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Current issue: Volume 20, No. 2 (2020)
Paidere J., Brakovska A. 2020. Zooplankton community structure of the fish farm Nagļi
(Latvia). Acta Biol. Univ. Daugavp., 20 (2): 121 – 131.
Abstract
The community structure of zooplankton and its changes in lakes and ponds indicate the interaction of abiotic and biotic factors in them. In the fish farm Nagļi (Latvia) zooplankton community structure studies were based on the biotic parameters (predatory, competition) and analysis of the impact of environmental factors. Ponds studied are artificially created; located in one place, very shallow and take up a small area from ~ 0.80 ha to ~ 0.35 ha, are separated from one another, with one water supply and the water level is maintained by a flow. This study was conducted in May and July 2018, using appropriate standard methods for hydrobiological field and laboratory investigations. Although ponds are very similar, it was found out that the community structure of zooplankton differs both by taxonomic composition, abundance and biomass, in some ponds dominants are crustaceans (Cladocera, Copepoda), rotifers and copepods or only rotifers. The community structure of zooplankton indicates a predator, interspecies competition and “bottom up” control in fish ponds Nagļi (significant correlation between chlorophyll α concentration and rotifers biomass). In overall, ponds correspond to eutrophic waters either with clearer water or with turbid water state.
Key words: zooplankton, community structure, fish ponds, biotic abiotic interactions.
Jana Paidere, Aija Brakovska. Laboratory of Hydroecology, Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Parādes 1a, Latvia,
E-mail: jana.paidere@du.lv, aija.brakovska@inbox.lv
