Macroinvertebrate community composition and river health assessment in plateau rivers of Guizhou Province, China

ABSTRACT: Plateau rivers are considered regional water resource depots, hydropower energy bases, cradles of aquatic dispersal, and barriers to invasive alien species. In this study, 20 major plateau rivers from Guizhou Province, China, were studied to (1) investigate the composition, functional feeding group distribution, and diversity of macroinvertebrates; and (2) assess the ecosystem health of the rivers using the macroinvertebrate Family Biotic Index. Among the macroinvertebrate species, the dammed river sections primarily contained Corbicula fluminea and C. nitens from the Lamellibranchia, the urban river sections harbored Bellamya aeruginosa and Semisulcospira cancellata from the Gastropoda, and the reference river sections contained sensitive taxa including mayfly Ecdyonurus yoshidae and caddisfly Stenopsyche tlenmushanensis. Among the major plateau rivers in Guizhou, urban river sections exhibited the highest density of macrobenthic organisms. The Shannon-Wiener index was lowest in dammed sections, followed by urban sections, while reference sections exhibited the highest diversity. As for functional feeding groups, the density of filter feeders was significantly higher than that of other groups. In contrast, the density of gatherer-collectors and the shredders was relatively low. Assessment of the aquatic ecosystem health in Guizhou Plateau rivers showed that dammed sections were primarily in an unhealthy state, urban sections mainly fell into the sub-healthy category, and reference sections had a relatively good health status. The results from this study provide baseline data that is useful for water resources management, hydropower energy utilization, and ecological and environmental protection of the plateau rivers.