Open AccessVORTEX STRUCTURES (EDDIES) IN THE RIVERBED DEPRESSION AND FISH DISTRIBUTION
Author(s) -
Andrey Aleksandrovich Chemagin
Publication year - 2018
Publication title -
vestnik astrahanskogo gosudarstvennogo tehničeskogo universiteta. seriâ: rybnoe hozâjstvo
Language(s) - English
Resource type - Journals
eISSN - 2309-978X
pISSN - 2073-5529
DOI - 10.24143/2073-5529-2018-4-96-103
Subject(s) - percidae , vortex , cyprinidae , fishery , fishing , sturgeon , eddy , geology , fish <actinopterygii> , oceanography , hydrology (agriculture) , environmental science , geography , turbulence , biology , perch , meteorology , geotechnical engineering
The article highlights the studies carried out in summer using the hydroacoustic method from the small boat with control fishing in the lower reaches of the Irtysh in the Gornoslinkinskaya riverbed depression. The method of research is based on using computerized hydroacoustic software and hardware complex “PanCor” (Promgidroakustika, LLC). Hydroacoustic records were processed in the laboratory. The features of fish distribution in a turbulent flow of the riverbed depression at the river bend have been recorded. Significant accumulations of fish in the areas of vertical vortex structures - eddies have been registered. Eddies are registered both visually and hydroacoustically. The recorded vortex structures are formed as a result of the hydrological features of the channel of the river studied section. There has been established a significant ( p 0.70) between the number of fish species from all taxonomic groups (Cyprinidae, Percidae, Coregonidae, Esocidae, Lotidae, Acipenseridae) and the height of the water column in vortex structures. The number of fish in the vortex zones reliably exceeds that number outside these zones; for Cyprinidae by 2.61times, Percidae - 1.47, Coregonidae-Esocidae - 2.80, Acipenseridae-Lotidae - 2.50. It has been stated that in the zone of eddies the percentage of small individuals and medium size fish ( 20 cm), on the contrary, the percentage is larger outside the vortex zones. The accumulation of fish in the whirlpool part of the riverbed depression occurs in the result of choosing the necessary habitat conditions that have a predictability component, as well as due to temporary drawing and holding the fish in the vortex zone.