Coral reefs escape severe damage by Asian tsunami

Almost 90% of coral reefs hit by the Indian Ocean tsunami escaped severe damage, according to research.

Study of 175 sites along 435 miles of Thailand's west coast found 60% of reef suffered little or no damage.

Just 13% was severely damaged in the tsunami which killed more than 220,000 people, but scientists expected that to recover in five to 10 years.

The findings are to be presented to the Royal Geographical Society's annual conference in London on Tuesday.

The study found the most northerly coast and islands more damaged than those further south, with shallow reefs on wave-exposed islands and shorelines most vulnerable.

Areas counted as severely damaged if at least half of the coral was broken or overturned.

Damage could have been caused both by the force of the wave, and stirred-up sediment smothering the coral.

In other areas, coral was dying because the earthquake had lifted the seabed and placed the coral on dry land.

Quake impact
But the University of Newcastle's Professor Barbara Brown, who worked alongside Thai researchers, said: "The initial results for Thailand are very encouraging and the resilience of the coral in this area will aid a fast recovery."

She said reefs had suffered greater damage on the coasts of the Indonesian island of Sumatra and India's Andaman and Nicobar islands because they had been hit by the original earthquake as well as the subsequent tsunami.

"A conservative estimate would suggest that many kilometres of shallow coral reef has been killed by uplift caused by the earthquake alone in these locations," the emeritus professor of Tropical Marine Biology said.

Coral reefs stretch from the surface of water down to the limit of light penetration - about 30m deep.

A healthy reef acts much like a natural breakwater and there is evidence they gave some coastlines a little protection - but also took some of the blow.

Source: news.bbc.co.uk