Impacts of small hydropower plants on macroinvertebrate communities

The influence of small hydropower plants (SHPs) on the spatial distribution of macroinvertebrate assemblages was investigated in 5 cascade SHPs along the Xiangxi River in October 2005. 5 sites were sampled at each SHP. A total of 4656 macroinvertebrates belonging to 69 genera were collected. The characteristics of macroinvertebrate community structures were analyzed by using richness, abundance, dominant species and functional feeding groups. The results suggested that construction of SHPs had no significant impact on water chemistry, but on physical variables (such as current velocity and water depth) which varied significantly among the 5 sites. All the characteristics of the macroinvertebrate community were more or less affected by the construction, especially by the abundance, filter-collector percentage, predator percentage, and the stations. The results also suggested that the sites beneath the dam had the most different community structures, indicating that diverting the water current completely is harmful to the protection of macroinvertebrate diversity of the river.