Ecotoxicological Evaluation of the Recommended Values of Nutrient Criteria for Lakes in East-central China

Based on the candidate values of nutrient criteria inferred by structural equation modeling (SEM) and reference conditions values from other references, the experiment established three recommended values of nutrient criteria for lakes in East-central China, and ecotoxicological evaluation was carried out for the lakes in East-central China with Daphnia magna in order to get reasonable nutrient criteria values. Meanwhile, the effects of total phosphorus, total nitrogen, chlorophyll-a and pH on Daphnia magna growth and reproduction were explored. According to the observation and comparison of growth and reproduction of Daphnia magna, the values of nutrient criteria for the lakes in East-central China were obtained as follows: TP of 0.036 mg/L, TN of 0.72 mg/L and Chl-a of 3.6 mg/m³.