Trophic Structure of Macrozoobenthos and Assessment of Ecological Status of Lakes and Reservoirs in Bulgaria

摘要

The trophic structure of macrozoobenthos in 50 of the largest standing water bodies (lakes and reservoirs) in Bulgaria was studied. Two-year benthic sampling from 11 lakes and 39 reservoirs, belonging to 15 national types of standing water bodies were taken. The analysis of the taxonomic composition and the abundance of functional feeding groups showed that the groups of scrapers and deposit feeders dominated in the trophic structure of the macrozoobenthos. The scrappers had a structuring role in lakes and the deposit feeders prevailed in modified/artificial standing waters (reservoirs). Ecological status assessment of the studied water bodies based on the metrics Total number of taxa, Biotic index for slow-flowing stretches and Trophic index, was made. The assessment based on the macrozoobenthos reveals that the prevailing part of the studied reservoirs was defined in the range from "High" to "Moderate" ecological status or potential.