The effect of wind speed decline on macroinvertebrates in Lake Taihu, China

A decline in wind speed will have a series of effects on a lake ecosystem. Attention should be paid to macroinvertebrates, a critical ecosystem component, but few previous studies have considered these organisms. To study the influence of wind speed on macroinvertebrates, we selected Meiliang Bay and Zhushan Bay in Lake Taihu, which have high spatial homogeneity. The response of the benthic community and dominant species to a decrease in wind speed was studied using eight years of field survey data through NMDS analysis and regression analysis. The results showed that the decrease in wind speed significantly changed the structure of the macroinvertebrate community. Wind speed may affect macroinvertebrates directly or indirectly, mainly through wind-wave disturbance or changes in dissolved oxygen and food resources. The responses of different species and different growth stages to wind speed varied. According to the regression results, among the 8 most dominant species, the abundance of chironomids and malacostracans was positively correlated with wind speed, and that of bivalves and some oligochaetes was negatively correlated with wind speed. However, while the abundance of oligochaetes was negatively correlated with wind speed during the larval period, it was positively correlated with wind speed during the adult period. With future declines in wind speed, corresponding changes in the dominant species in Lake Taihu will have a series of effects on lake ecosystem, and more attention should be paid to these processes in future studies.