What all this means is a creature that, while very modest in appearance, is in fact remarkably potent and efficient in both cleaning the ocean and providing humans with protein, fat and essential nutrients. One need only compare it to the much more frequently consumed forms of seafood for its positive qualities to shine even brighter.
Consider salmon, the most consumed finfish in America, most of which come to us in farmed form. Farmed salmon might be silvery bright on the outside and lustrous orange on the inside, but to bring all that appetizing beauty to market involves considerable environmental inputs. In the early days of salmon farming, it could take as much a six pounds of wild fish to grow a single pound of farmed salmon. To its credit, the salmon industry has greatly reduced that ratio over the last 30 years, but they have done so by putting a lot more soy and other land agricultural products into salmon feed. All this adds up to a product that costs the planet much more than a mussel. Because you don’t have to feed mussels anything at all—they feed themselves.
The Trouble with Tuna
At this point, the purists among us might throw up their hands and say, “Well forget it. From now on I’ll only eat wild seafood.” This “solution” is also remarkably shortsighted. Take for example the second most consumed seafood in America, the 23-odd species of fish grouped roughly under the market name “tuna,” most of which are wild-caught in the far corners of the world. Having overharvested our domestic tuna stocks, we now rely on tuna spirited away from the portions of the ocean that fall under no nation’s jurisdiction. Fish catches from poorly regulated “high seas” regions have increased by 800% over the course of the last decade because there is simply no more room for the tuna industry to grow any larger, and many tuna stocks are now overexploited.
And what is true of tuna is true of all wild fish. The global catch of wild seafood flat-lined at around 85 million metric tons twenty years ago and is unlikely to ever increase. Lest readers think we could farm our way out of a tuna shortage, think again. The thing that makes tuna so sexy—their speedy sleekness, their high-energy thick steaks— is the very thing that makes them poor choices for farming. Early experiments in farming tuna have shown that it can take as much as twenty pounds of wild fish to grow a single pound of farmed tuna.
Photo: Amy Kumler.