Environmental aspects of the effectiveness of fish-protection structures such as umbrella on the Irtysh river in the Omsk region

Abstract

It is generally accepted that water intake facilities used in fishery reservoirs adversely affect the state of fish stocks — a large number of juvenile fish fall into them along with water. The study of environmental factors, hydrological conditions and design solutions affecting the effectiveness of fish-protection structures (devices) such as umbrella installed on bottom water intakes in the form of suction or gravity pipes of pumping stations is of great importance for preventing the death of juvenile fish. Studies of the effectiveness of umbrella fish-protection devices were carried out in 2020–2022 at two water intake facilities located on the Irtysh River within the boundaries of the Omsk Region. Field studies at each water intake were carried out during four calendar seasons (spring, summer, autumn, winter). The collection of materials on the species, size and quantitative composition of larvae and juveniles of fish was carried out before the fish-protection installation, in coastal wells and near the shore in the area of water intake to study the background state of the concentration of juvenile fish around the clock with an interval of 4 hours. Juveniles and larvae of fish in the area of water intake were localized exclusively along the coast, where they were caught. Juveniles and larvae of fish were not recorded at other fishing points. Studies have shown that the location of the water intake umbrella heads in a place remote from the shore, where the larvae and juveniles of fish are practically not found, as well as the low flow rate in the water intake devices, ensure high efficiency of fish-protection devices of channel water intakes.