The Volga-Caspian branch of VNIRO continues research to assess the effectiveness of natural fish reproduction

 

The current speed fluctuated from 0.5 to 1.1 m/s at a water temperature of 20.7 to 24.9 °C. Fishing for rolling larvae of black-backed herring and sturgeon was carried out using IKS-80 ichthyoplankton nets. A total of six daily stations were conducted.

 

Since mid-July, work has begun to study the migration of juvenile anadromous (sturgeon) fish species using a 4.5-meter bottom trawl with a gas-sieve insert; grown-up juveniles (yearlings) of sturgeon species weighing up to 10 g were caught. The by-catch included white bream and blue bream of various sizes.

 

On the vessel m/v "Raskat", work was continued to count and distribute juveniles of semi-anadromous and inland fish in water bodies of the western part of the Volga River delta - on the Main, Gandurinsky and Kirovsky banks. The feeding conditions of late-spawning fish species were studied, isolated cases of their spawning were noted, the feeding conditions of larvae and grown juveniles in the current conditions of the low-water period were assessed. During the work, the state of the food supply for young fish was also studied (zooplankton samples were taken), soil and water samples were collected to study the quality of the habitat of aquatic bioresources.

 

The collected monitoring materials will be used to assess the effectiveness of natural reproduction, fattening conditions in 2025 and the effectiveness of fish reclamation measures carried out on water bodies in the Astrakhan Region.

 

Press Service of VNIRO