Singapore's only marine station for academic research may have to slash operations by March next year if it does not find a way to foot its mounting bills.

On Monday, lead researchers at the National University of Singapore's Tropical Marine Science Institute (TMSI) received word that the institute's marine laboratory on St John's Island would soon be unable to cover its operating costs.

"We have come to the painful conclusion that it is no longer financially possible or justifiable to continue operations at (St John's Island)," wrote Professor Barry Halliwell, NUS deputy president for research and technology, in an e-mail, which also asked researchers not to accept new projects involving the lab.

Costs have been rising every year, driven by diesel for the lab's generators, boats to and from the island, and security and maintenance, Prof Halliwell told The Straits Times.

"The amount of high-quality research coming out has to be balanced against the cost of operating the facility," he said.

The lab opened in 2002 to study aquaculture, marine biology and other disciplines. It has an operating cost of more than $1.7 million a year, out of a total institute budget of $1.9 million. Besides work done there, TMSI also carries out fresh water, coastal, climate and environmental modelling projects in Kent Ridge, many on behalf of government agencies.

However, NUS does not intend to close down the island lab completely and wants the option to reactivate it if a large grant or project comes along, Prof Halliwell said. It will work with lead researchers to see what can be moved elsewhere and what needs to stay, he added. Forty-eight of TMSI's 140 or so researchers and staff are at that facility.

Projects like the cultivation of giant clams, tests of anti-fouling measures and growth of corals may need to stay for access to clean, running sea water generated by the lab's filtration system.

Besides moving projects back to the mainland, said TMSI director Peter Ng, "every option is on the table" for funding.

These could include an endowment for the institute, donations from the public or corporations, and fees collected from visiting scientists, all of which are used by similar research stations overseas.

One tantalising prospect is the electricity generator on nearby Kias Island, a reclaimed shoal that could supply power to St John's, Pulau Seringat and Lazarus Island, the three linked islands.

Cables were installed in 2006 as part of plans to develop the area for high-end resorts or housing, but those plans are on hold.

Still, it would be expensive to link them to the far corner of St John's where the lab sits, said Professor Ng.

"The station provides opportunities that other places cannot," he added. Scaling down the lab, one of only a handful of such stations in South-east Asia, "is not fatal, but it may send out the wrong signal or close the door to other opportunities".