STRUCTURE OF MACROBENTHOS OF THE WHITE SE A LITTORAL WITH A STRONGLY PRONOUNCED GRADIENT OF ENVIRONMENTAL-FACTORS

Directional change in community structure along the estuary was shown by different statistical methods (cluster and gradient analyses). The gradient is unequal along the shoreline, and the changes increase with the decrease of the maregraphic level. The pronounced and stable spat ial structuring is not accompanied by apparent species differentiation . Principle component analysis revealed two major factors of environme ntal variability determining macrobenthos community structure. The fir st component is a combination of the salinity conditions and the mareg raphic level; the second one corresponds to portions of the pelite fra ction of the bottom sediments and the biomass of the macrophytes.