A natural, low-tech solution to tsunamis: mangroves
The coastal trees and shrubs saved hundreds of lives in India by protecting villages from the waves.
As nations around the Indian Ocean discuss plans for a tsunami early-warning system, environmental scientists here point to an existent, natural form of disaster minimization: mangrove forests.
The coastal trees and shrubs saved the lives of hundreds of people last month, and could save thousands more in the future if further cultivated.
Mangroves form a natural barrier between villages and the roiling sea, and could offer a reliable backup to any new international effort to coordinate warnings and draw up evacuation procedures.
"For thousands of years, mangrove forests have provided a natural buffer against cyclones and other storms that often hit the shores of southern India," says V. Selvum, project director of the MS Swaminathan Research Foundation in Madras (Chennai).
Mr. Selvum says that 172 families were saved from the tsunami in the fishing village of Thirunal Thoppu in India's Tamil Nadu state only because the mangroves are thriving and dense there. He also mentions three other Tamil Nadu villages where damage had been minimized by the aquatic trees.
"Every village has more than 100 families, so just think of the number of lives saved," he says.
One recent CNN story told of a baby boy in Thailand who was saved by the mangroves when the water rushed in and out destroying everything else in its wake.
"Even though the mechanical impact of a tsunami is enormous, and is bound to destroy the first line of mangroves, the water suddenly slows down as it moves farther in," Selvum says.
For the last 70 years mangroves, which are abundant at river mouths, have been severely depleted as villagers chop them down for fuel and fodder. The dried up areas then absorbed sea water, which in turn increased the soil's salinity and destroyed other vegetation.
The MS Swaminathan Research Foundation has found a way to reverse this problem by channeling the sea water out and bringing the fresh water in. The foundation, which began 14 years ago, works to conserve and regenerate coastal mangroves along India's eastern shores as well as transfer salt-tolerant genes from the mangroves to selected crops grown on the coast.
Recognizing their work, the Indian government began a joint Mangrove Management Project in the 1990s, in local communities all along the east coast from Tamil Nadu to West Bengal in seven mangrove ecosystems.