Minister for National Development Khaw Boon Wan has said the ministry and the Agri-Food and Veterinary Authority (AVA) "will do our utmost to help our farmers" who were hit by mass fish deaths at coastal fish farms this month.

Thousands of fish, both food fish and wild species, have died over the last week, most likely due to dry weather and neap tides combining to lower the dissolved oxygen in water near the farms.

Mr Khaw wrote in a blog post on Wednesday night: "This is every fish farmer's fear and I feel sorry for their plight - not only is their livelihood impacted, it must be very painful to see their prized stocks wiped out suddenly.

"AVA has been working closely with the farmers to try and salvage the situation since last weekend. AVA/CEO Ms Tan Poh Hong, who spent an afternoon at the farms yesterday, told me that the situation was serious."

At least 39 farms in both the East and West Johor Straits have been affected, particularly those rearing delicate species like grouper, threadfin and golden trevally.

Some farmers had lost their entire stocks, Mr Khaw wrote.

"We had immediately sent in more workers to deploy aeration systems to help normalise the water conditions and also to assist in the disposal of dead fish.

"I have asked MND and AVA to continue to help our farmers and look into their requests to see how best we can help them in the current situation.

"While we cannot control the tide and what nature has in store for us, we will extend a helping hand, wherever possible, to help those affected ride out this rough patch," he added.

Singapore's farms produce roughly 8 per cent of fish consumed here, and the Government had aimed to push that to 15 per cent by 2015.