Ecological security problems of the major key lakes in China

On the basis of the historical data and filed investigations, the ecological security situation of the six major key lakes (including Taihu Lake, Chaohu Lake, Dianchi Lake, Hongze Lake, Poyang Lake and Dongting Lake) in the period from 1980 to 2008 was identified. The obtained results indicate that the overlying water of Taihu Lake, Chaohu Lake, Dianchi Lake and Hongze Lake was seriously polluted. The safety of drinking water had been seriously threatened, the biodiversity declined and the aquatic vegetation severely degraded. The shore areas of the lakes had been exploited and the wetlands around were continuously eroded. Water bloom was proved to be a difficult and seriously ongoing issue threatening ecological security. The less polluted Poyang Lake and Dongting Lake were found to have suffered ecological security problems as well. These issues include vegetation degradation, the threat to biological habitat, increased pollution load into lakes, eutrophication, the depressed fisheries resources and rare birds' being threatened. Ecological security in the key lakes is threatened by rapid economic and social development in the basins. A large quantity of industrial pollutant emissions and the overuse of agricultural fertilizers and pesticides can be attributed to the rapid development mentioned above.