New Data on Bottom Invertebrates of the Negovan Marshes and the Adjacent Lesnovska River

The current study presents recent data of the benthic macroinvertebrate fauna of two pit lakes (the Big Lake and the Small Lake) and the adjacent sector of the Lesnovska River near Negovan Village, western suburb area of the capital city of Sofia, western Bulgaria. The two pit lakes are under different degree of degradation. The Big Lake is still used for excavation of inert materials, while the Small Lake has been abandoned years ago and has slowly restored its quality of a natural wetland. Both lakes have never been studied hydrobiologically apart from several faunistic contributions. In the present study, parameters, indices and metrics indicating the cenotic structure of the benthic community and ecological state of the water bodies were used following the national regulations. The macrozoobenthos density in the Big Lake was lower in comparison to the Small Lake and the Lesnovska River. The river and the Small Lake had high level of faunistic similarity. Some non-indigenous and invasive species were registered in both lakes.