Monthly monitoring, follow-ups vital in preventing their growth, expert says
PETALING JAYA: With the ever-changing temperatures and environment, a leading expert has called for more rigorous monitoring and measures to tackle harmful algal blooms (HAB), especially in the mariculture industry.
HAB pose a public health threat when products such as shellfish or finfish are consumed, as well as a threat to the mariculture industry as a whole, Assoc Prof Dr Lim Po Teen of Universiti Malaya’s Institute of Ocean and Earth Sciences said.
This comes after the Fisheries Department temporarily halted the sale of clams and mussels found in waters off Melaka and Port Dickson, which were contaminated by biotoxins earlier this month.
Preliminary findings revealed that the algae population had gone up drastically due to the unusually hot weather, causing the level of biotoxins to increase drastically.
Using the analogy of a fire safety system, which features water sprinklers and fire extinguishers, Lim said a proactive approach is needed to mitigate drawbacks arising from algal blooms.
“We shouldn’t wait until it arises before we take action. Regular monitoring has to be carried out.
“HAB do not just pose a threat to public health but also to the mariculture industry,” he said when contacted.
Lim is the leading HAB researcher in Malaysia and has vast contributions to the research and development of HAB in the country.
He called for HAB monitoring to be done monthly, adding that this would enable early warnings for farmers at mariculture sites.
“Follow-up action should also be taken once instances of HABs are identified so that farmers are better prepared for potential algal bloom events,” he said.
Lim stressed on the need for mariculture industry players to invest in technology and infrastructure enabling early detection of algal blooms.
“We need to find ways to tackle it before it happens.
“While industry players’ focus is on ensuring the best products, they should also make early detection and mitigating algal blooms as part of their priorities.
“Some may have the mindset that HAB may not happen to them. But what if it happens next year or the following year?” he asked.
The environment, he said, is ever changing and that there should be preparations for this.
He pointed out that El Nino years recorded increases in HAB growth, adding that exposure to sunlight and excess nutrients are among factors contributing to the growth of microalgae.
“The increase in temperature also promotes the growth of these microalgae to a certain extent,” he said.
He said agricultural fertilisers or domestically used water, which contain nutrients, also get into estuaries and coastal waters.
“These act as ‘fertilisers’ for the algae,” he said.
When HAB occur in shellfish farming areas, Lim said the shellfish, which are filter feeders, will consume the microalgae and toxins accumulated in them.
This eventually renders them unsafe for consumption.
“For shellfish, we have to stop harvesting them once it is detected with biotoxins.
“Wait until the bloom ends and ensure the toxin levels reach safe levels, which could take weeks or months,” he said, adding that this is the standard procedure globally.
He also warned of the harm in consuming products affected by HAB.“In severe cases, it could result in fatalities and paralysis if one consumes produce with toxins exceeding the safety limit,” he said.
In 2021, the Kelantan Fisheries Department imposed an immediate ban on eating molluscs from Sungai Geting in Tumpat, due to suspected HAB activity.
