Coastal ecosystem, including the well-protected mangroves and coral reefs, could help substantially to reduce tsunami damage, according to Chinese conservation experts in Beijing Monday.

"The coastal ecosystem can not prevent tsunami attacks, but it could act as a buffer zone and dissipate much of the waves' destructive energy before they reach the shore," Li Xiaoming, director of the Marine Environment Department under China's State Oceanic Administration (SOA), said of the deterioration of the ecosystem along Chinese coastal lines due to the man-made damages to mangroves and coral reefs.

His view was echoed by Zou Xinqing, China program conservative director of the World Wide Fund for Nature (WWF). He described mangroves, coral reefs and coastal forests together as "a protective screen" for the coastal system.

"It's pity that mangroves and coral reefs along China's coast have suffered severe damages from human activities," said Li, adding that although protective steps are being taken, it still takes time for them to recover.

According to WWF, tropical coastal ecosystem have sophisticated natural insurance mechanisms to help them survive the storm waves of Typhoon and tsunami.

Coral reefs are equivalent to natural breakwaters, providing a physical barrier that reaches the surface, causing waves to break offshore and allowing them to dissipate most of their destructive energy.

In a report released here Monday, WWF estimated that in the Maldives, the damage from tsunami could have been much worse if the government's policy of protecting the network of coral reefs that buffer the islands from the open sea had not been diligent.

Globally, WWF estimated that coral reefs provide US$9 billion annually in economic benefits associated with coastal protection.

Mangroves act as natural shock absorbers, soaking up destructive wave energy and buffering against erosion, said the report.

"Healthy ecosystem can save lives," said Isabelle Louis, director of WWF's Asia Pacific Program.

"Places that had healthy coral reefs and intact mangroves were less badly hit by the tsunami than those where the reefs had been damaged and the mangroves ripped out and replaced by prawn farms and poorly planned beachfront hotels," she said.

According to the report, Indonesia had lost over 30 percent of its mangroves over the past 20 years, Thailand 50 percent, while Sri Lanka even more depleted. Meanwhile, large areas of coral reefs in the Indian Ocean region have also suffered extensive damages due to climate change and human activities.

The situation in China is no better. A report on China's marine environment released by SOA Sunday indicated that the ecosystem along the country's 18,000 km-long coast were fragile mainly due to over-zealous economic development and heavy pollution.

"The tsunami disaster in the Indian Ocean has served as a vivid reminder for us," Li said, pledging that SOA will closely monitor the changes of the ecosystem and take harder steps to curb ecosystem degradation.