VNIRO specialists conducted an ichthyological survey of sterlet in the Irtysh River

 

The expedition was part of a state monitoring program; the specialists assessed the intensity of the autumn migration of sterlet and other fish of the common group to their wintering grounds.

 

During the study, the ichthyologists conducted mass measurements of the caught specimens and a biological analysis. This included measuring the length and weighing of the fish, visually determining sex, gonad maturity, fat content, and the fullness of the digestive tract. The age structure of the populations will be determined during office processing in the branch's laboratories.

 

Furthermore, hydrobiological and hydrochemical samples were collected in various parts of the Irtysh to assess the state of the food supply and habitat. Daily monitoring of dissolved oxygen levels was conducted at six stations.

 

The Siberian sterlet is widespread in the Ob-Irtysh basin. It forms several relatively isolated stocks. The most numerous and commercially important of these stocks inhabit the middle reaches of the Ob River and the lower and middle reaches of the Irtysh River. The results of fisheries research will form the basis for forecasting the permissible catch of this valuable Siberian fish species.

 

VNIRO Press Service