The Yangtze River fish is "anoxious" and the development of hydropower should not be excessive

Wudongde, Baihetan, Xiluodu, Xiangjiaba... In recent years, as the Three Gorges Project, which attracted worldwide attention, entered the final stage, the center of gravity of the Yangtze River hydropower development moved from the Three Gorges to the upper reach of the Jinsha River. A large-scale hydropower station, planned and under construction, turned out and rebuilt several Three Gorges Projects. In this booming hydropower development boom, the state-level nature reserves of rare and endemic fishes in the upper reaches of the Yangtze River have frequently been “encrusted”. Over-exploitation of “exhausting water and fishing” has repeatedly deprived rare fish of “survival rights”.

The “terraced” development nature reserve in the upper reaches of the Yangtze River was surrounded by “encirclement and suppression”

In 1994, the Three Gorges Project officially started construction and became a rated hydropower development project for the Yangtze River. Since the end of the 20th century, the development of hydropower in the Yangtze River has been further traced back to the Jinsha River in the upper reaches and the tributaries of the Ganjiang, Dadu, Yalong, Wujiang and Jialing Rivers. The Yibin-Chongqing reach of the mainstream of the Yangtze River has planned three water conservancy hubs from top to bottom: Shibo, Zhuyangxi and Xiaonanhai Hydropower Stations. The planned total storage capacity is 8.1 billion cubic meters and the total installed capacity is 5.03 million kilowatts. In the middle and lower reaches of the Jinsha River, a total of 12 cascade hydropower stations are planned for construction, with a total installed capacity of 58.58 million kilowatts, equivalent to three Three Gorges Projects. At present, of the 12 hydropower stations, the Jinan Bridge, Xiluodu and Xiangjiaba power stations have started construction, and other power stations have also carried out preliminary work.

The cascade development of the main tributaries of the upper reaches of the Yangtze River has also started on a large scale. From the vertical section of the layout of the Yangtze River Water Conservancy Project, the numerous hydropower stations to be built, under construction, and in planning, have cut the upper reaches of the Yangtze River into “layered terraces”.

Experts predict that, as it continues, the future of the upper reaches of the Yangtze River will become a huge reservoir group, and it will no longer be a real river with galloping and flowing.

While hydropower development is in full swing, the state-level nature reserve of rare and endemic fishes in the upper reaches of the Yangtze River has been forced to repeatedly develop “giving way”. According to He Jianhong, director of the Fisheries and Fisheries Bureau of Chuzhou City, Sichuan Province, the nature reserve consists of three functional areas: core area, buffer zone, and experimental area. The initial protection goal is to compensate for the negative impact of the Three Gorges Project on fish populations and the ecological environment, and to preserve the upper reaches of the Yangtze River. Natural ecological environment of the river.

However, with the start of hydropower development in the Jinsha River, the planned two dams, Xiangjiaba and Xiluodu, are located in the protected area. The protected area had to accept the fate of being “studded” and was artificially moved down to 1.8 kilometers downstream of Xiangjiaba in 2005. Just four years later, in the "tail" of the reserve, 1.5 kilometers downstream of the town of Chongqing, the early planning of the Xiaonanhai hydropower station was brewed and the protected area was once again in danger of being "tailed."

He Jianhong said that after being “stuck” in 2005, the scope and functional areas of the reserve have been adjusted. Although the area has been expanded, the core area of ​​the reserve is located in the river section where business activities are frequent, and conflicts with production and life are very serious. Large, it does not meet the requirements of the National Nature Reserve Regulations. According to the “Yangtze River Basin Comprehensive Utilization Plan” revised in 1990, after the completion of all upstream water level hubs, 30 spawning sites and concentrated distribution sites for rare and endemic fish will be inundated, and the core and experimental areas in the reserve will not be submerged. Re existed, leaving only 41.9 kilometers of buffer. The structure and function of the protected area will be lost and the protected area will be named.

Water flowing into the water, vigilance, superposition of over-exploitation of hydropower

Wang Jianwei, a researcher at the Institute of Hydrobiology, Chinese Academy of Sciences, said that most of the unique fishes in the upper reaches of the Yangtze River reproduce in flowing water and have a high dependence on river habitats. After the development of hydropower, the flowing water habitat in the reservoir area will become a hydrostatic habitat. After the impoundment of the Three Gorges Reservoir, most of the waters in the reservoir area are not suitable for endemic fish species. The species and quantity of endemic fish have been significantly reduced and they have been forced to migrate to the upper natural reserve. As the development of upstream hydropower is frequent and there are fewer and fewer flowing water habitats, the protected areas have become the only remaining stream of water in the mainstream of the upper reaches of the Yangtze River, but they face the fate of being eroded.

Cao Wenxuan, an academician of the Chinese Academy of Sciences and a researcher at the Institute of Hydrobiology, Chinese Academy of Sciences, said that although the current hydropower development project has proposed the construction of fish facilities and artificial fish breeding and other measures to protect fish, it has had little success. There are many fishes in the upper reaches of the Yangtze River, and their habits are different. It is impossible to build a fish pass that is suitable for all fish. With the dams now being built too high, fishway design investment is huge, and the effect of overfishing is difficult to guarantee. Artificial breeding and releasing can only be used as a remedial measure for rare species. It cannot be a major protection measure for all species, and it cannot be an economic act for fishing.

Scientific planning and moderate development are urgent tasks

First, before the major river basin planning has been completed, the development of small watersheds and hydropower projects will be suspended. In particular, some sensitive projects should be postponed.

Second, to strengthen research on fish resources and fish basic biology, attach great importance to the additive effect of water-level elevator development, and make scientific plans based on a clear understanding of the family background, discriminating impacts, and improving measures.

Third, strict implementation of appropriate development, to leave space for rare and endemic fish. There should be a limited and selective development of water resources in the basin, and a certain area of ​​flowing water habitats should be reserved between power stations to effectively mitigate the adverse effects of hydropower development.

Fourth, strengthen the construction and management of protected areas and do a good job in resource protection. Local governments and related agencies should actively cooperate with fish conservation actions, ban commercial fishing in protected areas, and control natural water fisheries activities to curb the decline of fish stocks.

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