Macrozoobenthos in Mountain Standing Water Bodies in Bulgaria

A survey of macrozoobenthos in selected standing water bodies situated in mountain areas of Bulgaria was carried out. The study was conducted in the summer of 2020 (July-August) at one lake (Trevisto Lake - Rhodopes Mts.) and eight reservoirs (Ognyanovo - Sredna Gora Mts.; Bebresh, Hristo Smirnenski and Yovkovtsi (two sites) - Balkan Mts.; Belmeken - Rila Mts.; Batak, Golyam Beglik and Shiroka Polyana (two sites) - Rhodopes Mts.). These water bodies are classified as mountain type of water bodies according to the Bulgarian National Typology and are situated in two ecoregions, i.e. Ecoregion 7 (Eastern Balkans) and Ecoregion 12 (Pontic Province). Totally, 120 taxa have been identified. The macroinvertebrate communities were specific to lentic waters and were dominated by oligochaetes and chironomid larvae. Larvae of dragonflies, mayflies and caddisflies as well as aquatic beetles, freshwater gastropods and mussels were also present with great taxonomic diversity. The influence of the environmental factors on the formation of the macroinvertebrate communities in the studied lentic ecosystems was analysed.