Scientists keep watch on red tides
( 2001-05-09 09:12 ) (1 )

Oceanographers are keeping watch on so-called "red tides'' on the shores of the East China Sea, but thus far this season the problem has been minimal.

To date, no massive and intensively destructive red tides had been seen, said an official with the Shanghai Oceanographic Bureau.

"During last several days, it has been rainy in the East China Sea area, but no immense red tides have occurred,'' said Yuan Ding, director of Marine Environmental Protection Division under the Bureau. "We cannot slack off now, though.''

Red tides, the rampant proliferation of algae in the sea, can result both naturally and from pollution and is sometimes attributed to sudden changes in water temperature. Such a situation can contaminate shellfish and alter the environment for other sea life.

They typically arise in the East China Sea during the rainy April-to-October period, Yuan said.

Red tides covered 20 to 30 square kilometres a few days ago in the sea off East China's Zhejiang Province, but it was not destructive, Yuan said.

The State has set up a monitoring network in the East China Sea of planes, satellites and enough manpower to keep watch over the next seven months.

"But the sea is too vast and our means to control them are limited,'' Yuan said.

Sources with the State Oceanographic Bureau said human activity, especially an increase of waste discharges and the burgeoning development of aquaculture has resulted in a rapid increase of nutrients in the water.

The problem has become severe in China in the past decade as a result of the country's accelerated economic development, and there is no indication the problem will be alleviated soon, according to the State Oceanographic Bureau.