Fish Tales: How Sustainable is That Tuna in the Window?

Enviro sushi lovers in the U.S should be celebrating—a Japanese company is now selling farm-raised bluefin tuna offering all the “buttery texture” without savaging threatened wild tuna stocks. So why are so many environmentalists still so upset? Fifty years ago, fish farming wasn’t an issue for anybody. Today, fish farming accounts for about half of all the fish consumed in the world. That’s only going to grow, because global fish stocks, for Pacific tuna, Atlantic hake, or Patagonian toothfish, are in terrible shape. The UN estimates 70% of global fish stocks are at or beyond their limits already and urges even more fish farming as a way out of the mess. That drives a lot of environmental groups crazy. Greenpeace, for instance, rails against all sorts of nasty side effects from intensive fish farming, like nutrient run-off that fouls local water supplies. But the biggest problem, Greenpeace says, is bad math...WSJ

Bad math? Greenpeace says it takes more fish to feed the farmed fish than you get back in fish weight. I'd call this an "Ethanol of The Sea" situation.