The First Ecology Adjustment Trial of Three Gorges Project Succeeded

The first ecology adjustment trial of Three Gorges Project succeeded. The Ministry of Yangtze River Water Resource published the first ecology adjustment trail monitor result of June in a few days ago. This result showed that the first time adjustment trial promoted the natural propagation of the "Four Great Fishes" (herring, grass carp, silver carp and big head carp), and it is meaningful for decreasing the effect of Three Gorges Project to ecological environment.

It is reported that this is the first time to carry out ecological adjustment which aimed at natural propagation of fishes. This adjustment caused the water level in middle stream and downstream hydrological stations continuously increased for four to eight days. To compare this monitor result with early monitor results, we can find that the time to lay eggs of "Four Great Fishes" is same as it under the natural condition. This preliminary trial proved that the ecological adjustment promoted the "Four Great Fishes" natural propagation.

Xu Deyi, who is the office chief and press spokesman of Yangtze River Water Resource Commission, said that the main stream of Yangtze River is main native habitat of the "Four Great Fishes" and which is the spice affected by Three Gorges Project. From April to September in every year is the spawning period of "Four Great Fishes". The natural propagation needs some specific hydrologic condition, such as continuous water level increasing, a certain water flow speed, and over 18℃ water temperature and so on. After water storage in Three Gorges Reservoir, the natural advantages of river were changed; especially the specific hydrologic condition for "Four Great Fishes" propagation changed.

In order to promote the natural propagation of the "Four Great Fishes" in middle stream of Yangtze River, under the premise of ensuring safe, Yangtze River Flood Control and Drought Relief Headquarters Office organized the ecological adjustment and simultaneous monitoring of Three Gorges Reservoir in June. Through adjustment, the daily average outflow of Three Gorges Reservoir increased 2000 cubic meters every second. During the adjustment period, the outflow amount of every second increased to 19000 cubic meters from 12000 cubic meters.

It was introduced by Xu Deyi that Three Gorges Project will carry out ecological adjustment from middle of April to end of June, and to launch related monitor work in the future four or five years to optimize reservoir operation.