For a bio-shield

Casting his net to catch small fish and prawns in the Pichavaram lake in Tamil Nadu. In the background is the mangrove forests. - GAUTAM SINGH/AP

FOREMOST among the issues thrown up by the December 26 tragedy is the need for a tsunami warning system and a permanent protective shield along the coast to minimise the loss of lives and property in the event of a future killer wave attack. Tamil Nadu Chief Minister Jayalalithaa, during her discussion with Prime Minister Manmohan Singh in Chennai on January 7, stressed the "absolute importance" of putting in place a tsunami warning system. The Prime Minister indicated that her request would be given the highest priority. In order to provide a protective shield to the people living on the coast, the Chief Minister made a special request for funds to construct a sea wall along the 1,000-km Tamil Nadu coastline. A government press release said that "the Prime Minister had indicated that the World Bank and other agencies would be approached to take up the sea wall programme".

A cross-section of people, including fishermen, agriculturists, political leaders and activists working in the fields of environment and coastal safeguards, gave divergent views on the way the coast can be protected (story on CRZ on page 133). The majority view is in favour of a natural fence of mangroves and other trees in preference to a concrete or stone structure. Many of them pointed out the "failure" of the stone walls raised along the coast of North Chennai to provide any effective resistance to even cyclones. On the other hand, they said, the trees and shrubs along the coast had saved the lives of hundreds of people in some places.

Several people said that mangrove forests had provided a natural shield against cyclones. Environmental experts are also of the opinion that mangroves that formed a natural buffer between land and sea could prove a dependable cover against the ravages of nature. At present, only about 10 per cent of the State's coastline enjoys the protection of mangroves.

For instance, the Pichavaram mangrove forest, a tourist attraction in Cuddalore district, protected about 6,000 people living in six hamlets - T.S. Pettai, Vadakku Pichavaram, Therkku Pichavaram, Meenavar Colony, MGR Nagar and Kalaignar Nagar - from the tsunami attack, according to the Chennai-based M.S. Swaminathan Research Foundation (MSSRF). These hamlets are located between 100 metres and one kilometre from the mangroves. Seawater did not enter the village and hence there was no loss of property.

However, four women belonging to MGR Nagar, who were near the shore, were caught in the waves. A local resident is quoted by the MSSRF as saying, "We saved the mangroves by restoring them and it saved our life and property."

A Nagappattinam-based social activist, Jesu Rethinam, said that the Vedaranyam mangrove forests had protected the people of Muthuppettai and Thillai Valagam. Jesu Rethinam, who has been working among the coastal people for well over 15 years, said that the general opinion among the fishermen was that a sea wall would be a hindrance to the movement of boats. Another argument against the construction of a sea wall is that its cost is too prohibitive and there is no guarantee that the wall would withstand the force of the tsunami wave.

Suggesting, among other things, the strengthening of environmental defence systems as a long-term post-tsunami programme, the agricultural scientist M.S. Swaminathan has called for steps to initiate a coastal bio-shield movement. In the article, "Beyond tsunami: An agenda for action" (The Hindu, January 17), he says: "This involves the raising of mangrove forests, plantations of casuarina, salicornia, laucaena, atriplex, palms, bamboo and other tree species, and halophytes that can grow near the sea. These will serve as speed-breakers under conditions of coastal storms, cyclones, and tsunami. In addition, they will serve as carbon sinks, since they will help enhance carbon sequestration and thus contribute to reducing the growing imbalance between carbon emissions and absorption."

"Mangroves," Swaminathan continues, "are very efficient in carbon sequestration. They also promote sustainable fisheries by releasing nutrients in the water. Further, they will provide additional income and make coastal communities eligible for carbon credit." In his opinion, the bio-shield movement will confer multiple benefits to the local communities as well as to the country as a whole.

A seasoned agriculturist, Moosa of Chidambaram, expressed the apprehension that a sea wall would prevent rainwater run off into the sea. "This will lead to the flooding of agricultural land. The land will also be degraded owing to stagnation of water," he said.

The other alternatives to the sea wall include hook-shaped jetties at suitable places, which traditional fishermen in Tuticorin, who depend on manually operated craft and gear, have found useful. Experts and fishermen endorse this view.

Eminent marine scientist Patterson Edward has suggested a community-based strategy to protect the coral cover along the Tuticorin coast. Scientists and experts have suggested that the government approach the problem with an open mind and evolve a multiple-system strategy to suit the varying conditions of the different coastal regions.