The green algae floating towards east China's coastline is continuing to spread and has come ashore on beaches in Jiangsu Province and Shandong Province.
The algae is expected to be as severe as it was just before the 2008 Beijing Olympic Games.
The North China Sea Branch (NCSB) of the State Oceanic Administration said Tuesday the floating green algae has covered a 400-square-kilometer area in waters south of Qingdao, Shandong, with the northern edge of the expanse having entered Jiaozhou Bay Monday.
GREEN TIDE ONSHORE
A two- to three-meter-wide algae strip hundreds-of-meters long has formed at a beach on Xuejia Island in Qingdao, affecting the coastal city's tourism business.
"We used to have 5,000 to 6,000 tourists here on the beach, but now because of the green algae, only a few hundred come, which is a huge loss for me," said Sun Hongbin, who runs a motorboat business on the beach.
Zhang Ruiping, a tourist from Inner Mongolia Autonomous Region, said she had never seen the green algae before.
"It's so disgusting. I have no mood to walk along the beach any more," she said.
"I dragged my three-year-old son away after learning a boy was almost killed after being trapped by the foul-smelling thing," she added.
Zhang's tour group has decided to shorten their stay in Qingdao from three days to two, and visit Shanghai Expo ahead of schedule.
The algae expanse is expected to float northward at a speed of seven to nine kilometers per day over the next three days to reach the beaches of Langyatai Bay, Guzhenkou Bay, Lingshan Bay, Tangdao Bay and Tuandao Island.
"The algae issue is more serious than last year, maybe similar to the situation in 2008," said Sun, who has witnessed the "green tide" the past four years.
The algae almost sabotaged the sailing regattas of the 2008 Olympic Games held in Qingdao.
Nearly one million tonnes of it was cleared from the sea and buried underground to allow the sailing regattas to take place, the Beijing Organizing Committee for the Olympic Games sailing committee said in August 2008.
The algae kills a large amount of marine life as the algae consumes large amounts of oxygen and blocks sunlight, causing 200 million yuan (29.43 million U.S. dollars) in economic losses for local fishermen, said Wu Wei from the oceanic and fisheries department in Qingdao.
The Qingdao city government organized 66 vessels for the algae clean-up. Four other vessels monitored the algae's movement.
About 700 hundred people, including tourism company staff and coastal residents, have participated in the clean up, said Sun, who also joined in the clean-up work.
AGRICULTURAL INDUSTRIES BLAMED
The green algae first appeared in the Yellow Sea in 2007.
Its appearance was a sign of oceanic environmental degradation, Professor Pang Shaojun, a researcher from the Institute of Oceanology under the Chinese Academy of Sciences (IOCAS), said.
Pang said the agricultural industries of coastal residents have caused the growth of excessive nutrients in the ocean, providing a favorable environment for the green algae.
However, research carried out last October found no algae of earlier forms off the Qingdao coast, which means it might have drifted with the marine currents from the sea off neighboring Jiangsu Province, Pang said.
"Instead, we found about 3,000 individuals of algae in their microscopic stage in every liter of seawater off Jiangsu, which includes the current existing form off Shandong coast," said Dr. Liu Feng from IOCAS.
Being the largest river crab breeding base in China, Jiangsu infused breeding ponds with foul manure to promote the growth of rotifer, a plankton that serves as crabs' food to speed up the growth of crabs, Pang explained.
The manure-laced pond water has excessive amounts of ammonia nitrogen, which is essential in the formation of proteins for cell growth.
The water brought about a wild outburst of green algae after it was discharged into the sea, said Pang.
Wu Jianxin, associate professor of marine science at Jiangsu-based Huaihai Institute of Technology, shared the opinions of Pang, but he thinks agricultural fertilizers also account for the algae.
People rely on nitrogenous fertilizer to increase the output of grains, and a lot of fertilizer has ended up in the sea after dissolving in rainwater, which helps the algae grow in the seawater, Wu said.
It grew at a speed of 36 percent per day, so it was impossible to eliminate by clean-up only, said Liu Feng.
"Even though it has cleared this year, the huge amount of remaining algae will exist in the Yellow Sea for quite a long time, and it will continue to spread next year when it becomes warmer," he said.
Pang suggested the central government set up a special fund and organize experts for green algae research in order to find out the exact reason for its spread. Then the fundamental problem can be tackled.