Hydro-botanical studies of the protected water area of the Western Crimea (Black Sea)

Crimea is the world center of wild plant diversity. Objects of the reserve fund are located along its banks. With an increase in anthropogenic impact on protected marine objects, their biodiversity is decreasing. There is a need to make forecasts of the impact on the coastal zone. Forecasts should be based on the results of long-term observations. In the water area of the natural monument «Coastal Aquatic Complex at Cape Lucull», such observations were carried out sporadically in the middle of the twentieth century. Information on the floristic composition of the site is scarce. The aim of the work was to study the composition, structure, occurrence of species and spatial variability of the macroflora collected from three sites of the monument. Hydrobotanical research was carried out in the summer of 2020. Samples were taken by a diver on three transects at a depth of 0.5, 1, 3, 5 and 10 m. A list of 61 species of Chlorophyta, Ochrophyta, Rhodophyta has been compiled. A quarter of the species have a conservation status. The flora is based on a limited number of supraspecific taxa. The taxonomic structure of Ochrophyta is the most simplified. The constant core of the flora includes 44% of the species. The maximum of most taxonomic parameters of phytobenthos is associated with Cape Vai-Vai, and the minimum with Cape Tyubek. After half a century, the species diversity of Chlorophyta has increased, Rhodophyta and phytocene has decreased. The ecological transformation of the phytocene is accompanied by an increase in the species richness of the Chlorophyta and Rhodophyta ecogroups, especially the mesosaprobic and brackish-water-marine ones. Chlorophyta was replenished with brackish and polysaprobic species; in Ochrophyta, the diversity of the marine, short-growing and oligosaprobic groups decreased, which indicated the deterioration of the ecological situation in the studied area. Based on the studies carried out, a list of species was compiled, the level of taxonomic diversity and parameters of spatial variability of the community of the protected water area were determined.