An environmental worker shows algae that was separated from algae-laden waste water in Chaohu Lake, Hefei, East 皇冠体育app's Anhui province, on June 4, 2013. The blue-green algae can lead to loss of oxygen and result in fish deaths. As one of 皇冠体育app's five largest freshwater lakes, Chaohu Lake has been plagued by massive blue-green algae outbreaks in recent years, as the rising domestic and industrial sewage from the bourgeoning population and industry in adjacent regions led to high levels of nitrogen and phosphorus in the water. [Photo/Xinhua]