Around 110,000 Chinese sturgeon were among more than 400,000
rare fish released into the Yangtze River yesterday 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 7 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 fishing ban.
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 the institute.
Chen said the number of sturgeon in the Yangtze was unknown, but
it was at least 500.
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 cannot
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.
(Xinhua News Agency April 23, 2007)
