) distribution of fish in Lake Glubokoe (Moscow oblast) was analyzed using vertical and horizontal scanning research hydroacoustic systems. At the beginning of summer the distribution of the fish in lake is broad and homogeneous whereas in autumn it is more compact. Pelagic aggregations of the fish are aggregated mostly in the central part of this lake both in summer and autumn during the day. However, at night they scattered throughout its whole area. The pattern of the fish distribution depends on the cycles of the abiotic conditions and the concomitant pattern of trophic and defensive relationships.