РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ АЗОВСКИХ ПОПУЛЯЦИЙ ОСЕТРОВЫХ РЫБ ПРИ ОСУЩЕСТВЛЕНИИ МОНИТОРИНГА ПРОМЫСЛА СТАВНЫМИ ОРУДИЯМИ ЛОВА У КУБАНСКОГО ПОБЕРЕЖЬЯ

Abstract

Introduction. After depletion of the Russian sturgeon Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833 and stellate sturgeon Acipenser stellatus Pallas, 1771 stocks at the end of the 20th century, their abundance in the Azov and Black Sea Basin has been maintained through the release of the juveniles obtained by the means of artificial reproduction. Resulting from the strengthening protection of the aquatic living resources and gradually increasing number of the released juveniles, since 2014, as evidenced by the research studies, an increase in the population abundance of these fish species and their biomass is observed in the Azov Sea (from 42 t in 2015 to 998 t in 2022). Unstable state of the sturgeon populations in the coastal waters of the Azov Sea predicated the relevance of this work. Its aim was to investigate the distribution and age–length composition of the populations of the sturgeon fish species in the coastal waters of the Azov Sea. Methods. This study was based on the data on age–length composition collected over the course of the investigation of sturgeon by-catches in stationary pound nets in the coastal waters of the Azov Sea within an administrative unit Primorsko-Akhtarsky District (Yasensk and Achuevo Spits). According to its results, out of all sturgeon species, in the autumn season, the stellate sturgeon prevailed—53 %; the share of Russian sturgeon was 43 %, and for beluga sturgeon, it was 4 %. In summer, the Russian sturgeon share in the catches was 79 %, and for stellate sturgeon, it was 21 %. There have also been recorded some differences of the Russian sturgeon and stellate sturgeon length composition between the early spring and middle autumn, which can result from the fact that the sturgeon individual of greater length leave their wintering sites in the Azov Sea open waters earlier and sooner enter the coastal waters in spring. Conclusions. This study makes it possible to improve the assessment of the stock status and distribution for the sturgeon fish species in the Azov Sea.