The world's tuna trade is becoming unsustainable. Of the world's 19 non-bluefin commercial tuna stocks, half are now overfished or at risk of going extinct. Even General Santos, known as the "Tuna Capital of the Philippines," finds its sashimi export and canneries taking a hard hit. Fishermen used to make single-day trips to catch giant yellowfin, which like the bluefin, are sold for sashimi. Now, even the smallest of those tuna are at least a 3-day trip out to sea.