Diversity and variability of phytobenthos in the western coastal area of the Crimean peninsula
Based on the original data of the summer hydrobotanical survey (2020), an inventory of the taxonomic composition of macrophytobenthos in three key sites (Yazykovaya Balka, Cape Margopulo, and Nemetskaya Balka) of the western coast of the Crimean Peninsula was made for the first time. We found 61 species of macroalgae of the departments Chlorophyta, Ochrophyta, and Rhodophyta in the benthic flora. Considering the species composition in the near by area of the «Coastal aquatic complex at Cape Lucull», the phytobenthos along the western coast of Crimea consists of 74 species. Taxonomic analysis has established the dominance of red algae and allowed to allocate taxons with high species and genus diversity. Ecological analysis showed the predominance of the leading, annual, oligosaprobic and marine groups, uniting from 45 to 72% of species. The divisions differed in the degree of completeness of the ecospecies and in the dominant ecogroups. Among the divisions,Ochrophyta is characterized by a pronounced homogeneity of ecological composition. The level of development of mesosaprobic group (indicator of organic pollution of the marine environment) is consistent with the Cheney index value (3.4) and indicates an average degree of habitat pollution in the study area. High similarity of species composition of phytocenosis, Ochrophyta and Rhodophyta is typical for algae of Nemetskaya Balka and Cape Margopulo. In Chlorophyta, species differences are minimal in the area of Yazykovaya Balka and Cape Margopulo. The mean value of Jaccard's coefficient is higher in Chlorophyta and Rhodophyta than in Ochrophyta. The taxonomic composition of phytocenosis at the threesites on the western coast of Crimea is characterized by a combination of quantitative stability and qualitative variability in space. The spatial variability in the number of species in ecogroups does not exceed the«norm», corresponding to its lower - normal subtype. A comparative analysis showed the absence of significant differences in the composition of phytobenthos in the protected water area of the nature monument and outside its boundaries, which is primarily determined by the similarity of habitat conditions, rather than by the effectiveness of conservation measures.