Comparative analysis of biological indicators and species composition of ichthyofauna of the northern part of the Agrakhan Bay
Keywords:Northern part of the Agrakhan Bay, ichthyofauna, reproduction, semi-anadromous, nonmigratory and lake-river fish
The northern part of the Agrakhan Bay plays a major role in restoration of commercial fish stocks in the Tersko-Caspian region of the Republic of Dagestan. Here the natural bioresources of anadromous, semi-anadromous, non-migratory and lake-river fish species are being reproduced, and up to 600 million young fish species are being replenished annually. The article presents comparative data on the current state of natural reproduction of the main fish species, qualitative and quantitative changes in the structure of ichthyofauna that have occurred in this bay. As a result of this study, it has been determined that commercial species such as Caspian kutum, wels catfish, asp and vimba vimba have practically disappeared in the northern part of the bay, while the age and size-weight parameters of other fish species have increased. The reason for this situation is primarily the unfavourable hydrological regime during the spring-summer floods, which does not meet the necessary requirements for fish reproduction.