I saw this story yesterday on the BBC, which reports on the danger of collapse of bluefin tuna stocks, and didn’t cover it then because I thought it was the sort of thing that would get plenty of media attention. The fact that the not-terribly-environmentally-minded US is supporting a 3-5 year ban on tuna fishing in the North Atlantic says the situation is serious.

I am stunned to see today that when I put “tuna” into Google News, I got all of 5 articles on this issue (BBC, a New York Times editorial, Fish Update, the Telegraph, and the Edmunton Sun).

Readers may note that I have never advocated any particular pro-environment course of action, so I hope you will take this request seriously.

As much as I am a sushi-holic (and tuna is a prized offering), I have been avoiding tuna for some time, not so much for the stock collapse issue (I was unaware of that until recently) but because it is very high up the food chain. You consume a lot of ocean food energy when you eat tuna. And believe me, I am not as virtuous on the environmental front as I’d like to be, but for the vast majority of people, food is one area where it is relatively easy to implement changes (and I anticipate it will become more a focus of attention in the next few years).

A crude rule of thumb is that every time you go one step up the food chain, you get only 10% of the calories you’d get by consuming the next lower item (note I am not sure how this is measured, whether by weight or portion size. Carbohydrates and proteins have the same amount of calories per unit weight, but fats have more than two times as many calories per gram as carbs and protein). So say you eat corn-fed beef. It took ten times the amount of corn to produce that unit weight of beef (and that may not even allow for waste, like skeleton and hide).

Tuna is a top predator. I recall reading it can be as high as 10 levels up the food chain, and per the chart below, it is routinely 4-5 levels up. So tuna is one of the most environmentally costly foods. (Anyone who has better factoids on this matter is encouraged to contribute, but directionally, this depiction is accurate, even if the particulars are a bit off).



So please, no more tuna! And (nicely) encourage any restaurant you frequent to stop serving it.

From the New York Times, “The Bluefin Slaughter“:

The hunting of highly valued animals into oblivion is a symptom of human foolishness that many consign to the unenlightened past, like the 19th century, when bird species were wiped out for feathered hats and bison were decimated for sport. But the slaughter of the giant bluefin tuna is happening now. An international conference that ends tomorrow in Turkey could help to rescue the bluefin, a noble, ocean-crossing predator, from the brink of collapse — or seal its doom through empty promises and inaction. The United States has gone to the meeting urging a ban on bluefin fishing in the eastern Atlantic and Mediterranean. The world should heed it. Think of a giant bluefin as an 800-pound torpedo of sushi — some of the finest, fattiest, most expensive there is. Since the 1970s, when the sushi craze took off, purse-seine haulers and longline fishing boats and fish hunters in spotter planes have chased the giant bluefin across the world’s oceans. They have been ruthlessly efficient: The worldwide bluefin population has plunged more than 90 percent in the last 30 years. There are bluefin tuna “farms” — large-scale ranching operations in the Mediterranean, but these are no less destructive than boats on the open seas. Farms catch their fish in the wild, young and small, exploiting a loophole in rules that set limits by weight. The tuna are fattened in pens, like foie-gras geese, using vast supplies of smaller fish whose plundering is its own ecological disaster. Scientists of the International Commission for the Conservation of Atlantic Tunas recommended last year that the annual catch in the eastern Atlantic and Mediterranean be lowered to 15,000 metric tons to let the fish recover. The commission instead set a quota that was practically twice that: 29,500 tons. The evidence so far suggests that the actual catch this year will be 40,000 to 50,000 tons, said William Hogarth, director of the National Marine Fisheries Service, who is at the commission’s meeting in Turkey to plead for the moratorium. Blame for the crisis is global. The European Commission has promoted ruinously excessive fishing quotas. The United States is a major source of sushi demand, and must do much more to protect the bluefin in one of its important spawning grounds, the Gulf of Mexico. And a huge slab of raw guilt should be placed on Japan, the world’s most voracious fish consumer, whose appetite for the bluefin has done the most to make it disappear.

And from the BBC: