River fishing ban seen to reverse biodiversity decline

In response to biodiversity collapse in the Yangtze river, China dramatically implemented a 10-year, full commercial fishing ban across the entire river basin

Since the 1950s, Yangtze fishery yields collapsed to a quarter of their historical peak, more than 130 fish species vanished from  surveys, and emblematic species such as the Yangtze River dolphin were driven to extinction. Picture:  AFP/AFP/Getty Images

Can banning fishing reverse biodiversity collapse in a mega-river? A new study published in Science suggests that, at least in the short term, the answer is yes. Drawing on six years of monitoring across 57 river reaches, Fangyuan Xiong and colleagues show that China’s unprecedented basin-wide fishing ban has halted seven decades of biodiversity decline in the Yangtze River. Crucially, the paper also highlights the scale of human transformation required to make such conservation work.

A river pushed to breaking point

The Yangtze supports around a third of China’s population and generates roughly 40% of national GDP. This economic success has come at a steep ecological cost. Since the 1950s, fishery yields collapsed to a quarter of their historical peak, more than 130 fish species vanished from recent surveys, and emblematic species such as the Yangtze River dolphin and Chinese paddlefish were driven to extinction. Overfishing interacted with dams, sand mining, pollution, and heavy navigation to push the river system toward ecological failure.

Despite major investment in protected areas and water-quality improvements, biodiversity continued to fall. In response, China escalated dramatically in 2021, implementing a 10-year, full commercial fishing ban across the entire basin. This was not a symbolic measure. More than 110,000 fishing boats were removed from the river, and over 230,000 fishers were resettled across 11 provinces at a cost exceeding US$2.7 billion.

Signs of ecological recovery

The ecological response documented in the study is striking. Comparing data from before (2018–2020) and after (2021–2023) the ban, total fish biomass more than doubled. Species richness increased by about 13%, and communities became more evenly structured, suggesting a shift away from degraded, simplified assemblages. Large-bodied fish, which are often the first victims of sustained fishing pressure, showed the strongest response, with biomass increases exceeding 230%. Smaller-bodied species declined slightly, a pattern consistent with reduced harvesting pressure allowing larger predators and competitors to recover. Importantly, fish condition improved across size classes, indicating better growth and nutritional status rather than short-term crowding effects.

Early signs of recovery were also detected among threatened and migratory species. Freshwater migration of slender tongue sole extended further upstream, while endangered fishes such as the Yangtze sturgeon and Chinese sucker, though still rare, increased in occurrence. Even the Yangtze finless porpoise showed a population increase of roughly one-third between 2017 and 2022.

Fishing pressure matters but people matter too

A major strength of the paper lies in its attempt to identify why recovery is happening. Modelling indicates that eliminating fishing pressure was the single most important driver of increased fish biomass and species richness. Improvements in water quality, flow management, riparian vegetation, and reduced vessel traffic provided essential supporting conditions.

But none of this would have been possible without addressing the human dimension. The fishing ban required an enormous social transition. Former fishers were not simply excluded from the river; many were retrained or supported into alternative livelihoods, including river patrol and enforcement roles, habitat restoration work, aquaculture, eco-tourism, and other non-extractive employment. In effect, people once dependent on fishing became stewards of recovery.

This matters because conservation policies that ignore livelihoods often fail. The Yangtze case shows large-scale ecological gains can be achieved when social support, compensation, and enforcement move together. Strict penalties and river police ensured compliance, but long-term success depends on whether alternative livelihoods remain viable and socially just over the full decade of the ban.

Lingering risks

The authors are careful not to overstate success. Six years is short compared with 70 years of decline. Large dams such as Gezhouba and the Three Gorges still block access to historical spawning grounds for migratory species, limiting true population recovery. Emerging stressors such as pharmaceutical pollution and altered flow regimes under climate change could continue to threaten long-term gains. There is also an unresolved question of durability. If commercial fishing resumes too quickly, or if social support for former fishers erodes, ecological recovery could unravel. The Yangtze’s progress is therefore best seen as a trajectory, not an endpoint.

A lesson for other rivers

Despite these caveats, this study delivers something rare in freshwater science; evidence that biodiversity loss in a heavily modified, economically vital river can be halted. It also demonstrates that ambitious conservation is as much a social project as an ecological one. Removing fishing pressure worked because it was basin-wide, enforced, and paired with substantial investment in people as well as habitats. For other great rivers under pressure, from the Mekong to the Amazon, the Yangtze experiment offers a powerful, if demanding, lesson. Recovery is possible, but only when political will, ecological science, and social transition move in step.

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