Kulakova I. Features of Distribution of Freeliving Nematodes in the Northwestern Black Sea

Free-living nematodes in the northwestern Black Sea. The study of thetaxonomic composition, characteristics of their distribution and theinfluence of some abiotic factors on the development of free-livingnematodes in the northwestern part of the Black Sea where they were notstudied earlier. During all the years, monthly samples were taken at one and the same time. A metal suction tube of 28 mm diameter opening (modification Vorobyova, 1977) was used for sampling. Samples were taken from two layers in the pseudolittoral, and from 5-6 in the sublittoral. For meiobenthos samples, in the latter, the Petersen grab ''Okean" was used. For analysis, the density index of separate species - №PB was used as well as the frequency factor and Shannon-Weaver dominance index (1963). For the study of the species structure of nematode communities, curves of dominance and biodiversity were used (Odum, 1986). Scientific results of the author differ from existing in that data have been obtained for biological diversity andquantitative evaluation of free-living nematodes. Also the laws governing the formation of nematode communities in the northwestern Black Sea in eutrophic conditions have been described. It has been shown that together with other meiobenthos representatives, nematodes being quick to react to changes in the environment may be used for assessment of ecological processes taking place in the given area and prognosis of consequence. The data and recommendations of the author on the possibility of using certain nematode parameters for assessing and predicting the ecological state of the marine environment have been used manyfold for performing several projects and themes, and also for preparing expert conclusions for ecological substantiation (NAMIT, Black Sea, Biological Resources, Copernicus, some EIA). Hydrobiology, zoology, ecology, aquatic toxicology.