Chinese Sturgeon Struggling to Survive in the Yangtze

Chinese Sturgeon

The future of the Chinese Sturgeon, a large migrating fish that has survived in the Yangtze River for nearly 140 million years, is increasingly threatened by pollution, damming, overfishing, and heavy boat traffic in the waterway, according to a new report co-authored by the Yangtze River Water Resources Commission, WWF, and the Nanjing Institute of Geography and Limnology. Human activities have caused a general degradation in aquatic ecosystems throughout the river basin, the report says.

The sturgeon species, which can reach two to five meters in length and weigh 200 to 500 kilograms, once swam upstream from the East China Sea to the upper Yangtze River every spring to spawn, but this migration route has been blocked since the building of the Gezhouba Dam, the Yangtze’s first hydroelectric dam, in the 1980s. Although the government has established a special conservation area below the dam for the sturgeon to lay eggs, the number of the fish found in the river has dropped dramatically, from some 2,000 two decades ago to less than 500 today.

A large concentration of fertilizer, paper, textile dye, and metal processing manufacturers is located near the conservation area. The facilities’ considerable wastewater discharge contains nitrogen, phosphorous, toxic metals, and organic compounds, depleting oxygen in the water, disrupting the metabolism of the sturgeon, and even leading to malformation and gene mutation of the endangered fish, scientists say.

Aquatic experts are pinning their hopes on breeding technology as well as the release of young sturgeon into the Yangtze River each year to restore the species, but there has been little progress. Despite growing to normal size, the artificially bred fish have shown difficulty reaching sexual maturity, and there is little evidence of the successful survival of the young sturgeon in the river.

Fish are a symbol of prosperity in traditional Chinese culture, but stocks in the Yangtze are declining significantly. Since 2002, the Ministry of Agriculture has imposed a fishing ban in the river basin to prohibit trawlers from operating during the spring spawning period. But water pollution, construction, and sand mining along waterways pose big challenges for the preservation of fish habitat in China.