ИХТИОПЛАНКТОН ПРИБРЕЖНЫХ АКВАТОРИЙ ЮГО-ВОСТОЧНОГО КРЫМА В ЛЕТНИЙ НЕРЕСТОВЫЙ СЕЗОН 2023 Г.

Abstract

Background. The last systematic studies of ichthyoplankton in the coastal waters of Southeastern Crimea were carried out 30 years ago. However, despite the high importance of this aquatic area for fish reproduction, the current data on it remain extremely scarce. Relevance. Monitoring surveys of ichthyoplankton carried out by the Karadag Biological Station make it possible to analyze the current state of ichthyoplankton complexes and predict the success of recruitment to the natural fish populations. The aim of this article is to analyze the data obtained during monitoring studies of ichthyoplankton in the coastal waters of Southeastern Crimea during the summer spawning season of 2023. Methods. Ichthyoplankton samples were collected in May–September 2023 in the coastal waters along the south- eastern part of the Crimean Peninsula over a depth of 3 to 20 m. Fifteen expeditions were carried out in the aquatic area of the Karadag Nature Reserve, in Tikhaya (Quiet) Bay and Lisya (Fox) Bay. Results. Eggs and larvae of 30 fish species belonging to 20 families have been identified. The average number of eggs was 145.9 pcs./100 m3, and for larvae it was 15.1 ind./100 m3. Species similarity index for the summer ichthyoplankton in 2020 and 2023 was 0.79. Diversity indices in 2023 decreased by an average of 1.2 times compared to 2020 due to the pronounced dominance of anchovy, which had not been previously observed. Conclusion. The highest number of species (28) was recorded in the coastal waters of the Karadag Nature Reserve: the abundance of eggs was 153.2 pcs./100 m3, and the abundance of larvae was 12.0 ind./100 m3. The lowest number of species (14) was observed in Tikhaya (Quiet) Bay: the abundance of eggs was 113.0 pcs./100 m3, and the abundance of larvae was 7.7 ind./100 m3. In the samples, the eggs of Engraulis encrasicolus (52.0 %) and Mullus barbatus (20.6 %) prevailed. Among larvae, the most prevalent were those of anchovy (46.4 %) and hatched from demersal eggs of Chromis chromis, as well as the fish species belonging to the families Gobiidae, Blenniidae, and Labridae (40.2 %).