Limnological study of Serbian oxbow shaped Lake Srebrno, with special emphasis on the benthic community composition and structure

Detailed limnological study of the Lake Srebrno (Serbia) bottom fauna was performed in March 2007. Investigations included qualitative, quantitative, and saprobiological analysis of bottom fauna communities, physical and chemical analysis of sediments and determination of chlorophyll a concentration, as well as saprobic and trophic status analyses. Samples were collected at eighteen sites distributed along a shoreline and in deeper sections of the lake. Twenty taxa from nine macroinvertebrate groups were recorded. Family Chironomidae had the biggest index of participation, the highest species diversity and the largest density of populations in benthocenoses of Lake Srebrno. Faunistic similarity between sites was estimated according to Sorensen’s Quotient of Similarity (QS). The majority of benthocenoses - 56% showed a medium level of faunistic similarity (QS = 21-60%), and 42% of benthocenoses showed a high level of faunistic similarity (QS = 61-100%). The classification of Lake Srebrno based on saprobic and trophic levels was assessed. Saprobic level was in the range from alpha-meso- to poly-alpha-mesosaprobity. The water quality of the lake ranged from class III and between IV and III class. Generally, Lake Srebrno had eutrophic status with the gradation to hypertrophy.