If you love seafood, you’ve probably heard that wild fish are in trouble. To protect free-swimming fish, it makes sense to eat farmed ones instead — and what tastier way to lend a hand than by eating farmed salmon, right? In reality, however, chowing down on farmed salmon does nothing to protect their wild cousins.

Salmon farming has expanded rapidly in the last thirty years. These fish have become America’s favorite seafood after shrimp, and around 70 percent of the salmon we eat comes from farms.

It seems logical that we’d be catching fewer wild fish with all those farmed fillets flooding the market. But that’s not the case, said Michael Kohan, the Seafood Technical Director for the Alaska Seafood Marketing Institute. Wild salmon fisheries are managed with one specific goal in mind: Maintaining fish populations at a sustainable level.

“How we manage our salmon is independent of any farmed salmon operations or consumer preference for farmed salmon,” Kohan said. “It’s all based on sound science to reflect the most sustainable harvest levels, so that we have returning stocks for future generations.”

Supply drives demand

If farming slashed demand for wild salmon, wild catches should have declined while farmed production increased. Instead, the harvest of wild salmon globally has stayed fairly steady since the 1980s, even as the production of farmed salmon skyrocketed.

Our appetites have kept pace with the glut of farmed fish. In the United States, salmon consumption more than doubled since the rise of farmed salmon, from less than 130,000 metric tons in 1989 to over 300,000 metric tons in 2004. It seems that the more salmon is available, the more people will eat.

Fishermen can’t catch more wild fish to meet demand — that would lead to overfishing, and low harvests in the future. Andy Wink, a seafood economist with the McDowell Group, said that in many industries, a company can “make as many widgets as the market demands of them.” In comparison, “wild fisheries are totally different.”

The bottom line is that aquaculture has no effect on how much wild salmon is caught each year. So, if salmon farming doesn’t help wild fish, does that at least mean it doesn’t hurt them? As it turns out, farmed salmon has spawned a host of problems that exacerbate overfishing, pollution and disease — all of which hurt ocean wildlife.

Hidden harms

Salmon are carnivores, so they need to be fed fishmeal and fish oil to grow. That fishmeal and fish oil comes from wild-caught anchovies, sardines and other small species. So, farming salmon results in more fish being taken out of the ocean, not less.

Salmon farms take a toll on ocean habitats, too. “What people don’t see is that farmed salmon are grown in pristine places, like the fjords of Chile, where it’s polluting the environment and actually depleting a lot of wild fisheries,” said Liesbeth van der Meer, Oceana’s leader in Chile.

Van der Meer explained that because the fish are crammed in pens at high densities, they easily transmit parasites and diseases, including the deadly bacterial illness piscirickettsiosis. Wild fish can pick up these infections as they swim past farms. To combat disease, farmers douse their salmon with tons of antibiotics and pesticides. These chemicals — along with feces and uneaten food — build up a layer of toxic gunk on the seabed beneath the farm.

Chile has never been home to wild salmon, but its coastlines and rivers are now populated by invasive salmon that escaped from farms. These fugitive fish prey on native species, changing the dynamics of the ecosystem.

If environmental laws don’t prevent it, van der Meer said, salmon farm production in Chile could be ramped up indefinitely. This helps explain why Alaska has banned salmon farming to protect its wild salmon fisheries.

Many seafood watchdogs and sustainability advocates consider wild Alaskan salmon to be one of the world’s best-managed fisheries. Americans used to eat a lot of our domestic wild salmon. Now, however, 80 percent is shipped overseas to be processed, and just a fraction finds its way back home.

Wink said that it’s tough for wild fisheries to compete against farms because wild fisheries will always be limited by environmental factors, such as productivity and season, whereas farms don’t have these constraints. In the case of a well-managed salmon runs like those in Alaska, Wink explained that “the best way to support wild fisheries is to eat wild fish.”

Originally published by OCEANA