Evaluating restoration success : ecosystem-level shifts in lake fish biodiversity consistent with China's fishing ban

2026

Article référencé dans le Web of Science WOS:001687277200001

Feng K., Tao K., Wang Y. D., Zhang Y. H., Deng L. W., Xu J. J., Feng W. T., Du X., Yuan J., Hugueny Bernard, Wang Q. D., Eros T.

Biological Conservation, 2026, 315, p. 111733 [11 p.] ISSN 0006-3207

Fishing bans are widely implemented to promote biodiversity conservation and ecosystem recovery, yet their ecological effects in lake systems remain poorly understood. We conducted a five-year, multi-lake assessment of China's Yangtze River Ten-Year Fishing Ban, one of the world's largest inland fishery closures, using standardized fish and water quality surveys in 24 shallow floodplain lakes before (2019) and mid-ban (2024). This before-after observational evaluation, combined with structural equation models, supports pathways linking fishing bans, nutrient dynamics, and fish community responses, but does not imply unequivocal causation. Analyses of taxonomic, functional, and phylogenetic diversity revealed that total fish abundance declined post-ban, local richness remained largely stable, and regional richness were heterogeneous, reflecting reduced community size that limits detectability of rare or habitat-specific species. Community evenness increased in many lakes, dominance of eutrophication-adapted functional groups declined, and between-lake beta diversity rose, suggesting greater inter-lake heterogeneity. Phosphorus-related eutrophication metrics improved, whereas nitrogen levels showed no consistent change. These patterns reflect ecosystem reorganization and trade-offs: reductions in harvest and aquaculture nutrient subsidies led to lower productivity/biomass, while community restructuring shifted dominance, evenness, and beta diversity. Lake-specific factors, including area, shoreline complexity, and historical fishing intensity, moderated ecological responses, highlighting context-dependent recovery trajectories. Early-stage recovery may not manifest as higher richness or biomass, but as shifts in community composition, functional dominance, and nutrient dynamics. System-level success can be summarized as simultaneous improvements in water quality, a more balanced distribution of functional groups, and increased differentiation among lakes, even when total fish biomass declines.

Ecologie, systèmes aquatiques [036] ; Ressources halieutiques [040] ; Etudes, transformation, conservation du milieu naturel [082]

CHINE ; YANGTZE COURS D'EAU

Fonds IRD [F B010096349]

fdi:010096349