On the small island of Pulau Ketam lies a facility where baby fish are nursed to withstand the nastiest of diseases. Set up by fish farm Marine Life Aquaculture, the land-based site works like a health clinic.
Its four-finger threadfin fish take 21/2 months to grow to about 10g, at which stage they are given a vaccination jab. It takes about 16 man-hours every day to vaccinate 5,000 fish but the farm's chief operating officer believes it is worth it.
"These fish are very fragile and the mortality rate is usually 80 to 90 per cent but we've managed to turn it around. In our fish, 70 per cent can survive," said Mr Frank Tan.
Before the fish are vaccinated, the eggs and larvae are reared in sterilised water treated with ultraviolet rays, ensuring they do not become vulnerable to aquatic disease.
The vaccination and controlled environment help protect fish stock against common diseases caused by bacteria such as Tenacibaculum maritimum, more commonly known as T. mar, which causes lesions in fish. It also protects them against Streptococcus iniae, a major disease among tropical fish.
Mr Tan, 41, who founded the farm in 2009, said improving his stock's survival rate helps to solve the main "bottleneck" of the aquaculture process. He said: "Imagine if you rear 100 fish but only 10 to 20 survive, how would that ever make your business viable?"
About 8 per cent of fish consumed here are produced locally and the Government hopes to increase this to 15 per cent. To shorten the time needed to raise the fish to marketable size, Mr Tan said his team identifies adult fish which reproduce fast-growing juvenile fish.
Doing so has enabled him to shorten the harvesting time from about 10 months to 61/2 months - reducing the amount spent on food and other operating costs. His 6ha Pulau Ketam site houses nearly 100 tanks. About 200 tonnes of fish are produced each year.
Apart from threadfin, he also grows seabass. Once the fish are about 100 days old, they are transferred to net cages in his Changi fish farm located opposite.
There are about 120 coastal fish farms in Singapore.
An Agri-Food & Veterinary Authority (AVA) spokesman said: "Given Singapore's limited land resources... it is important to intensify agriculture land use, and raise productivity and capability of our farms so we can do more with less."
Earlier this month, the AVA launched a tender for the development of a commercially viable indoor farming system for edible fish.
The tender will close on June 2.