Hydrology and Water Quality Shape Macroinvertebrate Patterns and Facilitate Non-Native Species Dispersals in an Inter-Basin Water Transfer System

Abstract

Understanding variations of aquatic community assembly under water diversions and other concurrent stressors is critical for aquatic ecological and environmental conservation, but hampered by limited research. Mechanisms of macroinvertebrate community assembly and maintaining were determined across five lakes along China’s South-to-North Water Diversion Project, an over 900-km water transfer system connecting four major Chinese river basins. We assessed patterns of macroinvertebrate assemblages from 59 sites in relation to attributes describing water quality, climate, spatial, and hydrologic factors based on multiple-analysis. Macroinvertebrate density, biomass, and species richness increased from upriver to downriver lakes, and were higher during the water transfer period than those in the non-water transfer period. Non-native species, such as Nephtys sp., Paranthura japonica , Potamillacf acuminata , Capitekkidae spp. and Novaculina chinensis were found along the entire study system, some of which have become dominant in upriver lakes. High turnover in beta diversity occurred in upriver Gaoyou and Hongze lakes. Hydrology and water quality are critical factors in shaping these macroinvertebrate patterns and facilitating the non-native species dispersal. This study has implications for lake management and ecological conservation under water diversions and other stressors.

Keywords: macroinvertebrate assemblages, water diversion, biological indicators, non-native species, water quality, hydrology