Characterizing Spatio-Temporal Variation in Macroinvertebrate Communities and Ecological Health Assessment in the Poyang Lake Basin During the Early Stage of a Fishing Ban.

Macroinvertebrates are a crucial part of aquatic ecosystems and significantly contribute to the maintenance of their health and stability. Our aims were to explore spatio-temporal patterns in macroinvertebrate communities and evaluate the ecological health of various parts of the Poyang Lake Basin during the early stage of a fishing ban. We collected samples using a Peterson grab sampler and conducted ecological evaluations using the B-IBI index. A total of 107 species of macroinvertebrates were identified, and most species were arthropods. The density and biomass of macroinvertebrates significantly differed among seasons and water bodies. No significant differences in diversity among seasons were observed; however, diversity significantly varied among water bodies. Environmental parameters such as water depth, pH, turbidity, total nitrogen, total phosphorus, and chlorophyll a played a crucial role in shaping the community structure of macroinvertebrates. Most of the sampling sites were classified as healthy or sub-healthy, indicating that the fishing ban policy has started to have a positive effect. The effects of this ban are achieved through a cascading sequence of processes, including the elimination of fishing disturbance, the restoration of habitat structure, and the reallocation of trophic energy, in addition to increases in microhabitat diversity associated with habitat heterogeneity. Together, these processes drive the multidimensional recovery of macroinvertebrate communities, manifested as increased species richness, higher density and biomass, and elevated B-IBI scores.