The Environment Report

SHOCK AND AWE WERE MY REACTIONS WHEN, FOR THE first time in my life, I saw a whole tuna fish. It was being carried on the hunched shoulders of a fisherman in General Santos City. My fascination gave way to a mixture of pity and revulsion, realizing the fisherman could have been carrying a corpse.

I grew up in the city, and the only tuna and sardines I ever saw came in cans from the supermarket. If entire sardines could fit into a can, then, I figured, it was the same way with tuna.

All that ignorance was a reflection, too, of the deficiencies of our educational system. Even today with all the talk about environmental protection, many Filipinos grow up not learning about the rich diversity of marine life that we have, one that includes, besides sardines and tuna, whales and dolphins and the butanding.

Albacore tuna, I always thought, was “American” tuna because that was the label on stateside canned tuna. It turns out that the Philippines exports albacore, which is only one of several species of tuna. Besides albacore, we also export skipjack, bigeye, and yellowfin. The last is considered as one of the best types of tuna. Just go to a Japanese restaurant and you’ll find Japanese tourists ordering yellowfin sashimi, our local prices dirt cheap compared with what they’d have to pay back home.

48 species

I don’t know if it was yellowfin sashimi that made it to the latest issue of Time magazine but it was definitely tuna with its distinct red color (most fish are white). Time had several stories around “tuna trouble,” the dwindling supplies brought about by overfishing. GenSan kept coming up in the articles. A a slide show on the Time website graphically shows how Manny Pacquiao’s hometown was built around tuna and how it is threatened today.

Reading through the articles got me thinking of how the tuna should be used as a case study for different courses. Biology would seem to be the most obvious, but the tuna could be mentioned as well in chemistry, physics and of course ecology or environmental science. Medical and nursing schools will be surprised to find tuna fitting into their physiology classes. Besides the natural and medical sciences, tuna can be used in discussions of economics, history, anthropology, political science, geography—and even ethics. I’ll try to explain, in one column, how tuna can fit into all these sciences.

Let’s start with the natural sciences. “Tuna” is used to refer to 48 species of fish, all of them belonging to a family called Scombridae. The different species of tuna are distinctive with their rose-colored flesh, the color due to high levels of myoglobin. Humans and other mammals have hemoglobin in our red blood cells, which is responsible for transporting oxygen. Myoglobin is found in the muscles, and you can see why the tuna evolved to carry this important oxygen-binding substance: tuna are rapid swimmers and can survive in very cold waters.

Tuna are important in many ecosystems. They are carnivorous, preying on many smaller fish species. In ecological jargon, these fish are high on the food chain, meaning if their populations decrease, it means many of their prey will multiply more rapidly, with often unknown effects on the ecosystem.

Tuna also have some interesting relationships with other marine life. For example, they tend to “travel” together with dolphins. This association seems to protect them from sharks. Unfortunately, tuna trawlers used this to their advantage. By following pods (in Tagalog, barkada) of dolphins, they could then go for the tuna. The trouble was that the dolphins then got entangled in the nets, resulting in many casualties.

Environmental groups pressured the tuna industry to come up with “dolphin-safe” fishing methods so you’ll sometimes find canned tuna with that assurance, but there has been an unintended side effect here: dolphin-safe tuna fishing resulted in other “corollary damage,” this time sharks and turtles. You can see the dilemmas here not just for environmentalists but also for ethicists (can one animal species’ life be more important than another’s?).

Insatiable

Historical records show that even in ancient times, Roman soldiers were known to take dried tuna with them on their military expeditions. Today, the main demand for tuna comes from the Japanese. Ironically, the Japanese themselves have no tuna to catch in their own waters, and have to source their supplies from other countries. Atlantic bluefin is the most prized but comes all the way across the world.

The Japanese know their supplies are endangered and the government has agreed to an annual import quota of 6,000 tons, but in reality, might actually be importing double that amount. Not only that, the Japanese taste for tuna sashimi has spread throughout the world, so the global demand has taken off and now almost seems insatiable.

GenSan’s fishermen (I know, the politically correct term is fisherfolk but I find it awkward) still use traditional methods for catching tuna, with small boats and handline (manual) techniques but they’re finding that they have to go further out to the sea to get tuna. Smaller fishing boats are losing to larger fishing companies that can go as far out as Indonesia and Papua New Guinea.

We might want to learn from the experiences of the Mediterranean countries, where the once flourishing tuna industry is fast disappearing. There’s no room there for smaller fishermen and large fishing companies have taken over, using large trawlers complete with sophisticated GPS (global positioning system) to track down the tuna. Some have gone into “tuna ranching,” casting out nets to trap schools of tuna and allowing them to fatten up on small fish before harvesting. Again, small fishermen are at a disadvantage.

As Mediterranean supplies dwindle, these large fishing companies have gone into African waters. It was an Ethiopian friend who told me, fuming, about this emerging problem. I did some research and indeed, the estimate is that African countries lose some $1 billion a year from the trawlers’ “piracy” of tuna, shrimp, mackerel and other marine life. Not only that, the huge trawlers end up polluting the waters and destroying marine habitats.

Will Mindanao (Davao is another tuna area) follow the fate of the Mediterranean tuna industry? It depends on our choices. Australia and some European countries are already starting with tuna aquaculture, but questions have been raised too about that option because it means having to get large supplies of small fish to feed the tuna.

In many ways, GenSan residents are very much like the tuna, caught in nets with many competing interests: small fishermen versus large tuna companies, local tuna demand versus overseas demand, even tuna connoisseurs versus vegetarians, the latter arguing that the solution is putting a complete end to the demand for tuna, and all forms of meat, mammal, bird or fish.

Email to mtan@inquirer.com.ph