New data on zooplankton communities of two Bulgarian reservoirs: Konush and Sinyata Reka, Plovdiv Region

Abstract

Zooplankton communities have several vital functions within lake ecosystems, including the transfer of energy and material from producers to secondary consumers. Their structure is potentially affected by both lake morphology and typology, as well as by anthropogenic changes in lakes. These communities are also sensitive to various substances in the water column, e.g. nutrients and pollutants. Thus, they have often been used as indicators to assess the condition of and changes in lentic environments. Our aim was to present first detailed data about the species composition and structure of zooplankton communities in two understudied Bulgarian reservoirs, the Konush and Sinyata Reka Reservoirs. Twelve samples were collected in spring and summer 2016. The qualitative analysis of the zooplankton revealed the presence of 40 taxa from three main taxonomic groups: Rotifera, Cladocera and Copepoda. From these, the most frequently occurring were the rotifers (53.66%), followed by the cladocerans (24.39%) and the copepods (21.95%). The established high abundance and higher species diversity of rotifers, together with the equal distribution for all zooplankton species in the samples, confirmed the eutrophic status of both reservoirs.

Keywords

• zooplankton
• diversity
• eutrophic reservoirs
• Ecoregion 7
• Bulgaria