Algae Blankets China Beaches
A child plays on an algae-matted beach in the coastal city of Qingdao in east China’s Shandong Province earlier this month.
By Ker Than, National Geographic.
Local authorities and residents in the popular tourist destination have been struggling over the summer to remove a large mass of green algae that has washed ashore. As of late June, the algae bloom, or green tide, covered more than 170 square miles (440 square kilometers) of coasts south of Qingdao.
The algae blanketing the city’s beaches belongs to a species of marine plankton known as Enteromorpha prolifera. The algae can be found in waters all around the world, and can explode in so-called macro-algal blooms if conditions are right, said Steve Morton, a marine biologist at the National Oceanic and Atmospheric Administration (NOAA).
Such massive blooms require warm ocean temperatures and waters rich in the elements phosphorus and nitrogen, which are found in fertilizers and can be carried to the coasts by water runoff. While the algae isn’t toxic, big blooms can create oxygen-poor “dead zones” in the water and leave an unpleasant odor on beaches.
Workers remove large mounds of algae from Jinshatan beach on Qingdao’s Yellow Island this summer.
China is notorious for its algae blooms. During the 2008 Summer Olympics in Beijing, a sailboat race was almost canceled because of an outbreak. “They had thousands of people raking the ocean to get the algae out,” NOAA’s Morton said. “It was an amazing sight.”
Macro-algal blooms are a uniquely modern problem that emerged after humans learned how to create potent artificial fertilizers in massive amounts, added Wayne Litaker, a research scientist also at NOAA.
“In the 1800s people had to use natural fertilizers such as guano,” which is the excrement of birds, bats, and seals, Litaker said. Now that we have artificial fertilizers, “a lot more goes onto the land than ever before.”
A Chinese man walks along a Qingdao beach completely blanketed by algae.
Thick Enteromorpha algae blooms block the small amounts of sunlight that reach deeper-dwelling marine life. And when the algae die, their remains are broken down by fungi and bacteria that suck up oxygen, creating ocean dead zones, Morton explained.
An algal bloom is a feast for the microscopic decomposers, and the dead zones can persist for months as a result.
Photos Source: Imaginechina/AP
