Picture a big fish, like salmon, or tuna. Everyday, these big guys gobble up lots and lots of little fish to survive—an ocean hierarchy that up until recently was pretty sustainable.
But as global demand for seafood has increased in recent decades, the world's oceans haven't be able to keep pace. The World Bank reports that nearly two-thirds of seafood sold commercially worldwide will have to be farm-raised by 2030. Sounds like a simple solution, until you take into account the fact it takes about three pounds of wild forage fish like sardines, anchovies, and mackerel in order to feed one pound of farmed fish. That's the definition of unsustainable.
But what if farmed fish could thrive on a new diet? One that doesn't require fish at all? Thats the idea behind a new fish feed that replaces all of those forage fish with protein sources like insects, algae, and flax.
Up to 90 percent of wild-caught forage fish are never even consumed by humans—they go into pet food, poultry feed, and fishmeal for those farmed fish. Great for cats and chickens, but it leaves wild fish and marine mammals out of luck.
With the help of Dr. Rick Barrows, a research physiologist and fish nutritionist at the USDA, a seafood distribution company called TwoXSea has developed a new food for large farmed fish that bypasses other fish altogether.
Instead, the feed is made up of protein sources like insects, algae, flax, pistachio meal, as well as organic corn. And although it's a departure from what fish are eating in the wild, Barrows has discovered that at least eight species of fish—white sea bass, walleye, rainbow trout, cobia, arctic char, yellowtail, Atlantic salmon, and coho salmon—actually thrive on this semi-vegetarian diet.
Turns out, the nutrition fish need—a balance of protein, carbohydrates, fatty acids, amino acids, vitamins, and minerals—doesn’t have to come from traditional fishmeal. As Barrows told Bloomberg, “I don’t really think we’re turning a carnivorous fish into a herbivore. What I think we’re doing is taking soybeans and corn and algae and turning that into 'meat.' We’re really not changing the animal, we’re just changing what they consume.”
So, just like a human can be perfectly healthy as a vegetarian, fish can adjust to different protein sources. And some restaurants in the Bay Area of California that are serving up TwoXSea’s trout claim that the farmed fish is cleaner, high-quality, and has a flavor comparable to wild fish. The meticulous composition of the new feed may actually give farmed fish more optimal nutrition, which in turn is passed on to us.
Is this the future of aquaculture? Maybe, but for now, the cost of TwoXSea's fish remains high (an average of $1.50 more per pound than fish from the supermarket). Only time will tell if other fisheries will buy into this concept and thus create a demand that will make this solution more affordable. In the meantime, conscious consumers should shop smartly. Our sustainable seafood cheat sheet can help you make choices that won't hurt the world's fish supply—or your health.
Photo credit: John Loo via Flickr