Abstract: An acute toxicity test was conducted to assess the toxicity of an industrial wastewater to Moina macrocopa. The 24 h and 48 h semi-lethal (LC50) for M. macrocopa were 1768% and 1456%, respectively, indicating that the industrial wastewater was very toxic. Based on the LC50, six concentrations (0, 1%, 2%, 4%, 8% and 16%) of the industrial wastewater were installed to study their effects on the heart rate, body length, and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) of M. macrocopa. The results showed that with increasing concentration of wastewater and with increasing time, the heart rate and body length of M. macrocopa increased first and decreased then; while the activities of GST, CAT and SOD had a trend of increasing at low concentration wastewater but decreasing at high concentration wastewater. When exposed to the wastewater, SOD activity had a larger variation than GST and CAT activities, suggesting that SOD could be an important enzyme for organisms to resist bad environment, and a sensitive bio-indicator for wastewater monitoring.

Key words: Fisheries resources, Sustainable use, Grey relative relationship, Zhoushan fishing ground, Indicator system