Abstract: Shahu Lake, Mingcui Lake, and Liuxi Lake, which are typical inland shallow lakes in the Yinchuan Plain, are polluted by endogenous contaminants. Since 2015, dredging projects have been implemented to manage endogenous pollution, which has improved the ecological health of the lakes. To investigate the response of macroinvertebrates in inland lakes in Yinchuan Plain to the dredging project, a total of 16 sampling sites were set up for field surveys in 2015 (before dredging) and 2020 (after dredging) in the three lakes. The results showed that the average density and biomass of macroinvertebrates in Shahu Lake were lower after dredging than those before dredging, while the average density and biomass in Mingcui Lake and Liuxi Lake were higher after dredging than those before dredging. The dominant species and feeding functional groups of macroinvertebrates changed greatly after dredging. Non-metric multidimensional scaling (nMDS) results showed significant differences in macroinvertebrate community structure before and after dredging. The indicator species analysis showed structural changes in the macroinvertebrate community before and after dredging. Results of beta diversity partitioning showed that the beta diversity of macroinvertebrates was largely contributed by species turnover both before and after dredging. The dredging projects increased beta diversity and the contribution rate of species turnover to the beta diversity. Our results clarified the characteristics of the macroinvertebrate community of inland lakes in response to dredging, and provided a basis for ecological management and biodiversity conservation of urban shallow lakes.

Key words: macroinvertebrate, species diversity, species turnover, dredging, urban shallow lake