Turning back the tide: growing mangrove forests in Thailand

Bangkok Post 12 Jul 08;

Local efforts to reverse effects of coastal erosion, by growing mangrove forests to overcome flooding, show signs of success, writes Chaiwat Satyaem in Samut Sakhon

Local efforts to save the natural environment and fight coastal erosion in Ban Khok Kham of Samut Sakhon's Muang district are showing signs of success. Until recently, villages were picking up the pieces from severe coastal erosion after greedy businesses invaded the mangrove forests which are natural buffers along the shore.

Local communities hope the experimental Phan Tai Norasingh learning park will help reverse the erosion problem.

Prasarn Iamwijarn, a teacher at Phan Tai Norasingh Witthaya school, is in charge of the learning park project financed by a 10-million-baht budget from the Khok Kham tambon administration organisation.

He said environmental destruction in Muang district was too severe to ignore. Until 1991, shrimp farms were common.

The farms gradually went out of business and the ground was left hard and barren. Poorly-managed farms polluted the water and no measures were put in place to save the environment.

The school was hard hit as it sits on land which was formerly a salt farm.

The school is flooded every year and remains submerged for up to four months at a time.

At the peak of shrimp farming, the area near the school was covered with salty water and no trees could grow.

Mr Prasarn said that in 1996 he found ways to solve the problem by drawing on lessons from royal projects initiated by His Majesty the King.

He launched a project to plant mangrove trees on deserted shrimp farms around the school.

Students collected mangrove pods for cultivation and planted the young trees around the school.

More than 40% of green areas around the school were restored, which Mr Prasarn regards as a big advance.

Mr Prasarn convinced shrimp farmers to recognise the merits of growing mangroves around their farms.

Maintaining a balance in the environment by growing mangrove trees was crucial for the survival of marine life, he said.

"I thought up a model and borrowed unused land near the coastlines for experiments.

"Now we have grown about 400 rai of mangroves in those areas. As a result, marine life is returning to the area where the mangrove forest has grown.

"The forests also trap mud sediment which will help slow coastal erosion," Mr Prasarn said.

The mangroves have slowed the erosion which led to land subsidence and worsened flooding for the school.

His hard work has now paid off with cooperation from local people.

Residents began by building three rows of experimental bamboo walls along the shorelines as a barrier to protect the area against the force of the waves.

The three-month experiment, a joint effort between Chulalongkorn University and local people, showed that the bamboo walls helped trap sediment, allowing soft ground to build up behind them.

The cost of the bamboo wall is 2.5 million baht per kilometre, which is cheaper than most other wave breakers.

Mr Prasarn said he expected the sediment build-up would allow mangrove planting areas to expand in the next three to five years.

Narin Bunruam, 71, said the project was useful, so he decided to pitch in.

"I think it is important to plant more mangrove forests, which can act as a home to various forms of marine life.

"Most importantly, I believe mangrove forests can help reduce global warming," Mr Narin said.

He said the community has also launched a separate project to breed crabs.

Breeding pens for crabs are put up about one kilometre from shore, using bamboo sticks planted in the sea.

When crabs with eggs are caught, they are not sold straight away, but are kept in the pens until the eggs hatch.

The crabs, without the eggs, are then sold.

The project has caught on with local fishermen and has become a success as crabs in the wild in Khok Kham village are increasing in number.

Even though a crab can lay up to 500,000 eggs, only 10% of them survive.

Mr Narin urged people to stop eating crab eggs so more crabs will be available for consumption in the long term