The Ecological Study Of Macrobenthos In The Qingcaosha Reservoir

Shanghai Qingcaosha Reservoir is an important strategic water sources, and is also the drinking water source protection areas, Qingcaosha Reservoir water quality will be directly related to the Shanghai Urban water supply security, it is essential to maintain the water clean and safe. By ecology of macrobenthos community structure Qingcaosha Reservoir,we not only can grasp Qingcaosha Reservoir macrobenthos species composition, structural characteristics of biomass, bio-diversity, community stability, and evaluate Qingcaosha Reservoir water quality from the ecological perspective. We conducted Qingcaosha Reservoir macrobenthos monthly surveys from 2014 to 2015, the main results were as follows:1、According with the g Qingcaosha Reservoir hydrology,we set up a total of 11 sites. It was found during the investigation macrobenthos 26 species by the polychaetes、oligochaeta、crustaceans and chironomid larvae components. To determine the dominant species of Qingcaosha Reservoir macrobenthos by IRI value, the result showed that: During the investigation no significant changes in dominant species, are Dentinephtys glabra, Goniada japonica and Corophium volutator.2、Macrobenthos annual abundance was 129.78±40.66 ind·m^-2, with average annual biomass was 0.54 ± 0.22 g · m^-2. Abundance showed autumn> spring> winter> summer,biomass was winter> autumn> summer> spring, abundance and biomass of reservoirs were both highly in the midstream reaches,low abundance was in the upstream reaches, low biomass was in the downstream reaches. Two-way ANOVA showed no significant differences in the abundance and biomass.3、Macrobenthos community similarity index of 2014 and 2015 was 0.69, two communities was in the middle of similarity, community structure was in successional stages. Community Clustering and MDS analysis showed that the macrobenthos community roughly could be divided into five categories, namely S1, S10, S11 as a type; S2, S3, S4 as a type; S8, S9 as a type; S5 as a type; S6, S7 as a type. Temperature, dissolved oxygen, transparency was the significant environment factor of macrobenthos community composition by RDA analysis. Two-way ANOVA showed that macrobenthos biodiversity index H ’, J and D was no significant difference between each sampling area and sampling time, using the biological diversity index to judge water quality was deviational, and did not complied with the poor nutritional status of the reservoir, so the study did not use this method. 4、Carlander biomass index shows that Qingcaosha Reservoir water was in poor nutrition from 2014 to 2015. During the investigation,the mainly pollution indicator species were Oligochaeta and chironomid larvae,and mostly was light pollution indicator species. In this study, biological Pollution Index（BPI）, Goodnight modified index（GBI） and Hilsenhoff Biotic Index（BI） were used to evaluate Qingcaosha Reservoir water quality, the results showed that the reservoir was in light pollution.5 、 According to the analyzing of Qingcaosha Reservoir abundance-biomass curve（ABC curve）in different sampling seasons and regions from 2014 to 2015,we can judge macrobenthos community and water pollution. The results showed that: Abundance-Biomass curves appeared a varying degrees of cross、overlap,which means the stability of benthic community structure decreased, the community structure disturbed by water pollution,and water pollution was in a certain degree. The number of various groups appears to fluctuate, the individual smaller pollution indicator species began to increase. It also shows that the macrobenthos community in the reservoir is still in the stage of succession.