RESERVOIR-RIVER RELATIONSHIPS IN LOWLAND, SHALLOW, EUTROPHIC SYSTEMS: AN IMPACT OF ZOOPLANKTON FROM HYPERTROPHIC RESERVOIR ON RIVER ZOOPLANKTON

摘要

An aim of the research was to test a hypothesis that impact of a shallow hypertrophic reservoir on riverine zooplankton is limited to a short section of the outflowing river because of a rapid conversion of the lentic habitat into the lotic one. The second hypothesis assumed that species richness of zooplankton is increasing along the river due to washing out littoral and benthic species. The study was carried out in the years 2009-2010, during summer-autumn strong dominance of toxic filamentous Cyanobacteria in a shallow hypertrophic humic Siemianowka Dam Reservoir (northeast Poland) and the outflowing Narew River. During research samples were collected on three consecutive days because water requires approximately as much time to cover the distance from the dam down to 118 km of the river.