大渡河安谷水电站施工期春、秋季浮游动物群落特征分析

Spring and Autumn Zooplankton Community Characteristics during Construction of Angu Hydropower Station on Dadu River

研究安谷水电站施工期浮游动物对水文情势改变、栖息地条件变化等工程影响的响应,为径流式水电工程建设对浮游动物的影响预测评价提供参考,为安谷水电站水生态环境发展或生态修复提供科学依据。2014年春季、秋季对大渡河安谷水电站施工期浮游动物及水环境因子进行调查采样,利用SPSS和Canoco软件进行数据分析。结果表明:大渡河安谷水电站施工期春、秋季共检出浮游动物69属116种,密度平均为619.65个/L、生物量平均0.093 mg/L。左侧河网浮游动物种类、密度和生物量高于干流。浮游动物种类、密度、生物量和多样性指数在季节分布上差异显著,春季明显高于秋季。浮游动物种类、密度、生物量与环境因子硝氮、总氮、磷酸盐、总磷呈显著正相关,与流速呈负相关;RDA结果进一步说明硝氮、磷酸盐、TN、TP是影响浮游动物群落结构的重要环境因子。

Zooplankton is extremely sensitive to environmental change.In this study,we investigated the dynamics of zooplankton community structure before and during construction of Angu hydropower station on Dadu River and analyzed the response of the zooplankton community to changes in hydrological regime and habitat status over the construction period.The aim of the study was to provide a reference for predicting the effects of constructing run-off hydropower projects on zooplankton and data to support ecological restoration of habitat impacted by the Angu hydropower project.In May(spring)and October(autumn)of 2014,zooplankton was investigated at eight sampling sites during the construction period of Angu hydropower station,focusing on species composition,density,biomass and community diversity indices.Water environment factors were determined simultaneously.A total of 116 zooplankton species from 69 genera were detected in spring and autumn.The average density and biomass of the zooplankton community were 619.65 ind/L and 0.093 mg/L.The number of species,density and biomass of the zooplanktons in left bank tributaries were higher than in the main stem.There were significant seasonal differences in species composition,density,biomass and diversity indices of the zooplankton community,all higher in spring than in autumn.There were significant positive correlations of species number,density and biomass with nitrate nitrogen,TN,phosphate and TP,and significant negative correlations with flow.Redundancy analysis(RDA)indicated that nitrate nitrogen,phosphate,TN and TP were the important environmental factors affecting zooplankton community structure.Hydropower construction projects bring tremendous economic and social benefits,but negatively impacts the surrounding aquatic environment.Our results show that zooplankton density and biomass decreased as a result of constructing the hydropower station and other human interference.Therefore,environmental protection measures should be carried out to reduce the impacts of hydropower station construction and operation on aquatic organisms and promote harmony between humans and the water environment.