Ecological assessment of eutrofication of lakes in «Shatskyі» biosphere reserve

Abstract

The natural process of eutrophication of hydroecosystems is determined by many factors and is mostly long-term, almost irreversible. In the 20th and 21st centuries. Accelerated anthropogenic eutrophication of many waters took place, in particular the lakes of Shatsky group (Shatskyi National Natural Park, Volyn Region, Ukraine). Changes in water due to their enrichment with biogenic substances and chemical compounds accompany the increase in plant productivity and may be the result of «natural aging», anthropogenic influence, organic pollution. One of the concepts of the succession of lake ecosystems assumes that lakes go through different stages of trophicity (nutrition), starting with oligotrophy or dystrophy. The last stage (climax) of the successional series is intensive eutrophication, during which the lake is partially replaced by a swamp and, in the end, can become a dry land, meadow, shrub or forest vegetation. Eutrophication of lake ecosystems is accompanied by a change in transparency, chlorophyll a concentration, and oxygen concentration. An active phase of eutrophication of the limnoecosystems of Shatskyi biosphere reserve has been established. On the territory of the latter there are rivers and streams with a constant water flow, more than 114 km long, and also includes 31 lakes. The results of ecological studies of various types of water bodies of Shatsky Lakes, which were carried out in 2016–2020, are presented. The performed typification of Shatsky Lakes by the area of the water mirror proved that there are no very large lakes here, there are three large lakes (Svityaz, Pulemetske, Luky-Peremut). The analysis of the nature-reserved territory of Western Polissia proved that special attention should be paid to lakes of small and small sizes, as well as medium and shallow lakes (Lynovets, Somynets, Buzhnya Bay, etc.), which are not capable of active self-regulation. The optimal mechanism for monitoring the ecological state of water bodies (lakes) using the remote sensing method is proposed.