Zooplankton Community Metrics as Indicators of Eutrophication in Urban Lakes

Although the direct effects of eutrophication are well known, its indirect effects are poorly understood and the interaction with non-nutrient factors may alter some expected relationships. We analyzed the reliability of community-level metrics derived from three zooplankton groups as predictors of eutrophication in urban man-made lakes. Univariate and multivariate correlation analyses were used to test for relationships between environmental variables and community metrics derived from zooplankton data. Our results indicated that rotifer community metrics were the best eutrophication indicators. The main implication of our results is that arguments against the use of simple community-level metrics as indicators of eutrophication cannot be generalized. Our findings also suggest the need of complete sample analyses (i.e., identification and counting) to estimate reliable ecological indicators of eutrophication.