The Kiziltash estuary ecological characterization (Krasnodar region) based on its hydrobiological parameters

The hydrobiological indicators of the Kiziltash estuary on the qualitative and quantitative composition of phyto-, zooplankton and zoobenthos communities are presented. The research was carried out in 2018-2019 at 9 stations, three sites, three stations on each site. The dynamics of the average abundance and average biomass of phyto-zooplankton and zoobenthos over the study period is shown. The average indicators of the number and biomass of organisms are given and the main species are listed. During the study period, 73 species of microalgae belonging to 7 departments were identified in the phytoplankton: diatoms – 30 species, dinophytic – 23 species, green – 8 species, cyanobacteria – 5 species, haptophytic – 3 species, euglenic – 3 species, cryptophytic – 1 species. As part of the feeding zooplankton community, 17 species of organisms belonging to the following taxonomic groups were found: rotifers, oar-footed crustaceans, branched crustaceans, planktonic forms of shell crustaceans, larvae of small-lobed and multi-lobed worms; larvae of bivalves and gastropods. In single specimens, chironomid insect larvae and artemia eggs were found in the samples – juveniles of various-legged crustaceans, larvae and juveniles of worms, larvae of balanus. The dynamics of the average biomass and the average number of zoobenthos in three sections of the surveyed water area in the Kiziltash estuary during the study period is given. As part of the macrozoobenthos, 10 species were found in the surveyed water area, while gastropods and bivalves had the largest number of species. Gastropods dominated in numbers, and bivalve mollusks polychaetes dominated in biomass, crustaceans – barnacles and bokoplav and insect larvae were also found. The water area of the second section, located near the mouth of the Kuban River, was the most productive zone for phytoplankton, both in number and biomass, probably due to the increased content of organic substances. Coastal areas, less deep-water, are exposed to wind, therefore they have increased turbidity of water, which creates unfavorable conditions for the development of phytoplankton. Data on phytoplankton, zooplankton and zoobenthos obtained during the processing of hydrobiological samples of the Kiziltash estuary allowed us to conclude that the studied areas are suitable for growing oysters and mussels.