The plankton bloom behind the recent mass deaths of fish along the Johor Strait is likely to keep happening.
And this will pose a "real challenge for long-term fish farming in that area", said Minister for the Environment and Water Resources Vivian Balakrishnan yesterday.
"The Agri-Food and Veterinary Authority and the fish farmers are going to have to sit down to discuss what's the best way forward."
Two Saturdays ago, coastal farms in Changi lost thousands of fish to plankton bloom. Then last Friday, farms in Lim Chu Kang were hit. More than 500 tonnes of fish have been lost.
Asked about the issue yesterday, on the sidelines of the Green Corridor Run, Dr Balakrishnan said that plankton blooms tend to occur whenever there is a dry spell or drought.
This is especially true for the waters facing the Strait of Johor.
"This is likely to be a recurrent problem with global warming, with greater incidence of both droughts as well as heavy, intense storms," he added.
Plankton blooms can be deadly as the plankton suck oxygen from the water, suffocating other marine life.
The National Environment Agency said that the first half of this month is expected to have less rainfall than usual. This follows significantly low levels of rain in the previous two months.
The dry weather is partly due to the early onset of the north-east monsoon's dry phase, which is characterised by drier weather and occasional wind.
Last Saturday, dead fish, including catfish and mullet, were found washed up on the shores at Lim Chu Kang jetty, resulting in a clean-up operation by the National Environment Agency which continued until yesterday.
It is believed that more than 200 bags of dead fish were collected at the jetty.
Across the Causeway, Malaysian reports estimated that six tonnes of wild and cultured fish were found dead in areas such as Johor Port and Puteri Harbour.
The AVA said last week that it will provide assistance to fish farmers affected by the fish deaths, so that they can recover and restart their operations. There are 117 coastal farms around Singapore.
It is also looking to enhance their ability to better withstand such incidents - for instance, by putting in place contingency plans.
Fish farmer Simon Ho, who is in his 60s, hopes for a longer- term solution to prevent the mass fish deaths from happening again.
The plankton bloom wiped out all 80,000 of his silver pomfrets this year.
When the bloom hit last year, he managed to save half of his stock.
"I'm not going to start rearing fish again until there's a solution to the plankton problem," said Mr Ho, who owns New Ocean Fish Farm.
"We've tried so hard already."