Research
| Title: | Unintended outcomes of a long-term fishing ban on river macroinvertebrates |
|---|---|
| First author: | Li, Zhengfei; Liu, Fei; Garcia-Giron, Jorge; Zhao, Xianfu; Yang, Jiali; Xie, Zhicai; Zhang, Junqian |
| Journal: | REVIEWS IN FISH BIOLOGY AND FISHERIES |
| Years: | 2025 |
| DOI: | 10.1007/s11160-025-09985-0 |
| Abstract: | China's ten-year fishing ban (TYFB) in the Yangtze River represents one of the most extensive conservation initiatives ever implemented in the world's largest river basins. While the ban has facilitated the recovery of fish populations, its impacts on other ecologically vital but less conspicuous taxa, such as macroinvertebrates, remain largely unknown. Using a before-and-after comparison framework, we evaluated the responses of taxonomic, functional, and phylogenetic alpha and beta diversity of macroinvertebrates to the fishing moratorium in the Chishui River, an important tributary of the Yangtze River, after six years of TYFB implementation. We further assessed the relative influence of biotic (i.e., fish communities) and abiotic (i.e., environmental conditions) drivers on macroinvertebrate community composition across three fishing ban periods, and examined how the balance of ecological processes shaping community assembly shifted under the policy. Our results revealed that macroinvertebrate alpha diversity declined, whereas beta diversity increased following the TYFB. Interactions between fish and small-bodied macroinvertebrates consistently emerged as the dominant forces structuring macroinvertebrate communities, with the strength of these biotic associations intensifying over time. Moreover, the fishing ban progressively promoted a more stochastic organization of macroinvertebrate communities, likely driven by intensified predation pressure from recovering fish populations. Together, these findings provide novel insights into how human interventions can restructure community dynamics in natural ecosystems, highlighting the need to consider potential trophic cascade effects in long-term, large-scale conservation projects. Our study also challenges the notion that fishing bans invariably yields positive ecological outcomes. This awareness is particularly important as top predators are expected to expand ranges and increase populations through ongoing conservation efforts, which could potentially reshape predator-prey dynamics and ecosystem functioning worldwide. |
