Climate change has been portrayed as the distant concern of activists in developed countries which can “afford” to be bothered about such “greenie” issues. But the bad news is: global warming is already affecting us in Malaysia too. For one, it may hit the seafood that many of us love feasting on.

We are lucky that seafood is still relatively affordable and easy to find. But this may not continue, due to something commonly known as the Red Tide, or what scientists would prefer to call harmful algal blooms (HABs).

HABs, comprising phyto-planktons or microalgae, are already in the sea. But as temperatures rise, the warmer waters make them start to “bloom” and multiply. This causes the whole surface of the ocean to become red (or green, orange or purple) due to the algae’s pigments.

Pollution makes matters worse. Excess fertilisers from plantations, animal waste from farms or food waste from humans cause waters to become more “nutrient-rich” and further speed up algal blooms.

“These algae produce toxins. In low amounts, it doesn’t matter, but when they bloom, the shellfish (that we eat) will have so much toxin in them,” said Prof Dr Phang Siew Moi, director of the Institute of Ocean and Earth Sciences (IOES) at Universiti Malaya, Kuala Lumpur, during a seminar on Air-Ocean-Land Interactions last month.

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Plankton sampling activities at an aquaculture site by IOES researchers.

IOES scientist Assoc Prof Dr Lim Po Teen said that the toxins found vary from one type of algae to another.

Some may just cause numbness of the lips. But other algal toxins may have a more devastating paralytic effect so that even our lungs stop moving – and we will need emergency resuscitation to avoid death, noted Lim.

Baleful Blooms

These toxins don’t just affect us, they can also cause fish’s gill cells to break down, thus damaging our fishing industry.

Others may make us forget where we live as we are returning from the seafood restaurant!

“There is also something called amnesic shellfish poisoning (ASP) which causes short term memory loss,” explained Lim.

Algal blooms can cause serious damage and have been reported hitting other countries. In the United States, between 2015-2016, Lim noted that many marine mammals and birds suffered from ASP, with the scale of the bloom stretching all the way from California to Alaska.

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An algal bloom at a lake in Hefei, Anhui, eastern China. Algal blooms in many Chinese freshwater lakes are chiefly caused by untreated sewage containing high concentrations of nitrogen, a main ingredient in detergents and fertilisers. Photo: AFP

Looking into the news archives, there is news that algal blooms have also wreaked havoc off New York in 2015 (creating a zone of “dead water” without oxygen) and at Florida in 2016 (where beaches had to be closed to tourists).

In China, it badly affected the sea at Qingdao in Shandong province in July 2008, just a month before the Olympic sailing event was to be held there. Soldiers had to be brought in to manually scoop out the algae.

“We started working on ASP and related organisms five years ago,” said Lim.

“These species are very common in our waters but the good news is, very few species are toxic. But that doesn’t mean we should stop monitoring and research.

“We also found that this group of organisms is very diverse. Eight new species from Malaysian waters alone have been discovered out of the 43 globally known species in the world,” he explained, adding that the eight species fall under moderately toxic and non-toxic categories.

But even blooms of non-toxic species can harm marine ecosystems. When huge amounts of algae die and decompose, the process can deplete oxygen in the water, causing animals to either leave the area or die.

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Assoc Prof Lim says that amnesic shellfish poisoning (ASP) causes short term memory loss. Photo: The Star/Azman Ghani

Based on past records, before the 1990s in Malaysia, all cases of HABs were found in Sabah alone. However, since then, cases have been recorded in Johor, Penang and along the east coast of Peninsular Malaysia.

When detected, the Fisheries Department will announce a “Red Tide” situation, and fishermen must stop collecting shellfish.

IOES works with the department to monitor plankton and toxin levels, and also trains their staff to do monitoring work.

“The most pressing issue is of course public health and how to ensure food safety,” underlined Lim. “At the same time, we try to reduce the impact on aquaculture because the industry is commercially important. A negative impact can cause millions in losses.

“We also want to find out why they bloom and control it, instead of just giving warnings,” he added.

One method is to “bio-remediate” small affected areas, or to clean up using naturally-occurring or specially introduced microorganisms to conteract the algal blooms.

But Lim warned, “If it’s a big area, like the Gulf of Thailand for example, it will be very difficult to clean up.”

To find out how global warming causes stronger hurricanes and floods, click here.