Identifying relations between ecological integrity and environmental stressor information in Tai Lake of China: Towards the development of ecological criteria

The integrated index values of ecological criteria of Tai Lake in China were calculated based on the variety of plankton communities in the waters and external environmental stresses. Considering the guideline for biological criteria issued by the U.S. Environmental Protection Agency (USEPA) and combining the physical and chemical factors, the primary framework for developing ecological criteria was provided The framework includes 4 steps: ① Determined the reference sites and watershed ecological characteristics ② Drew box plots for reference sites and scoring ③Added the scores of ecological criteria indices by equal weight and set 90 quantile as the value of Index of Ecological Integrity(IEI) ④identifying IEI, DO and Chl a relations to developing ecological criteria. The values of DO ecocriteria of Tai Lake were 10.37 (2009 summer) and 10.30 (2010 summer). The values of Chl a ecocriteria were 4.61(2009 summer) and 4.53 (2010 summer). The winter data is not suitable for the calculation of ecocriteria. Basically, the method based on the variety of plankton communities is feasible to calculate the values of ecological criteria.