̉he present study was focused on the influence of heterogeneity of the bottom substrate and the amount of organic carbon in sediments on the riverine macrozoobentos trophic structure. The benthic and sediment samples were taken in the spring and autumn of 2011 and 2012 from four Bulgarian rivers – Mesta, Vit, Tundzha and Veleka, situated at three different water catchment and basin districts.
RDA analysis demonstrated relationships between the different types of substrate and distribution of the functional feeding groups (shredders and scrapers with stones, predators with gravel, filterers and deposit feeders with aquatic vegetation and muddy river bed, collectors with sandy substrate). Proportional dependence between organic carbon in the bottom sediments and the deposit feeders group was established.
Key words: river sediments, benthic macroinvertebrates, deposit feeders
Topic: BIOLOGY