Data from: Direct and indirect effects of a fishing ban on lacustrine fish community do not result in a full recovery

Protected areas are increasingly being promoted as an important means of
protecting freshwater biological diversity and ecological processes. A
robust assessment of ecological changes in protected areas is fundamental
to optimize conservation policies and adaptive management. China's
efforts to establish aquatic reserves have attracted worldwide attention,
especially the "10-year fishing ban" implemented in the Yangtze
River basin. We focused on Liangzi Lake, a freshwater protected area in
the Yangtze River basin, to understand the effect of a fishing ban
occurring after a short period of overfishing. In this aim, the time
series of fish community taxonomic and functional structure encompassing
the overfishing period and a post-ban period have been analyzed. Fish
community metrics with direct, indirect, and no responses to fishing bans
were identified. The results indicate that in the early period of the
fishing ban, the trophic level and body size structure of the fish
community were in the way of recovery. However, species that prefer
benthic habitats did not recover after fishing-induced habitat
degradation. Functional traits were more sensitive than taxonomic indices
and revealed subtle community changes, such as the recovery of some
ecological functions, despite a non-recovering species richness. Synthesis
and applications. This study provides a rare case of a freshwater
protected area in which the effects of conservation measures are studied
with a temporal survey. The effectiveness of the functional trait approach
in the application of protected area assessment was demonstrated by
revealing the recovery of trophic level and body size structure of fish
communities after the implementation of the fishing ban and the inadequacy
of habitat restoration efforts. We suggest that in freshwater protected
areas, insistence on a fishing ban is necessary but not sufficient for
full biodiversity recovery, and other measures are needed, such as habitat
restoration and species-focused stocking.