by PRIME SARMIENTO

SO WE may not be as avid seafood-eaters as the Okinawans. But we live in an archipelago bordered by the South China and Celebes seas and the Pacific Ocean, after all, so seafood is part and parcel of our daily lives. The Philippines is among the world’s biggest fish producers, netting over four million tons in 2006. It is also a major fish exporter, hauling in over $500 million annual export revenue. The fishery industry employs nearly two million people and is among the main drivers of the country’s steady agricultural growth.

	FISH is the number one source of protein of Filipinos. [photo by Jaileen Jimeno]

Fish is our number one source of protein and, next only to rice, fish and other marine-based products like clams, seaweed, and prawns are the food we eat most often. Actually, we love seafood so much, we can no longer count the ways we enjoy eating what we harvest from the sea. We have fried tinapa paired with fresh tomatoes and garlicky sinangag (fried rice) for breakfast, sinigang na hipon or bangus (shrimps or milkfish in sour broth) for lunch, and steamed crabs for dinner. There are the reliable fish balls and prawn crackers for snacks, and perhaps even a sardine or tuna sandwich for those who have to have something heavier in between meals. When we drink with our friends, among the pulutan (bar chow) could be baked tahong (clams) and grilled tilapia.

Many of us, however, may lose their appetite for seafood if they knew what is also in the waters from which those good eats come. Says the Environmental Management Bureau (EMB) in its National Water Quality Report for 2001 to 2005: “(Most) surface and coastal waters are under severe environmental stress from point sources of pollution. Human settlements, farming, and industry all contribute to pollution of water bodies.”

Still, it’s domestic wastewater discharges that account for a larger number of bacteria and viruses that pollute our water bodies, according to the Bureau, and independent environmental consultant Joel Adriano agrees.

“We are one of the worst countries (in the world) when it comes to drainage systems,” he says. “Most of our untreated household wastes go to our rivers and seas. These wastes have nutrients that cause harmful algal bloom.” Which is to say, whatever we are flushing down the toilet will soon be swimming with fish and other water creatures, and can eventually lead to red tide, among other things.

The Philippine Environment Monitor for 2006 issued by the World Bank says only seven cities (including Manila) in the Philippines have pipe sewer systems. This means 95 percent of the wastewater flowing from households directly or via septic tanks is transported into groundwater or into public canals and drainage systems. This untreated wastewater eventually flows into (and pollutes) the country’s rivers, coasts, and other water bodies.

OCEANS ARE home to numerous species of single celled organisms such as algae and dinoflagellates. The presence of high nutrients and light levels in the water usually spur these organisms to reproduce rapidly, creating a “bloom.” We have come to know the bloom as “red tide” because some algae grow very fast and form dense, visible patches near the surface of the water, which at times appear reddish orange.

Not all algal blooms are harmful, but there are organisms that produce neurotoxins, which can hurt and even kill higher forms of life such as zooplankton, shellfish, and fish. It can also be fatal to humans who consume what have become essentially toxic fish and shellfish, and they fall victim to paralytic shellfish poisoning. The symptoms include tingling, numbness, and burning of the perioral region, giddiness, drowsiness, fever, rash, and staggering. The most severe cases result in respiratory arrest within 24 hours of consumption of the toxic shellfish.

Bureau of Fisheries and Aquatic Resources (BFAR) Director Malcolm Sarmiento clarifies that fish harvested from red tide areas can be safe to eat if it is cleaned and cooked properly, with all the internal organs — especially the intestine — taken out. But it’s another story with bivalves such as oysters, clams, scallops, and mussels. Shellfish are filter-feeders and ingest the toxin (called saxitoxin) in red tide organism and accumulate the toxin in their internal organs. Cooking and cleaning the shellfish won't help as the heat won't destroy the toxin.

In the Philippines, the first — and one of the country's worst — recorded case of harmful algal bloom or red tide occurred in 1983 at the Maqueda and Villareal Bays in Western Samar. The incident resulted in 157 cases of paralytic shellfish poisoning, of which there were nine deaths. Then the red tide quickly spread to other coastal areas including Carigara, Leyte, Capiz, Sorsogon, and Mati, Davao Oriental.

The final tally of paralytic shellfish poisoning cases for 1983 was 279, with 23 deaths. For the next two decades, red tide would continue to occur in various coastal areas in the Philippines — from Manila to Zambales, to Zamboanga del Sur to Palawan — leading to several outbreaks of paralytic shellfish poisoning. The annual tally of people falling ill because of red tide poisoning ranged from 200 to 300. In 1988 alone, as much as 307 cases were recorded.

Since the late 1990s, however, incidences of paralytic shellfish poisoning have declined significantly, thanks to increased consumer awareness on the dangers of eating shellfish gathered in waters poisoned by red tide, as well as constant monitoring by BFAR in cooperation with local governments. BFAR regularly monitors and tests water samples from different coastal and marine areas nationwide to detect the presence of red tide toxins. Since 2000, there were reported cases of paralytic shellfish poisoning only in 2002, 2003, and 2005.

That said, harmful algal bloom still occurred in various parts of the Philippines, this time resulting to massive fish kills. The worse case of fish kill took place in Pangasinan in 2002, as the rapid expansion of mariculture activities — otherwise known as fishponds — hurt water quality. The high amount of ammonia, nitrite, and phosphate (mostly due to unconsumed fish feeds) caused a bloom that killed the fish. Miguel Fortes, professor at the University of the Philippines Marine Science Institute (UP-MSI), says fishpond owners greedy for a bigger harvest tend to overfeed their fish. But the uneaten feed ends up in the water, and so the fishpond owner has even less fish — live ones, that is.

Red tide can cause fish kills through several ways. One is through oxygen depletion.  Algae give off more oxygen during the day (through photosynthesis).  Lack of nutrients or unfavorable conditions of light, salinity, or temperature usually produced in stagnant waters can cause red-tide organisms to die, resulting in a mass of decaying cells. Bacteria in the water grow rapidly on these decaying cells, resulting in removal of all the oxygen from the affected waters, thus suffocating other marine animals. Or, the blooms become dense enough that they block sunlight and therefore destroy eelgrass beds, an important habitat for shellfish and other marine organisms. The blooms release toxins as well, thereby poisoning the waters and snuffing the life out of other organisms.