This picture taken on July 22, 2015 shows a man swimming amid algae at a beach in Qingdao, in eastern China's Shandong province. The algal phenomenon, an annual occurrence in Qingdao, is usually caused by an abundance of nutrients in the water, especially phosphorus, although the triggers for the enormous blooms which began to appear in the Yellow Sea in 2007 remain uncertain. (Photo by AFP Photo/Stringer)
