Effects of Carp (Cyprinus Carpio) and Bream (Abramis brama) on the Structure of Littoral Communities in a Mesotrophic Lake: Mesocosm Experiments
V. P. SEMENCHENKO, M. D. MOROZ, E. A. SYSOVA, T. P. LIPINSKAYA
Scientific and Practical Centre for Bioresources, Nationаl Academy of Sciences, 220072, Minsk, Akademicheskaya str., 27
Keywords: карп, лещ, фитопланктон, зоопланктон, макрозообентос, carp, bream, phytoplankton, zooplankton, macrozoobenthos
Abstract
In order to compare the impact of alien common carp ( Cyprinus carpio ) and native bream ( Abramis brama ) on water chemistry, phyto- and zooplankton, and macrozoobenthos, nine enclosures, 9 м2 each, were placed in the littoral zone of Lake Obsterno (Republic of Belarus) at a distance of 60 m from the shore. Feeding behavior of carp, characterized by extensive burrowing in the sediment, led to the change in the phytoplankton community structure. But the significant differences in algae biomass between control and fish enclosures were received only for diatoms algae. Carp had a more pronounced effect on abundance of large-bodied species of zooplankton ( Diaphanosoma brachyurum ) than bream did. For both fish species an increase in abundance of small-bodied Bosminа longirostris was recorded. Decreased abundance and biomass of macrozoobenthos occurred at a much higher rate within the carp enclosures, with the strongest impact on ephemeropterans. There was no difference in the consumption of chironomids and oligochaetes regardless of fish species.
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