Ecological degeneration of the Erhai Lake and prevention measures

Abstract

The water quality of Erhai Lake is good as a whole, but its decreasing trend is not optimistic; the water ecosystem of Erhai Lake has changed dramatically, showing an obvious degenerating trend. The main reasons for the ecosystem degeneration are as follows: inflow pollution load exceeding the water environmental capacity, not favorable water habitat for the propagation of submerged plants, and the weak management for the lake basin. To prevent the degeneration of Erhai ecosystem, two key problems should be solved: one is to reduce the inflow pollution load to prevent the increase of nitrogen and phosphorus concentrations in the overlying water; and the other is to implement the ecosystem regulation, namely improve the stability and biodiversity of Erhai ecosystem by habitat improvement, ecological restoration and ecological regulation. In terms of the preventive measures against the Erhai ecosystem degeneration, the pollution source control in combination with ecosystem regulation should be taken as the focus. Pollution source control, habitat improvement, ecological restoration, ecological regulation and watershed management should be emphasized simultaneously. To be specific, the key tasks for preventing Erhai ecosystem degeneration include five points namely, the reduction of pollution loading into lake, adjustment of ecological fishery, restoration of submerged vegetation, watershed integrated management, and emergency treatment of water blooms.