Dead fish lie in a pond at a fish cultivation base in Gutian county, Ningde city in east China's Fujian Province, Sept. 3, 2011. Millions of dead fish have been found in several townships in the county since Aug 31, with reported loss of up to hundreds of millions yuan. The cause of the mass death remains unknown. Fishermen said it could be due to the pollutant discharged from the enterprises in the upper reaches in rainy days. [Photo: Xinhua]