Assessment of pollution status of Dalianhu water sources in Shanghai, China and its pollution biological characteristics

The present study was undertaken aiming to assess the water quality state of different parts (i.e. external river, aquaculture ponds, lake area, water forests, internal river and swampland) of Dalianhu water sources in Shanghai (China), by investigating the community structure characteristics of zooplankton and benthos along with some water quality parameters (TN, TP, COD, etc.). Some diversity indices were calculated, including Shannon–Wiener index (H) for both zooplankton and benthos, Margalef’s diversity index (D) for zooplankton and Goodnight modified index (G) and Biological pollution index (BPI) for benthos. The obtained results shows that in Dalianhu water sources, the Shannon–Wiener index of zooplankton (H _z) is 0.3–1.83, the Margalef’s diversity index of zooplankton (D) is 1.0–10.4. The Shannon–Wiener index of benthos (H _b) is 0.81–1.26, the Goodnight modified index of benthos (G) is 0.30–0.88, the Biological pollution index (BPI) is 1.1. These findings determine the water quality in Dalianhu water sources which belong to the moderate pollution. By comprehensive analysis together with zooplankton, benthos indices and water physicochemical parameters, the pollution level of Dalianhu water sources is in turn water forest, inner river, aquaculture ponds, external river and lake area, showing that the pollution of the Dalianhu water sources is mainly internal. It was suggested that the further work departments should be carried out to strengthen the necessary consolidate management and ecological repair.