The Yellow Sea in China is now green after the largest ever algal bloom ever recorded lapped ashore in the city of Qingdao.
The living carpet has been a annual visitor to these shores for the past six summers and is linked to agricultural and industrial pollution.
“I came to the coast planning to have a dip, but looking at things I dare not go in,” said a dismayed holidaymaker.
The explosion of algae points to a change in the ecosystem as a result of human activity, according to scientists.
The algae blocks sunlight from reaching the ocean and steals oxygen from the waters.