Around 110,000 Chinese
sturgeon were among more than 400,000 rare fish released into the Yangtze River
on Sunday in a new attempt to save the river's fish stocks from being wiped out.
The fish, released at 11 sites in nine cities, included 280,000 mullet, which
was listed with the sturgeon as a protected species, said Zhang Xianliang,
director of the Yangtze River Fisheries Research Institute.
More than seven million sturgeon have been released into the Yangtze since
1983, but Zhang said this was the first occasion in which such a large number of
rare fish had been released into the river at one time.
Zhang said conditions were appropriate for the release with the water
temperature at 10 to 16 degrees Celsius and the Yangtze currently under a
Decreasing river levels and pollution have taken their toll on fish stocks.
The number of sturgeon that migrate to the Yangtze each year to spawn has
dropped from 2,176 in 1987 to just 500 now, said Chen Xihua, a researcher from
Chen said the number of sturgeon in the Yangtze was unknown, but it was at
To boost fishery sources, China has increased efforts in breeding and
releasing them back into the water, he said.
But many sturgeon released in the 1980s and 1990s died as breeding techniques
were not as effective as those at present, Chen said, adding they have worked to
improve techniques and increase their survival chances.
Liu Denghong, a researcher with the Chinese Sturgeon Research Institute, said
about 30 conservation areas had been built along the Yangtze to protect fish
stocks, including the sturgeon.
In Jingzhou city, central China's Hubei Province, about 50,000 sturgeon bred
at the institute were released. "They have been raised in a water quality
similar to that of the river, and should adapt soon," said Li Luoxin, a
researcher at the institute's sturgeon breeding center.
Li said the sturgeon usually stayed in deep water, where they could better
avoid the dangers of the river such as large boats and fishermen.
Two wild Chinese sturgeon, about three meters long, one weighing 451 kg and
the other 150 kg, were also released back into the Yangtze, said Liu Jianyi, a
researcher with the institute.
They had been in the Beijing Oceanarium for the last two years after being
injured in the Yichang section of the Yangtze River in Hubei.
Liu said they had marked all the sturgeon and planted sonar devices and chips
in some to follow their progress. "If they can not adapt, we will get them back
into the institute for recuperation," Liu said.
The Chinese sturgeon is one of the oldest vertebrates in the world and has
existed for more than 200 million years.