Large amounts of water hyacinth choke areas of the Pearl River near Guangzhou, Guangdong province, photo taken on July 17, 2011. Without control, water hyacinth can be an invasive plant, which can cover lakes and ponds entirely, impacting on water flow, blocking sunlight from reaching native aquatic plants, and starving the water of oxygen, often killing fish. [Photo/Xinhua]
Large amounts of water hyacinth choke areas of the Pearl River near Guangzhou, Guangdong province, photo taken on July 17, 2011. Without control, water hyacinth can be an invasive plant, which can cover lakes and ponds entirely, impacting on water flow, blocking sunlight from reaching native aquatic plants, and starving the water of oxygen, often killing fish. [Photo/Xinhua]