Abstract
Investigations of the distribution of benthic macroinvertebrates in Lake Czarne were conducted in fall 2005 and spring 2006. Samples were taken in three transects (at a depth of 0.5 m and at 5 m intervals).
It was noted that macrobenthos only inhabit depths to 10 m. Laminar sediments from 15 m to 29 m indicate that macrobenthos never inhabit the deepest part of the lake in spite of temporary oxygen abundance (between 15 and 20 m during the winter and spring mixing periods). The largest diversity and biomass of macrozoobenthos was observed in the littoral zone at a depth of 0.5 m. At a depth of 5 m in the characean stands and at a depth of 10 m the number and biomass of benthic macroinvertebrates were significantly smaller. The reason for the decrease of benthos density seems to be gradual oxygen depletion.