"Wild animals must have a complete living environment and the dam has affected their living conditions. Their extinction was forecast when the Gezhou Dam was built," said Xie Yan, a researcher with the Institute of Zoology of the Chinese Academy of Sciences.

But to their surprise and joy, researchers discovered that sturgeons have found a series of new sites for reproduction further downstream of the dam. But the new spawning sites, which are alongside a reservation area, are fragile and have all suffered under new engineering projects. In 2004, an embankment was set up downstream, which directly destroyed the new spawning grounds.

In light of the severe situation, the Chinese authorities have taken efforts to save the precious fish. In 1988, the Chinese sturgeon was listed as under the highest level protection. Since the 1980s, fishery authorities started curtailing fishing along the Yangtze River and created conservation areas below the Gezhou Dam.

Meanwhile, attempts are also being made to restock the fish's shrinking numbers by breeding millions in captivity and then releasing them into the rivers that they are native to. Recently, many research laboratories have even started hatcheries.

In May 2014, Shanghai started building a research center in Chongming Island to study and help support the recovery of the endangered Chinese sturgeon.

The 55,900-square-meter center will include a workshop for rescuing and temporarily rearing Chinese sturgeons, a laboratory and other support facilities, according to the Shanghai Agricultural Commission. Staff will rescue, raise and breed sturgeons and other endangered species, as well as conducting studies and spreading knowledge among the public, authorities said.

An inefficient method

In April, 70 Chinese sturgeons, whose lengths were between 1.5 and 2 meters, were released into the Yangtze River by research staff to increase the number of the endangered species.

Each year in April, some artificially bred sturgeons were released into the river. In 2012 and 2013, 1,200 and 8,000 sturgeons were reintroduced into the Yangtze River respectively.

Over the past three decades, more than 5 million artificially bred Chinese sturgeons have been reintroduced into the wild, according to the Yichang-based Chinese Sturgeon Research Institute.

Since the 1980s, scientists have started attempting artificial breeding of Chinese sturgeons and reintroduction into the wild. Chinese scientists have also cooperated closely with foreign counterparts in protecting the endangered species. The Yichang-based Chinese Sturgeon Research Institute and the Wuhan-based Yangtze River Fisheries Research Institute under the CAFS are leading in this area.

In 1983, the two institutes achieved breakthroughs in artificial breeding technology—collecting eggs by dissecting the live female Chinese sturgeons. "However, this way is very cruel. Most of the sturgeons did not survive," said Gao Yong, Director of the Chinese Sturgeon Research Institute.

With the technology available at the time, artificially bred baby sturgeons could only grow to 2-3 cm in the laboratory. "The fish could not survive in the laboratory, let alone in the wild," Gao said.

In 1995, breeding technology saw another breakthrough. This time, fertilized eggs of the Chinese sturgeons could be hatched and bred into 10-cm-long baby fishes.

In 2009, 28,000 fertilized eggs were successfully collected in an experiment in artificial propagation of the sturgeon, and in 2012, some of 50,000 fertilized eggs gleaned from Chinese sturgeon hatched, declaring that the institutes have achieved the capability to breed the second-generation sturgeons.

According to Yang Yuanjin, Deputy Director of the Chinese Sturgeon Research Institute, the second-generation fish refer to those bred based on the first-generation ones, while the first generation are those artificially bred from the fertilized eggs of wild ones.

Despite the progress, scientists still reserve doubts to the real effects of the artificial breeding of the Chinese sturgeons. According to Wei with the CAFS, there is no obvious proof to testify the method. "The only thing I know is that a monitoring of the Yangtze estuary shows that the population of artificially reproduced fish accounts for only 5 percent of the total sturgeon population," Wei said. 

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