Swimming in slime – Tourists swim in seawater covered by a thick layer of green algae on July 3, 2013 in Qingdao, China. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit the Qingdao coast in recent days.
Swimming in slime – For the seventh year in a row, monstrous quantities of green algae have sprouted in the coastal waters near Qingdao.
Swimming in slime – This year's growth, covering 28,900 square kilometers (11,158 square miles), is the biggest outbreak ever recorded, state-run news agency Xinhua reported.
Swimming in slime – Tourists play at a beach covered by a thick layer of green algae on July 3 in Qingdao.
Swimming in slime – Chinese officials have blamed past algae outbreaks on unusually warm seas. But scientists say that agricultural waste, industrial pollution, and human sewage are often to blame.
Swimming in slime – A file photo from the 2008 cleanup. A researcher says that algae does not typically cause health problems, but skin inflammation may be a risk. "If you were stupid enough to go in, I wouldn't go in naked," said Dr. Christopher Bolch, of the University of Tasmania.