Unraveling the nexus of multi-environmental factors and benthic macroinvertebrates in typical inflow river of Taihu Lake in China.

The objective of this study is to examine the relationship between benthic macroinvertebrates and various environmental factors (i.e., physicochemical properties of sediment and hydromorphological condition) in the typical inflow river sediments of the Taihu Basin in China. Pearson correlation and redundancy analysis (RDA) were used to investigate associations between environmental factors and benthic macroinvertebrate community structure. The RDA results indicated that the environmental factors account for 58.6% of the spatial differentiation of benthic macroinvertebrate community. High density of Oligochaeta species, which were potential indicators of heavy metal pollution within sediments, was observed as the pollution-tolerant species in the study area, indicating that the benthic community was seriously polluted by heavy metals and nutrients. Moreover, the variation in benthic macroinvertebrate community structure and trait composition were mainly explained by physicochemical properties of sediment (e.g., Pb, temperature, and phosphate), whereas hydrological condition (e.g., turbidity) alterations played a less important role. Thus, the environmental factors are significantly correlated with the abundance and biomass of benthic macroinvertebrate by taking interacts of multi-environmental factors into account. These results provide scientific basis for water environment health management and pollution control in Taihu Basin river network area.