Bluefin tuna belly
Source: Wild, Farmed
Mercury Risk: Extreme
Toro (or hon maguro, as it’s sometimes called). Bluefin tuna — there’s nothing quite like it. The soft delicate taste, the silky ethereal texture, the lingering hedonistic delight that resonates long after the delicate morsel has slipped softly down your throat.
It’s an incredible dish. I love it, you love it, everyone loves it—but we are loving it to death.
Toro is the general term for the belly flesh of a bluefin tuna and can be divided into two main types: chu-toro, cut from the less fatty sides of the belly, and o-toro, the belly’s supple and glorious center. The allure of o-toro is matched only by its price: It can easily be the most expensive item on a sushi menu.
While toro can be cut from any large tuna, the quintessential toro experience is associated with the majestic bluefin tuna, known as hon maguro or kuro maguro, the largest and most highly prized member of the tuna family. It is also the most expensive fish in the ocean: A single animal once fetched 174,000 dollars at Tokyo’s Tsukiji fish market.
Price tags of such magnitude launch a lot of ships. The various bluefin species are caught in both the Pacific and the Atlantic, and tuna fleets from dozens of countries pursue their quarry wherever it is found. The bluefin has been ruthlessly exploited to the point that stocks are on the verge of collapse.
Bluefin tuna populations in the western Pacific are estimated at less than ten percent of their virgin levels. Populations in the Atlantic are also in dire straits. To worsen matters, bluefin is generally longlined (caught on long ropes with thousands of baited hooks in series). As discussed in other chapters, this indiscriminately impacts many other animals. Hundreds of thousands of dead fish, seabirds, and turtles are discarded by bluefin tuna hunters every year.
The high market value of bluefin has given rise to an ominous new industry: the bluefin tuna ranch. These farms are unsustainable by their very nature. Farming bluefin is akin to farming tigers—top-of-the-food-chain carnivores who demand large amounts of protein. For every pound of tuna that comes out of a bluefin farm, twenty or more pounds of fish have gone in. Practicing aquaculture this high on the food chain is environmentally dangerous. Worse, these ranches typically capture wild juveniles and rear them rather than raising the fish from eggs. Until a better way of raising this fish is developed, it’s best not to support this industry.
Bluefin is also a poor choice for those concerned about mercury. Very high levels of the metal have been found in both Atlantic and Pacific bluefin.
The bottom line is that bluefin is more than a delicacy — it is an essential but extremely vulnerable part of our ocean ecosystem. This is a fish that should be should be venerated and protected, not wiped from the face of the deep in a relentless crusade of greed and gluttony.
Casson Trenor is a frequent commentator on sustainable seafood issues. He has been featured in regional, national, and international media outlets, including CNN, NPR, Forbes, New York Times, Boston Globe, Christian Science Monitor, San Francisco Chronicle, Los Angeles Times, Seattle Times.