NParks to conduct coastal protection and restoration works at Pulau Tekong

Channel NewsAsia 11 May 10;

SINGAPORE: It is the largest of Singapore's outlying islands and is used exclusively for army training.

Now, more than 1,000 mangrove trees on the north-eastern coastline of Pulau Tekong are at risk of falling due to coastal erosion.

To protect the coast and mangroves in the area, the National Parks Board (NParks) will be conducting, for the first time, coastal protection and restoration works at the north-eastern coastline of Pulau Tekong.

Deputy director of NParks' National Biodiversity Centre, Dr Lena Chan, said that the erosion - with mud being scraped out - is due to movements of ships and strong waves in the area.

The erosion has affected 3km of north-eastern shore, posing a threat to the 92 hectares of mangroves in Pulau Tekong which is one of the largest remaining mangrove areas in Singapore with a mature and undisturbed habitat.

From a study it commissioned in 2006, NParks found that 1.65km of the north-eastern shore is most severely affected.

At some points, the extent of the erosion was as deep as 1.2 metres below the level of the mangrove berm.

NParks' works will concentrate on restoring this 1.65km stretch.

"The coastline is very precious to us. It is important that we make sure it is not seriously eroded and we have good mangroves right next to the coastline," said Dr Chan.

The first stage in the restoration process will be to fill the eroded parts below the mangrove berm with mud-filled biodegradable sacks.

Next, loosely-placed stones will be placed in front of the berm as a shoreline stablisation measure.

Around 8,000 mangrove saplings will be planted in front of the stones to help deflect the waves.

The saplings will also serve to increase the biodiversity of the mangroves population on Pulau Tekong.

As a further anti-erosion measure, two rows of bakau (a type of mangrove tree) poles will be set up in front of the saplings to be the "front battle line" to further reduce the effect of the waves, said Dr Chan.

A tender will be called in June for the work and NParks expects the project to be completed by June next year.

MediaCorp understands that the works on the north-eastern shore will not affect army training on Pulau Tekong as training is not conducted there.

- CNA/jy

Saving Tekong's coastal greenery
NParks' pilot project to stem erosion of mangroves by waves from passing vessels
Grace Chua Straits Times 12 May 10;

THE north-east coast of Pulau Tekong is being swept away by the sea, and taking a stretch of pristine mangroves with it.

To stem the erosion, the National Parks Board (NParks) is planting more mangroves in a pilot project on the military island off Singapore's east coast. And if it succeeds, the same methods could be used in other threatened coastal areas here.

Click on image for larger view.

The 92ha, 3km-long stretch of mangrove swamp is home to rare birds and mangrove trees. But strong waves from passing vessels have scooped out chunks of the coast to form horizontal berms (see graphic) held in place only by the mangrove roots. In 2006, NParks found that a number of trees had fallen along a 1.65km stretch of coastline. Another 1,300 were in danger of toppling.

It began collecting data on the site, and in February last year started work on modelling the area's wave movements and investigating the soil.

With development consultants Surbana, NParks designed a set-up of mud-filled bags, rocks, mangrove seedlings and poles to not only replace lost mangroves but also stop repeat erosion. NParks also plans to plant certain hardier species of mangroves farther out to sea to stymie the waves.

In their assessment, environmental consultants DHI assured that the project would not cause the coastline to creep outwards towards international boundaries, and there would be no cross-border physical or ecological impact. The site is just 760m from the Singapore-Malaysia boundary.

Construction is expected to begin in the middle of this year and take about 12 months. The same methods may one day be applied to other eroded areas like Sungei Buloh near Kranji.

'We hope this will be a good test-bedding site, though conditions might be different at different areas. But this is a good model for areas that have mangroves and are eroded,' said NParks' National Biodiversity Centre deputy director Lena Chan.

Even though the Tekong mangrove area is off-limits to the public, it remains an important part of Singapore's natural heritage and a source of genetic diversity, reminded Dr Chan.

National Institute of Education plant biochemist and mangrove expert Jean Yong said it was important to plant multiple tree species on such engineered structures to boost biodiversity.

The public can view the project's environmental impact assessment report till next month - by appointment with NParks - when a tender for the project will be put up.

Taking on the Pulau Tekong threat
Project to contain erosion to be completed in a year
Ong Dai Lin, Today Online 12 May 10;

IT IS the largest of Singapore's outlying islands and is used exclusively for military training. Now, coastal erosion is threatening more than 1,000 mangrove trees on the north-eastern coastline of Pulau Tekong. To protect this natural habitat, the National Parks Board (NParks) will for the first time be conducting coastal protection and restoration work in the area.

Deputy director of NParks' National Biodiversity Centre, Dr Lena Chan, said that the erosion - with mud being scraped out - is due to the movement of ships and strong waves in the area.

The erosion has affected 3km of the north-eastern shore, posing a threat to the 92 hectares of mangroves in Pulau Tekong which is one of the largest remaining mangrove areas in Singapore with a mature and undisturbed habitat.

From a study it commissioned in 2006, NParks found that 1.65km of the north-eastern shore is most severely affected. At some points, the extent of the erosion was as deep as 1.2 metres below the level of the mangrove berm.

NParks' work will concentrate on restoring this 1.65km stretch.

"The coastline is very precious to us. It is important that we make sure it is not seriously eroded and we have good mangroves right next to the coastline," said Dr Chan.

The first stage in the restoration process will be to fill the eroded parts below the mangrove berm with mud-filled biodegradable sacks. Next, loosely-placed stones will be set in front of the berm to stabilise the shoreline.

Around 8,000 mangrove saplings will be planted in front of the stones to help deflect the waves. The saplings will also serve to increase the biodiversity of the mangrove population.

As a further anti-erosion measure, two rows of bakau (a type of mangrove tree) poles will be set up in front of the saplings to be the "front battle line" to further reduce the effect of the waves, said Dr Chan.

NParks expects the project to be completed by June next year.

MediaCorp understands that the work on the north-eastern shore will not affect army training on Pulau Tekong as training is not conducted there.

NParks is also studying the extent of coastal erosion at East Coast Park and the Sungei Buloh Wetland Reserve.