The Yangtze River Basin, a global biodiversity hotspot, has endured severe ecological degradation over several decades due to intense human activity, leading to a marked decline in aquatic biodiversity. In order to halt this 70-year trend, the Chinese government instituted a comprehensive 10-year fishing ban on the Yangtze River in 2021.
The initial effects of the ban have now been evaluated. In a recent study, researchers led by Prof. CHEN Yushun from the Institute of Hydrobiology (IHB) of the Chinese Academy of Sciences, along with domestic and international collaborators, have revealed that the Yangtze River fishing ban has not only halted the 70-year decline in fish resources but has also triggered an initial recovery. The study was published in Science on February 12.
Based on systematic monitoring data from 2018 to 2023, the researchers comprehensively analyzed the dynamics of fish communities in the Yangtze's main channel before and after full enforcement of the fishing ban, examining dimensions such as fish species richness, biomass, abundance, evenness, and beta diversity. They also quantified the stressors affecting fish diversity, including water quality, hydrology, climate change, land use, shoreline development, shipping, and fishing pressure.
The results showed significant improvement in key indicators, including fish biomass, body condition, species diversity, and the initial recovery of threatened species. Notably, larger-bodied species benefited greatly from the fishing ban, showing significant increases in biomass, which was also evidenced by an increase in the fish condition factor for both larger- and smaller-bodied species.
Some species, such as the slender tongue sole (Cynoglossus gracilis), showed an increase in population after the ban, with their freshwater migration extending further upstream. Endangered fish species such as the Yangtze sturgeon (Acipenser dabryanus), Chinese sucker (Myxocyprinus asiaticus), and tube fish (Ochetobius elongatus), although still rare, also showed signs of initial recovery. However, the population status of Acipenser sinensis still faces an uncertain future.
In addition, the short-term recovery trajectory of the only extant freshwater mammal in the Yangtze River, the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), showed improvement, with its population increasing from 445 in 2017 to 595 in 2022, a gain of one-third.
By analyzing the links between conservation measures and biodiversity relationships using Generalized Least-Squares (GLS)-based Structural Equation Models (SEM), the researchers revealed that the fishing ban was the primary driver of the initial recovery of the Yangtze ecosystem. Other factors, such as reduced vessel traffic, the creation of riparian vegetation buffers, and improved water quality, also contributed to biological recovery.
The full fishing ban under the Yangtze River Protection Law has effectively halted seven decades of biodiversity decline. While short-term monitoring data show promising signs, the long-term sustainability of this recovery requires further verification. Future efforts should focus on consolidating the results of the fishing ban, systematically addressing multiple stressors, and promoting further coordination between ecological conservation and sustainable development.
