Four species of domestic carp of the Yangtze River laid a record number of eggs in 2017, thanks to water flow controls of reservoirs.
From late April to early June last year, more than 1 billion eggs of the four species were monitored at Yidu in the middle reaches of Yangtze, the most since 2011, according to Changjiang Water Resources Commission.
Since 2011, the Three Gorges Reservoir on the river has regularly adjusted its volume of water to create good conditions for spawning.
Natural spawning of the four species requires a water rise by 0.3 to 0.5 meter in a day for seven to 10 consecutive days.
During the water adjustment last year, two upper reservoirs, Xiangjiaba and Xiluodu supplied water to the Three Gorges.
The two reservoirs made the efforts to help fish spawn more effectively, and helped alleviate impact of the Three Gorges on fish spawning, said Chen Min, director of the commission.