China has over 1,320 freshwater fish species, 877 of which are endemic. In recent decades, over-exploitation and landscape pressures have threatened them and led to a severe aquatic biodiversity crisis. In response, large-scale fishing bans or fishing closures have been promulgated to protect freshwater biodiversity in major Chinese rivers since the early 1980s.
However, implementing fishing bans alone is not sufficient to solve the crisis because of shortcomings of the current bans and expanding human pressures in most Chinese river basins.
The researchers first analyzed temporal trends and declines of freshwater mammals and fishes of the Yangtze River Basin, and discussed historical background, progress, and issues related to fishing bans in major Chinese river basins since the 1980s. They found that in the past 20-30 years, hydropower generation increased 23 times, sand mining maintained high, both total cargo volume and industry outputs increased nine times, and total urban population and total crop yields increased 1.5 and 1.4 times, respectively.
Based on the obtained results, the researchers then suggested six management programs/strategies to save China’s freshwater biodiversity crisis.
The most important thing is to promulgate legislation and regulations that set specific goals and quantitative targets for dischargers and receiving waters. When the goals are clear, comprehensive and effective adaptive management plans accompanied by ecological monitoring and assessment programs shall be implemented, and the monitoring and assessment data shall be available to the public.
Moreover, basin- and sub-basin-scale long-term (e.g., 10-15 years) fishing regulation and enforcement in natural water bodies rather than short-term seasonal bans shall be promoted. In the meantime, impacts from multiple anthropogenic pressures and stressors shall be qualified and all the pressures and stressors shall be regulated. The basin-scale ecological rehabilitation shall be initiated as well.
These programs are applicable to other nations where people largely depend on fish as food while facing biodiversity crises and expanding anthropogenic pressures. For instance, developing countries are experiencing similar economic development and rapid human population growth accompanied by ecological degradation of lakes and rivers.
Conceptual diagram illustrating the direct impacts of fishing and the indirect impacts of landscape pressures through habitat on freshwater biodiversity in Chinese rivers. (Image by IHB)
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