Fishing ban halts seven decades of biodiversity decline in the Yangtze River

China's rapid economic development has triggered an unparalleled freshwater biodiversity crisis since the 1950s. To restore fisheries resources, the Yangtze River Fishing Ban was implemented in 2021 to cease all basin-wide commercial fishing. We evaluate the effectiveness of this large-scale conservation action by assessing fish communities across mainstem habitats before and after the ban (2018 to 2023). The seven-decadal biodiversity loss was halted with improvements in fish biomass, body condition, species diversity, and initial recovery of threatened species. Eliminating fishing pressure was likely key to this recovery, in addition to actions targeting water quality improvement, hydrological and riparian habitat restoration, and vessel traffic reduction. Ambitious conservation actions can halt biodiversity loss in the Yangtze River, bringing hope for biodiversity recovery in other large rivers.