Natural spawning of rare Chinese sturgeons first spotted in three years

Scientists have discovered evidence of spawning by wild Chinese sturgeons in the Yangtze River for the first time in three years, the Chinese Sturgeon Research Institute said Thursday.

The spawning period for the rare fish is from October to November, and the last time the activity was spotted was in mid-November 2012, said Jiang Wei from the institute.

Over the three years from 2013 to 2015, researchers failed to monitor any spawning in the section of the Yangtze River downstream of Hubei Province's Gezhouba Dam -- the only known spawning ground of the species.

Born in the Yangtze, the sturgeons migrate to the sea like salmon, where they mature before returning to their birthplaces to spawn. Previously, they returned to Jinsha River, a major tributary of the Yangtze, but with the construction of the Gezhouba Dam across the main stream of the Yangtze in 1981, the migration route was cut off. Clearly they have found a new spawning site, downstream of the dam.

For more than 20 years, researchers found spawning sturgeons in autumn and winter downstream of the dam, but none have been seen since 2013. However, researchers found signs of hope in April 2015 when they discovered a large school of juvenile sturgeons in the Yangtze estuary.

The institute has strengthened its monitoring work since November. Finally, the spawning activities were captured by monitoring equipment about 400 meters downstream of Gezhouba Dam in the early hours on Thursday.

Jiang said the discovery relieved concerns that wild Chinese sturgeon have lost the ability to reproduce. "The natural breeding activity of Chinese sturgeons never stopped." Endi