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green algae

QINGDAO, CHINA - JUNE 28: A child plays at a beach covered by a thick layer of green algae on June 28, 2013 in Qingdao, China. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, has arrived on the coast of Qingdao and neighboring cities in Shandong province. The seaweed has grown at a rapid rate due to marine water eutrophication and warm weather. (Photo by Hong Wu/Getty Images)

Sea of green: Chinese algae beach

Huge swathes of blue-green algae have covered the beach in Qingdao, China. The bizarre sight is caused by algae called 'enteromorpha prolifera', which is non-toxic and keeps returning even though 20,000 tonnes have been removed in recent weeks.