Water pollution and extreme temperatures are the possible causes of the lengthened red tide occurrence in the Inner Malampaya Sound in Taytay municipality, according to Palawan provincial agriculturist Dr. Romeo Cabungcal.
Cabungcal said that pollution may come from nearby households in the Sound that are brought into the sea by rainfall or are free-flowing into the sea.
Nutrients found in pollution elements nourish dinoflagellates that have been inactive in the water and cause their population to grow and cause an algal bloom.
“Nagiging active lang [ang mga microorganisms] kapag may mga nutrients na pumupunta [sa dagat]. Say, for example, ang one possibility nito na maybe may mga pollution, coming from mga household. O may ibang mga activity na nagpo-produce ng nutrients para magkaroon ng algal bloom. And another cause niyan is matindi ang init, tapos biglang uulan, isang cause din ‘yan,” he said in an interview Monday.
The Office of the Provincial Agriculturist (OPA) issued a warning on October 13, discouraging the catching, selling, and buying of shells originating from the Inner Malampaya Sound in Taytay town. According to Cabungcal, the advisory is still active as the area has not yet been cleared of red tide.
Red tide is algal bloom wherein dinoflagellates, a species of algae, have higher than usual populations in seawater. This turns the water rust-colored, hence the name. Dinoflagellates carry toxins that are potentially fatal to sea and human life, as they are easily ingested by all forms of sea life.
Two types of poisoning, namely paralytic shellfish poisoning (PSP) and amnesic shellfish poisoning (ASP), can result from ingesting seafood caught in areas with red tide. Fish kills have also been attributed to red tides in other countries with a warmer climate.
Scientists have also attributed pollution to increased populations of dinoflagellates species to warm ocean temperatures, low salinity or salt content in seawaters, and extreme heat suddenly transitioning into heavy rains.