Plankton bloom monitored by AVA

Straits Times Forum 11 Jan 10;

I REFER to the letters, 'Set up body to handle food crises' (last Tuesday) by Mr Liu Fook Thim, and 'A wake-up call for Singapore' (last Friday) by Mr Winston Lee.

Plankton blooms can happen very quickly if the conditions are right. For example, a combination of factors like sudden shifts in the weather between bouts of sunshine and heavy rain; nutrients from the land washed into the sea by the rain; and little water exchange from rising and ebbing tides.

While the Agri-Food and Veterinary Authority (AVA) already has in place a programme to monitor the water quality in coastal fish farming areas regularly, there are currently no foolproof methods that can accurately predict an impending bloom.

The monitoring programme has to be complemented by good aquaculture practices, including preventive measures to minimise fish kills during incidents of plankton bloom. Such practices include avoiding overstocking of netcages under normal situations, and, in the event of a bloom, the capacity to lower stocking densities even further and having aerators and pumps to disperse the plankton bloom and increase oxygen in the water.

In the recent case of plankton bloom, AVA was alerted about fish deaths in the Pasir Ris Beach area on Dec 26. Investigations were conducted immediately and fish farmers were quickly advised on mitigation measures for plankton bloom. AVA officers were also at the farms daily to monitor water conditions and give technical advice to the farmers.

AVA will continue to work with experts and agencies to develop an early alert system that is tailored to local conditions to strengthen our monitoring system. We will also work with the farmers to strengthen their contingency plans, such as putting in place appropriate aeration systems to prepare for similar situations.

Goh Shih Yong
Assistant Director, Corporate Communications
for Chief Executive Officer
Agri-Food and Veterinary Authority
Ministry of National Development