Rescued corals thrive on sea walls

Audrey Tan, The Straits Times AsiaOne 13 Jan 17;

The sea walls around one of Singapore's Southern Islands are now thriving with marine life - life that would otherwise have been snuffed out by works to build a new port in Tuas four years ago.

Of the 213 corals that were grown in nurseries and then transplanted onto sea walls on Lazarus Island, south of the mainland, scientists recorded a survival rate of more than 90 per cent.

The corals lying in the path of port development works were given a second lease of life, after the Maritime and Port Authority of Singapore (MPA) took steps to save them.

In 2013, the agency engaged marine biologists from the National University of Singapore's Tropical Marine Science Institute (TMSI) to collect small coral fragments from Sultan Shoal, located south of Tuas, to be grown in nurseries.

Each barely the length of a human finger, the hope was to nurse the fragments into larger, fist-size colonies that could be used to rehabilitate reefs. It was a novel method that proved successful.

The findings were published last November in the science journal Ecological Engineering.

The method also helped improve the coral cover at the three transplant sites on Lazarus Island. One of the sites saw hard coral cover increase from 3 to 20 per cent.

The results were encouraging, as it showed that man-made structures, such as sea walls, could be conducive for marine life, reducing the impact of coastal development and loss of marine biodiversity, said Dr Toh Tai Chong, a research fellow at TMSI who led the project.

Healthy coral reefs are important as they not only draw marine life, but are also effective buffers against strong waves and can help filter pollutants from the water, said coral expert Chou Loke Ming, who supervised the project.

The transplant sites were selected for their similarities to the source site at Sultan Shoal, in terms of water temperature, underwater currents and level of sedimentation in the waters. This ensured they were conducive to coral growth in the first place, said Dr Toh.

The coral nursery project is just one of the initiatives funded by MPA to save marine life in the way of the Tuas port development.

Between September 2013 and August 2014, MPA also relocated more than 2,000 coral colonies from Sultan Shoal to the waters off St John's Island and Sisters' Islands.

About 50 volunteers helped out in activities such as harvesting coral fragments and transplantation.

For the coral nursery project, the inclusion of volunteers in fieldwork and data analyses could help lower the cost of the project by up to 23 per cent, Dr Toh noted.

He said: "The savings in manpower expenses can reduce the high costs of rehabilitation projects and could encourage companies to undertake such efforts. More importantly, the engagement of volunteers promotes environmental awareness and stewardship."

An MPA spokesman said: "MPA has always believed that while developing our ports to meet future demands, environmental protection should not be compromised and MPA would adopt a similar approach for our future projects."