GEORGE TOWN: Streaks of pink have appeared in the sea off Teluk Bahang since the weekend, arousing the curiosity of beachgoers.
As of this afternoon, the pink hue is still visible in some parts.
Local fishermen have expressed concerns and lamented on the death of thousands of fishes as a result of the situation, about 1 km from Muha Head until the coast off Teluk Bahang.
Teluk Bahang Fishermen's Association chairman Johari Mohamad said they came across the streaks of pink about two days ago, with many dead fishes on the surface.
"As a result, the sea condition was also not as nice as always. We are worried if this situation prolongs, more fish may end up dead," he said.
Centre for Marine and Coastal Studies (CEMACS), Universiti Sains Malaysia, director Profesor Datuk Dr Aileen Tan Shau Hwai described the situation as the red tide bloom.
She said a similar incident happened in April during the hot spell (with some rains that brought the nutrients from land to the ocean).
She said the red tide could happen due to localised or coastal pollution and high heat and rain outflows.
"This latest event was first noticed two to three days ago when the bottom dwellers (such as the stingrays and crabs) come up to the surface, most probably due to low oxygen level (anoxia).
"It has also been reported the strong stench of sulphide in the mud," she told the New Straits Times when contacted today.
Tan said, this time around, the red tide bloom was more intense compared to April.
"This is because it happened during neap tide (compared to spring tide in April). Also, the blooms were not drifted away or carried away by the tides or waves," she added.
According to Tan, the variations in environmental factors such as atmospheric temperature associated with high rainfall resulted in changing the sea surface temperature and the availability of dissolved nutrients are responsible for the proliferation of Noctiluca scintillans.
Noctiluca scintillans is a unicellular microorganism that can exist in a green or red form, depending on its pigmentation.
However, blooms of this species can be responsible for environmental hazards, such as fish kills due to clogging of gills or reduction of oxygen levels in the water.
"With the sea getting hotter, more sour and breathless, all this will increase the frequency of the blooms.
"As far as we are concerned, no toxic effects are known. But it is possible that the high ammonia content of the vacuole irritates fish, which generally avoid the bloom areas," she added.
Tan said the cause of fish death is still being investigated.
"The fish are in asphyxiation (deprived of oxygen, resulting in unconsciousness or death or suffocation) state. All fishes are caught with their mouths wide open. The gills are quite clean and don't have a lot of these algae.
"Their stomachs are mostly not filled," she noted.
Meanwhile, Chief Minister Chow Kon Yeow said he has been informed about the matter.
"I will call the state Fisheries Department and the state Department of Environment to get further details.
"We will monitor the situation," he added.