CTG releases 250,000 Chinese sturgeon into Yangtze River

A total of 250,000 captive-bred Chinese sturgeon were released into the Yangtze River on April 9 in Yichang, Hubei province to help restore the fish's wild population, according to Chinese Sturgeon Research Institute of China Three Gorges Corp.
The release is also the largest one in terms of numbers. It marks the 65th sturgeon-releasing activity the company held so far. To date, CTG has released over 5.27 million Chinese sturgeons into the Yangtze River, among which 258,000 are second filial generation.

Known as one of the oldest vertebrates on Earth, the Chinese sturgeon has existed for 140 million years. Due to overfishing and water pollution, the wild stocks have continued to diminish since 1980s. In 1988 China listed Chinese sturgeon as a key protected wildlife species at the national level. In 2010 Chinese sturgeon was upgraded to a Critically Endangered status by the International Union for Conservation of Nature.

The Chinese sturgeon is a typical anadromous species and spends 90% of its life in the ocean, the details of which is unknown to us. CTG’s research institute therefore launched a study on the Chinese sturgeon’s life cycle in the ocean in 2021. As part of the study, 38 Chinese sturgeons released this year were implanted with satellite and sonar tags so that researchers are able to monitor their activities on their way to the sea and back to the river, assess the range of their distribution offshore, and analyze the key environmental factors that impact their survival in the wild and pattern of activities.

Researchers have made major breakthroughs in screening and verification powered by DNA molecular tagging technology over the past few years. “We are able to confirm whether a captured Chinese sturgeon was one of those released by us simply based on a fragment of its tissues, for example, a tiny strip of its fin, sequenced and compared with our database. This turns into a genetic ID that accompanies the fish throughout its life,” said Jiang Wei, chief engineer with the CTG’s Chinese Sturgeon Research Institute.

Based on artificial propagation and technological progress over more than three decades, the institute has built a complete echelon of the artificially bred group and mastered the technology of fully artificial propagation. Its four rare fish conservation bases along the Yangtze River, for example Wudongde Lab, Xiangjiaba Lab, Three Gorges Lab and Yichang Lab, achieved several breakthroughs in the technology of artificial propagation of over 10 rare fish species including the Yangtze sturgeon and Coreius guichenoti.

CTG has to date released over 10 million rare fish of various species. It now plans to release 1 million rare and endemic fish including the Chinese and Yangtze sturgeon during China’s 14th Five-year Plan period. CTG will also launch the “Noah’s Ark” plan for rare and endemic fish species, aiming to build dedicated banks that hold the milt, cells and genes of the fish.