Crédito: Claudio Contreras
Coral Reefs the Silent Victims of Asian Tsunami
Por Sonny Inbaraj
The gigantic waves of Dec. 26 caused large-scale destruction of the barrier reef of Andaman and Nicobar islands, the largest in South Asia and the source of sustenance for local communities, reports our special Tierramérica contributor from Thailand.
As rescue teams frantically search for people who survived the killer waves that lashed the coastlines of South and South-east Asia the day after Christmas, marine biologists, divers and government officials in the region are trying to estimate the damage done to the Andaman Sea ecosystems.
While initial surveys along Thailand's western coast indicate that the damage may not be as bad as feared, there are concerns that large stretches of natural oyster beds and coral reefs across the southern Indian coast could have been completely washed away by the tsunami, spawned by a 9.0 undersea quake, killing more than 150,000 people.
The zone of influence of the Andaman Sea, in the eastern Indian Ocean, includes Thailand, India, Burma, Indonesia and Malaysia.
The tsunami caused large-scale destruction of the coral reefs of the Andaman and Nicobar islands, the largest in southern Asia. Scientists believe it will take a long time for this precious ecosystem -- home to some 200 types of coral and 400 fish species -- to recover.
The Andaman and Nicobar reefs, surpassed in extension and biodiversity only by the Great Barrier Reef of Australia, have been almost ''wiped off the aquatic map of the Indian Ocean,'' says N R Chattopadhyay, dean of Fishery Sciences at the Kolkata-based University of Animal and Fishery Sciences.
These coral reefs nurture thousands of marine species in the chain of islands, he told Tierramérica.
''This is our first experience with the tsunami waves,'' Chattopadhyay said in an e-mail interview. "However, the devastation it has caused to marine life, especially the coral reefs and natural pearl oyster beds, will take a long time to heal.''
Coral reefs are key to the economic and social development of the countries where they exist. The fish stocks of the reefs are a vital source of food and work: in South-east Asia alone, they generate more than 2.5 billion dollars a year, according to the World Wildlife Fund.
''Whether the coral reefs in the Andamans can recover would depend on the extent of the immediate damage caused by the fast and high waves and the inevitable post-tsunami siltation of the reefs,'' said D.R.K Sastry, India's Zoological Survey's regional director in the Andamans.
In Thailand, however, biologists said that while the tsunami rose to a height of up to 11 meters above normal sea levels when it crashed ashore around the islands of Phuket, Phang Nga and Krabi, under the surface of the water there appeared to have been relatively little movement.
''Right after the tsunami, we rushed to major coral reef sites where we feared the damage would be incalculable. We were relieved to find that several places were not hopelessly devastated at all,'' said Ukrit Satapoomin, head of the Phuket Marine Biological Center's survey team.
But the Thai government is not playing down the extent of damage to its marine ecosystems in the Andaman Sea. ''These are initial surveys,'' Minister of Natural Resources and Environment Suwit Khunkitti told reporters.
''About five to 10 percent of the deep water coral reefs have been affected, but some areas have also been wiped out... In the shallow water coral reefs damage has been five to 30 percent. But also some areas have been badly damaged,'' said the minister.
One-third, or 700 km, of the Thai coastline is on the Andaman Sea, which holds half of the country's reefs, the primary source of sustenance for local communities.
Murky water makes it impossible for the coral to absorb the sunlight it needs for survival. Suwit said Thai volunteer and navy divers are trying to save coral reefs covered by sand.
''They are working really fast but need further support,'' said the minister. ''Ten countries have offered to help Thailand in its marine environment rehabilitation program. I think they have to come in very quickly. There’s no time to lose.''
The Phuket chain of islands is most at risk because the coral there are in shallow water.
Any abrupt changes to the coral reef ecology, where 70 percent of marine species in the Andaman Sea are found, would inevitably affect its inhabitants, ''But it’s too early to say by how much,'' Suchnit Deetae, a marine biologist at the Bangkok-based Kasetsart University, told Tierramérica.
In the wake of the devastation caused by the tsunami, Suchnit stressed the importance of environmental databases.
''We're fortunate to have at least one coral map of the Andaman Sea, which gives us the chance to compare the size of reefs before and after the tsunami. But we need more funding in order to do further classification of marine species to better prepare ourselves for disasters, so that we know what’s there in our seas,'' he said.
Meanwhile, the Natural Resources and Environment Ministry has plans to either close off or limit tourist trips to some of the 10 marine national parks in Phuket, Phang Nga and Krabi.
''It is too early to say how long certain sites will remain closed. We must let nature take its course to bring back the beauty that once was there,'' said Suwit.
* Sonny Inbaraj is an IPS editor and correspondent.