The plankton assemblages as potential bioindicators in the environmental conditions of Danube Delta

The influence of physicochemical parameters other than the nutrients load on the community structure of phyto- and zooplankton in lowland shallow lakes is still poorly understood. In this study we investigated the structure of the plankton community in Danube Delta (Romania) and the relationships with environmental variables. Among the 206 taxa observed, 33 species were dominant. Canonical Correspondence Analysis indicated that incident light, lakes depth, surface area and water conductivity were of significant importance in controlling the variation in the structure of the plankton assemblages. The resulted models from averaging regression and cross-calibration predicted the main environmental parameters and allowed the selection of phyto and zooplankton species as potential biological indicators. Weighted averaging regression and cross-calibration generated useful models for predicting the main four investigated environmental parameters, which contribute to the selection of phyto- and zooplankton species as potential biological indicators.