Современное состояние рек бассейна озера Сегозеро (Сегозерское водохранилище, Республика Карелия)

Abstract

The chemical features and the structure of biological communities in the in the three watercourses of Segozero Lake basin. Analysis for the species composition, abundance and biomass of phytoperiphyton, zooplankton, and zoobenthos was carried out. The effect of natural and anthropogenic factors on the formation of the chemical features and structure of lake hydrobiocenoses was analyzed. Variations in the structure of aquatic organism communities are due primarily to specific hydrographic and hydrological characteristics of river stretches. The paper is discussed the main principles of the changes in a structure and functioning of hydrobiont communities in rivers. The trophic status of the rivers, their saprobiological slate, and the significance of individual communities and biotic indices for bioindication of the ecological state of the rivers, are estimated. We concluded that consideration of three groups of organisms enables more comprehensive and reliable monitoring than assessment based on a single group. The abundance and biomass of phytoplankton, phytoperiphyton, zooplankton, and zoobenthos suggest the relatively high degree of their development in lake water, as well as their activity and stability. A peculiarity of the structure of hydrobiocenoses is that they consist of species with appreciably different sizes: from several microns to several centimeters. Therefore, the lists of species dominating in terms of abundance and biomass differ appreciably.