The coastline of Lianyungang City in China's eastern Jiangsu Province was covered with large patches of green earlier in June, resembling a savanna on the sea.
However, this "savanna" is, in fact, edible green algae widely occurring along coasts around the world.
Every year around July, the sea lettuce gathers on the sea around Jiangsu and often floats along the coastline reaching Qingdao City, which is around 200 kilometers away in Shandong Province.
Sea lettuce along the coast of Qingdao City in east China's Shandong Province. /VCG Photo
Even though the algae are not poisonous, they are still a headache for people who live along the coast. Under summer heat, the sea lettuce creates a stink. It multiplies at a rapid speed, covering large regions of the sea surface, and blocks sunshine for undersea plants.
Scientists have studied the species and discovered that sea lettuce can purify sea water by transforming carbon dioxide and nitrogen to water and oxygen, but dead sea lettuce consumes oxygen in the sea, causing a series of problems for the marine ecology.
Sea lettuce near Lianyungang City in July, 2018. /VCG Photo
One possible explanation for the explosion of sea lettuce is the rising sea temperature which brings up nutrition from the bottom of the sea to the surface, creating a perfect environment for the algae to grow.
(Cover image via VCG.)
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