Large swathes of abandoned shrimp farms in a coastal lagoon in Sri Lanka's western coast could be returned to its former glory as a mangrove eco-systems if an ambitious plan by a conservation charity succeeds, officials said.

The International Conservation Union (IUCN), a charity, is working with regional authorities in Sri Lanka's Puttalam district to release a part of over 1,100 hectors of abandoned commercial shrimp farms for restoration.

"Earlier there were more than 300 shrimp farms in the Puttalam district," says Shamen Vidanage, who co-ordinates a coastal resource management project for I.

"But now there are only 50 farms."

Disease Stricken

A viral infection called 'white spot disease' which started to spread in the area has destroyed the once profitable business. The disease was believed to have broken out in China in 1993 and spread to other parts of the globe.

Vidanage says the disease is suspected to have come from shrimp larvae imported from Thailand for commercial farms.

"Commercial shrimp farms cultivation started with the support of the government in areas where land was allocated for the activity," says researcher Jayampathy Samarakoon.

"When people realized that this is a profitable activity they started, looking for a land and they encroached that any land was suitable."

"Then they started to cutting down any sort of coastal vegetation."

Sri Lanka has 22 different 'true' mangroves species and several associated plants.

Shrimp farms not only destroy mangroves, but nutrient rich waste that is pumped out promote the growth of algae which block sunlight degrading more of the coastal eco-system and breeding zones of fish and crustaceans.

Eventually it leads to a collapse in fisheries in the broader eco-system. The Puttalam and Mundalam lagoons are some of the most hit by commercial shrimp farming.

Court Backing

The IUCN says it got an order from Sri Lanka's Supreme Court to back it in efforts to restore destroyed mangrove wetland.

"But logistically we need a free access for these farms," says Ranjith Mahindapala, country Representative of IUCN said.

The land, which has been leased by the regional authority, the Western Provincial Council, to private farm owners has to be weaned back. Activists say state land that had mangroves had been leased for nominal fees for up to 30 years.

IUCN wants about 10 acres (2.47 acres is a hectare) of land for a pilot project.

Sri Lanka's mangroves cover only less than 0.01 per cent of the land area in the country or about 12 000 hectares. The area restricted to a narrow belt around estuaries and lagoons of the island’s 1700 kilo meter long coast.

Some mangrove systems are situated close to highly populated towns such as Negambo, Chilaw in the western coast and Galle in the south coast. The largest mangrove area is in the Northwestern coast around the Puttalam lagoon.

Near Puttalam, conservationists say there are now attempts to use hundreds of acres of land to start a saltern. Closer to Sri lanka's capital Colombo - where land is more valuable - mangroves are cut down for other purposes.

"In places like Puttalam people are converting mangrove lands for salt production," says Vidanage.

"People in areas like Negambo (35 kilometres north of Colombo) reclaim mangroves areas for domestic uses like housing and industrial purposes.

Silting

Researchers say mangrove re-planting has to be done carefully to prevent unexpected side effects.

"We don’t have any mangroves growing at the edge of the land facing the sea," says Samarakoon, who has warned against ad hoc planting of mangroves which can increase silting in lagoons.

"Mangroves do not face the sea, but are at the borders of coastal estuaries or lagoon, like that in Puttalam lagoon."

"All the mangroves are inside estuaries or in the margins. So if you are doing mangroves re- planting in the commercial shrimps ponds again we need to think again very carefully."

Shrimp companies built large earth bunds to separate the farms from the lagoon, obstructing the water flow or hydrology.

"When you have those huge bunds it is totally disconnected from the natural system, so easiest ways of restoring it is facilitating the hydrology," says Vidanage.

"You have to break the bunds from certain areas and allow the natural flow to go through the system."

Environmentalists say that a shrimp company had used about 30 truck loads of soil to build an earth bund for a pond covering over one acre of land. The farms were progressively abandoned in the late 1990s.

"Soil eroded the from the farms and gradually filled up parts of the lagoon," recalls Douglas Thisera, a resident from the Southern border of the Puttalam lagoon, who is now a staunch conservationist.

"After filing up soil in these lagoon we have seen algae started to invade the lagoon”

Pilot Study

A pilot project is needed to gauge how best to go about restoring the eco-systems back to its former glory.

"We are proposing to test different activities in restoring the abandoned farms in the pilot project," Vidanage said.

"One is facilitating natural regeneration of mangroves, the other includes low intensive community level farming of aquatic species (milk fish and sea bass) and cultivation of sea weeds."

"The pilot level work it self will not provide a substantial livelihoods benefits. But depending on the results activities can be replicated to benefit more people in the area.

IUCN says to restore a plot of 10 acres of land, about four million rupees is needed or about 400,000 rupees per acre.

The IUCN is now running a project called 'Mangroves for the Future' to improve the livelihoods of villagers living around the Puttalam lagoon and to preserve the remaining mangrove eco-system.

Over 1000 families are attached to the IUCN community development project.

In one initiative the conservation charity has taught villagers to use more efficient wood burning stoves for cooking and not to cut down mangroves from firewood.

"Earlier we cut down mangroves for fire wood," says Malani, a fisherman's wife from Puttalam.

"But after we became a part of this project we understand that the fish catch is reducing because of mangrove destruction. So now we buy commercial firewood. But we do not use as much firewood as before."