Open AccessINFLUENCE OF ABIOTIC FACTORS ON FEATURES AND DISTRIBUTION DYNAMICS OF FISH IN SMALL TRIBUTARY OF IRTYSH RIVER
Author(s) -
Andrey Aleksandrovich Chemagin
Publication year - 2020
Publication title -
vestnik astrahanskogo gosudarstvennogo tehničeskogo universiteta. seriâ: rybnoe hozâjstvo
Language(s) - English
Resource type - Journals
eISSN - 2309-978X
pISSN - 2073-5529
DOI - 10.24143/2073-5529-2020-4-66-80
Subject(s) - tributary , hydrology (agriculture) , floodplain , environmental science , turbidity , drainage basin , period (music) , geology , geography , ecology , oceanography , biology , physics , cartography , geotechnical engineering , acoustics
The article focuses on the studies carried out in the flooded floodplain of the small river Varpak in the basin of the lower Irtysh during the spring flood (in May). The influence of abi-otic factors on the distribution of fish, including juveniles of cyprinids, percids and pike was analyzed. It was found that during the research period there was a direct correlation between the fish density and the temperature and water level, i.e. the fish density increased, as well as the mentioned indicators. There was found the regularity of decreasing the proportion of percids and fish density along with increasing water turbidity in the periods of the southern (S) and south-western (SW) winds, which is stipulated by the wind and wave fish set-down and their independent movement to the shallow areas of the flooded floodplain; In the periods of the north (N) and northeast (NE) winds the fish density increased along with water turbidity, i.e. the fish moved from the shallow water zones to the open water area. The investigated section of the Varpak River is open to the winds of the mentioned directions due of its location and relief. When considering the direction of the fish density distribution during the period of wind events S, SW, N and NE, there has been registered the similarity between the wind direction and the fish distribution in the water area of the floodplain. As a result of the analysis during the observation period the influence of the turbidity factor on the distribution of fish is noted; the greater turbidity, the greater the proportion of cyprinids and the lower the proportion of percids, which can be explained by the specific behavior of these groups of fish. Thus, there is a direct and indirect effect of a number of environmental factors (temperature and water level, wind phenomena and turbidity) on the characteristics and dynamics of fish distribution in the flooded floodplain of the river in the spring period