Influence of Different Types of Small Hydropower Stations on Macroinvertebrate Communities in the Changjiang River Basin, China

Abstract

Many studies have investigated the influence of hydropower stations on macroinvertebrate communities, but few have clarified the influence of different types of hydropower stations. A total of 133 samples obtained from seven rivers, on which 45 hydropower stations are located, with the rivers distributed across four provinces (Yunnan, Jiangxi, Fujian, and Hubei) were investigated to study the influence of different types of small hydropower stations on macroinvertebrate communities. Samples were collected during 2011−2012. Results showed that 126 taxa of macroinvertebrates were collected, of which 68.3% were insects. The average macroinvertebrate density and biomass were 966 ± 112 ind/m2 and 17.31 ± 1.54 g/m2, respectively. For dam-type hydropower stations, the intercepting effect of the dam was the main factor affecting macroinvertebrate populations, whereas the influence of hydrological period was nonsignificant. Macroinvertebrate taxa richness exhibited a gradual increase from reservoir reaches to down-dam reaches and then to natural reaches (4.4, 6.5, and 9.5, respectively). The Shannon−Wiener index showed a similar increasing trend (1.06, 1.48, and 1.58, respectively), whereas biomass levels exhibited a decreasing trend (56.3, 25.2, and 6.0 g/m2, respectively). For the diversion-type hydropower stations, hydrological period was the main influential factor, whereas the intercepting effect of the dam was nonsignificant. From wet to dry seasons, increases were observed in macroinvertebrate abundance (5.2 to 8.3), density (322.2 to 1170.5 ind/m2), biomass (24.6 to 40.1 g/m2), and Shannon−Wiener index (1.23 to 2.08).

Keywords

• small hydropower station
• dam-type hydropower stations
• diversion-type hydropower stations
• macroinvertebrate communities
• Changjiang River Basin