亚洲精品久久久久久一区二区_99re热久久这里只有精品34_久久免费高清视频_一区二区三区不卡在线视频

Scientists with a Chinese sturgeon conservation authority announced on Monday that the population of the rare fish in the Yangtze River appeared to have dropped sharply since last year.

 

A report from the Shanghai Yangtze Estuary Chinese Sturgeon Conservation Administration said that by last Wednesday, scientists had located just 14 young sturgeon in the Chongming monitoring base, an area where the fish are believed to gather, compared with 600 at the same time last year.

 

"We used the same methods to trace the fish at the same time and place, but unfortunately that's the result we got," said Liu Jian, director of the administration.

 

The report said at least 100,000 Chinese sturgeon had been released into the Yangtze this year to restock the river. In Shanghai alone, about 2,156 artificially-bred fry were released, but only five had been detected to date.

 

Since November last year, 11 adult Chinese sturgeon had been found dead, most killed by ship propellers and some in electrified fishing nets, said Liu, adding that two sturgeon remained severely injured.

 

On June 17, a 3.37-meter Chinese sturgeon was caught by fishermen who were netting jellyfish at Jinhui port in Shanghai. The fish, which suffered multiple lacerations, was recovering in the conservation area.

 

Liu said the fish could need another two months to completely recover.

 

"What we have found, the deaths and injuries, are abnormal, and we fear they may be a bad omen for the ecological environment of the Yangtze," Liu said.

 

The Chinese sturgeon, one of the oldest vertebrates in the world, has existed for more than 200 million years.

 

However, rapid economic development, over-exploitation of the river and shocking levels of pollution have taken a terrible toll.

 

Scientists with the Yangtze River Fisheries Research Institute said the number of sturgeon that migrated to the river each year to spawn had dropped from more than 2,000 in the 1980s to just 500.

 

A report on Yangtze River protection and development says that more than 600 kilometers of the river are in critical condition, and pollution, damming and too many boats have caused a dramatic decline in Yangtze aquatic life.  

 

(Xinhua News Agency July 23, 2007)