Biota of floodplain lakes of the Ob river in the lower reaches of the Novosibirsk hydroelectric power station

Abstract

An overview of typical lakes of the floodplain system of the river is presented. Ob in the lower reaches of the Novosibirsk hydroelectric power station, data on the species structure and biomass of fish, zoobenthos and zooplankton are presented. Most lakes of the Ob floodplain have an elongated channel-like shape and have a constant hydrological connection with the channels of the Ob River. The area of the lakes does not exceed 40 hectares. According to the research results, the zooplankton of the lakes is represented by 20 species, the total number of zooplankton varied from 50 620 copies/m3 (Kolkhoznoye lake) to 477 740 copies/m3 (Bolshoy Elbak lake). The biomass of zooplankton in the surveyed lakes was 2488–3443 mg/ m3. 24 species were found in the zoobenthos of floodplain lakes, the total number of zoobenthos varied from 887 copies/m2 (Kolkhoznoye lake) to 3468 copies/m2 (Bolshoy Elbak Lake). The biomass of zoobenthos varied from 3,100 to 38,152 g/m2. According to the indicators of zooplankton biomass, lakes are characterized as reservoirs of beta-mesotrophic type, i.e. of the middle productivity class, according to the classification of feeding capacity — as reservoirs above the average feeding capacity for planktophagous fish. On the development of zoobenthos lake. Vilannoe refers to high–fed, eutrophic type reservoirs, high productivity class, Kolkhoznoye lake — to medium-fed, mesotrophic type reservoirs, moderate productivity class, Bolshoy Elbak lake refers to high-fed reservoirs of mesotrophic type of medium productivity class. The main species of ichthyofauna of floodplain lakes are the firebrand rotan (Perccottus glenii) and silver carp (Carassius gibelio). The biomass of the ichthyofauna is 45.1–100.9 kg/ha. As a result of the study, it was revealed that commercial development of the ichthyofauna of these lakes is impractical, but their use for commercial fish farming is possible.