Herring survey in the Northern Caspian

 

Trawl and net stations were carried out in the waters of the western part of the Northern Caspian from Tyuleniy Island to the Rakushechnaya Gobachek Bank.

 

The composition of the net and trawl catches was represented by anadromous, marine and semi-anadromous fish species. Single specimens of the Russian sturgeon stellate sturgeon were found in the catches. Herring were represented - Dolginskaya herring, Caspian puzanok and Agrakhan herring, other marine fish - atherina, common sprat, gobies and mullet, from semi-anadromous fish - bream, roach and crucian carp.

 

During the work, the species composition of the catches was determined, materials were collected for subsequent qualitative and quantitative assessment of the stocks, some fish were subjected to a full biological analysis, the rest were returned to their natural habitat alive.

 

Mass concentrations of fish were observed in the western part of the surveyed water area, in the zone of action of the Volga stream, in the waters immediately adjacent to the exit of the Volga-Caspian Sea Shipping Canal and surrounding Tyuleniy Island. At stations in the eastern part of the surveyed water area, at depths of 7 m and more, the catches were low, represented mainly by semi-anadromous fish species.

 

During the survey, samples were taken at each station for hydrological, hydrochemical, toxicological, hydrobiological, trophological, physiological, molecular genetic, microbiological and ichthyopathological studies. Along the vessel's route, a route census of the Caspian seal was carried out.

 

The materials obtained during the survey will be used to assess the state of fish stocks, the quality of their habitat, and to prepare forecast materials on the values ​​of the TAC and the recommended catch for 2027. The results of the survey will make it possible to clarify the changes taking place in the northern part of the Caspian Sea in the current conditions of its regression.

 

Press Service of VNIRO