Four major species of Chinese carp in the Yangtze River have spawned nearly 100 million eggs, thanks to the water flow controls of the Three Gorges reservoir, China's water resource ministry said Tuesday.

From May to June, the reservoir in central China's Hubei Province carried out two ecological operations, increasing water outflow to create flood peaks to stimulate spawning.

Three spawning peaks were monitored in the middle reaches of the river during the period, said the ministry's hydroecology institute.

Natural spawning of the four major Chinese carp species, namely black carp, grass carp, silver carp and bighead carp, requires suitable water temperatures and rising water levels.

Since 2011, the reservoir has regularly adjusted the volume of water flows to create ideal conditions for spawning.

The reservoir will continue to explore ways to restore the wetland environment in the lower reaches of the Yangtze and protect the habitats of aquatic life via such operations, said the institute.