BANGKOK, 7 August 2008 (IRIN) - Panya Changcharoen still remembers when he was a child and the Bang Khunthian District stone, marking the edge of Bangkok, was in a lush mangrove forest. Now, at 60, he finds it hard to believe the shore has eroded so much that the marker lies stranded far out in the muddy sea.

"All the mangrove forests are gone and coastal erosion keeps getting worse, especially during the monsoon season," Panya told IRIN. "I'm not sure how long my family and I can live here," he said. "We desperately need help …before we lose the whole district to the sea."

Bang Khunthian, Bangkok's only seaside district, once comprised 5km of muddy coastline and was home to abundant mangrove forests. For hundreds of years, they housed rare and diverse species of plants and marine life.

However, more than 3,000 rai (483 hectares) of mangrove forests have been lost to the sea over the past 30 years. Panya, a former village head and one of 127 families who own seaside land, said most of their plots had washed away.

The explosive growth of factories and industry in the area has been a catastrophe because seashore ground is soft. Too many factories pumping ground water made the land around Bang Khunthian district subside, according to environmental specialists. Commercial development and housing projects also contributed to a loss of mangrove forests. When natural buffers vanished, the district's coastline rapidly became submerged in seawater.

According to the Department of Marine and Coastal Resources, Thailand loses about 5-20m of shore each year along its 2,677km coast. The country now has only 1.04 million rai (167,741ha), down from over two million rai (322,580ha) in 1961.

Saving seashore districts such as Bang Khunthian is crucial to Bangkok since the area is the capital's first line of defence against rising sea levels. If the trend continues, the city will be more vulnerable to flooding and seawater contamination. As a result, local residents will be at risk, particularly those who depend on fishing and shrimp farming.

Different coastal protection structures such as jetties, groins, breakwaters and sea walls have been used to combat severe erosion in coastal provinces that face the Gulf of Thailand, including Samut Prakan, Rayong Prachuap, Khiri Khan and Songkhla.

However, some structures could harm local livelihoods.

About 30km northeast of Bang Khunthian district is Khun Samut Chin village. This small seashore town in Samut Prakan Province is also facing land erosion, with many electricity poles along the coastline stranded far out to sea.

Sausage-shaped sandbags, designed by the marine department, are to be placed offshore to test their effectiveness in stemming the tide. In Samut Songkram Province they helped slow down the erosion and dissipate the powerful sea waves, while at the same time trapping sediment behind the groins to form a foundation for mangrove forest growth.

Locals oppose sandbags

But Samon Khengsamut, head of Khun Samut Chin village, said she and more than 400 local residents opposed such sandbags because they would block marine life from breeding, undermining the earnings of villagers who collect crabs and seashells for sale.

The village wants concrete poles built as a barrier along the shoreline to minimise the sea waves and trap soil behind the concrete wall. When the soil becomes thick enough, young mangrove trees will be planted there as a breeding ground for marine populations, Samon said.

"The authorities need to listen to the particular plight of each community and adopt solutions that are best suited for individual coastal areas," she added.

Constructing dykes in coastal areas of Bangkok and neighbouring provinces and replanting mangrove forests could temporarily improve the coastal environment and stop shoreline erosion, Anon Snidvongs, director of the Southeast Asian regional centre of START (Global Change System for Analysis, Research and Training http://www.start.org/), which conducts research and training on climate change.

"The city must invest in stopping coastal erosion," Anon said. "If mangrove forest encroachment continues, the land will sooner or later be washed into the sea," he said.

Long-term solutions to coastal erosion and disaster preparedness are needed, Anon said. "The most important thing is to promote public awareness of the problem. Villagers living near the mangroves must realise that only by radical conservation efforts will they sustain their ways of life."

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