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.

(Xinhua News Agency June 30, 2010)