Commercial farmers are turning swamps in Kuala Selangor, 90 km (56 miles) north-west of the capital, Kuala Lumpur, into shrimp farms and threatening a delicate ecosystem that is home to hundreds of species, environmentalists say.

Wood and marine products from the swamps provide a source of income for villagers and the swamps themselves form a natural protective buffer against rough seas or tsunamis, like the one that struck parts of peninsular Malaysia last December.

"Directly and indirectly, the mangrove swamp has, for thousands of years, protected us in one form or another," said Andrew Sebastian, parks director of conservation group Malaysian Nature Society (MNS).

"The tsunami has shown how important the mangrove swamps are for the ecosystem and our lives."

The swamps shielded several Indonesian islands and Malaysia's northwest coastline from the worst effects of the tsunami, prompting Malaysian Prime Minister Abdullah Ahmad Badawi to call for their preservation. "Mangroves should not be touched, they act as a barrier for big waves...they break the waves," Abdullah said.

SWAMP TO FARM

But despite Abdullah's directive, an 8-km (5-mile) stretch of mangrove forest was turned into a shrimp farm in Kuala Selangor early this year.

MNS, which runs a park to the north of the stretch, is puzzled about the location of the shrimp farm, because it says considerable investment is required to neutralise the acidic mangrove swamp water to sustain marine life.

"Projects like this, if not well thought out, offer only short-term benefits and at the end, will come back and haunt us in terms of the environment, economy and tourism," said Sebastian.

"These companies should heed the prime minister's call and move their operations to a more suitable area."

Mangroves have luxuriant and complicated root systems that combat soil erosion by helping to bind the shore together, forming a shield against destructive waves and sustaining a varied ecosystem that is home to insects, fish and otters.

Blue and orange fiddler crabs scuttle sideways across the swamp in Kuala Selangor along with mud skippers and snails while silver-leaf monkeys swing from the branches of trees through which flit 156 varieties of birds.

Forestry Department statistics show that peninsular Malaysia had 85,800 hectares (214,500 acres) of mangrove swamp forests in 2003, down from 86,497 hectares in 2002.

Villager Hassan Yatim grumbled about the shrimp farms.

"We can't look for snails and other things here. We used to get about 30 kg (66 lb) previously but now there is none. We just scrounge around for what is left here," Hassan said as he gathered mangrove tree poles for his vegetable plot.

ECOSYSTEM BREAKDOWN

The shrimp farms have also changed the lifestyle and diet of animals in the Kuala Selangor swamp.

Kingfishers, shrikes and waders now head for the farms for easy pickings instead of hunting their prey in the thick mangrove forest within the 200-hectare nature park, Sebastian said.

Sleek otters also head straight for the shrimp farms, particularly when farm workers distribute feed to the shrimp.

"To make matters worse, the owners of the farm have put nets along the boundaries which trap the birds and the otters, which are left in the snares," Sebastian added.

Despite the threat to the ecosystem, the Forestry Department says the farms are legal as part of the Kuala Selangor swamps are now classified as agricultural land rather than the forest reserve they were formerly.

Authorities are encouraging aquaculture, by putting fish ponds and shrimp farms in rice fields and mangrove swamps, to boost food production for both domestic and foreign markets. But a shrimp farm set in 400 hectares (988 acres) of rice fields in the northern state of Kedah failed in 2002 after a virus wiped out its tiger prawns, a much sought-after delicacy.