The fish species in the upper branches of the Yangtze River have declined dramatically in recent years, imposing a severe warning on the river’s ecological system which has been much endangered, the Ministry of Agriculture revealed recently.
According to a collaborative report led by the ministry’s Yangtze River Fishery Resources Management Commission Office, the ecological system of the upper branches of the Yangtze River has collapsed and as a result many precious fish species are now on the brink of extinction.
The number of precious species, including reeves shad, sturgeons and puffer fish, has continued to drop in recent years.
A long-term data monitoring system located in the upper branch of the river by the Chinese Academy of Sciences also proved the reports to be true. According to aquatic experts, the number of the four carp types — black carp, grass carp, silver carp and bighead carp, which used to be abundant in the river — has also plummeted from 30 billion to no more than 100 million in the past 60 years.
According to the ministry’s Yangtze River Fishery Resources Management Commission Office, who conducted the research in June this year, the diversity and ecological environment of the Yangtze River have all been threatened. They made the statement after scrutinizing fish samples collected from the Chin-sha River (the up branch of Yangtze River) along Yushu, Qinghai Province, Shigu, Yunan Province, and Chishui, Guizhou Province. The fish species went from 143 during the previous research to a mere 17.
Wen Lida, director of the Yangtze River Water Resources Protection Bureau, said that in addition to over-fishing and pollution, a major reason behind the sharp decline of fish species in the Yangtze River is the disordered construction of dams.
After the construction of the Three Gorges, dams are burgeoning in the Yangtze River. According to a report on the comprehensive use of the Yangtze River, three hydropower generators — Shipeng, Zhuyangxi and Xiaonanhai — with a total reservoir capacity of 8.1 billion cubic meters are designed to be located at the main stream, running from Yibin to Chongqing, Sichuan Province, of the Yangtze River. The middle and lower branches will accommodate 12 generators with a total capacity of 58.58 million KW, equivalent to the tripled capacity of the Three Gorges Dam.
Environmentalists believe evaluations of the hydropower projects are not comprehensive enough to forecast its negative impact on the middle and long terms.
Cao Wenxuan, the academician and aquatic species researcher from the China Academy of Sciences, said that although artificial breeding was seen as a measure to counteract the loss of fish species in Yangtze River, results are not optimistic. If the generators are all put into operation, the lowered temperature and the changing stream will all affect the precious fish species in the river and cause irreversible damage.
Many experts call on the government to control the development in an appropriate scale in a bid to counter the deteriorating eco-environment in the Yangtze River, make a new and feasible evaluation of the dams, especially the small ones, and encourage research on and natural conservation of the living aquatic species.