If your taste is global, frozen salmon better

SEATTLE – Forget the debate over farmed vs. wild salmon. Never mind the issue of food miles.

The most important thing to know about that salmon on your plate is whether it’s fresh or was frozen out at sea – the latter being better for the global environment, according to a new study conducted by researchers from Sweden, Canada and an environmental think tank in Portland.

“Popular thinking about how to improve food systems for the better often misses the point,” the researchers said in a news release.

The three-year study looked at salmon in the global sense, calculating its carbon footprint. That’s a different approach from other research telling us what fish to eat. You might see stickers on grocery-store fish saying it’s sustainably caught, for example, but that’s more a matter of whether a fishery is well-managed and whether other species are accidentally caught at the same time.

“These are all very important issues but they tend to be focused just on what’s going on in the water,” said Astrid Scholz, one of the new study’s co-authors. “They’re missing some of the main drivers for environmental change globally.”

A big one is transportation, she said.

“Fresh fish come on an airplane. That’s the only way it can get to you,” she said. And that flight has a high cost, in terms of greenhouse gases. If the fish was frozen, it could instead be transported around the globe on container ship, which uses far less energy, the research showed. In environmental terms, fresh fish is roughly twice as bad as frozen, according to the research.

“Fish shouldn’t fly. They should swim,” said Scholz, with the Portland nonprofit Ecotrust, an environmental think tank and advocacy organization. She conducted the research with academics in Sweden and Canada.

It counters the notion, embraced by many food activists, that buying “local” food is best for the environment.

She realizes that fish lovers may scream upon hearing her recommendations.

“We have this fetish with fresh,” she said. But she believes that a just-caught fish that is flash-frozen at sea tastes just as good as fresh.

Sven White, meat and seafood merchandiser at PCC Natural Markets, agrees that generally, “shoppers prefer fresh over frozen in season.” However, he said customers understand the environmental cost of flying fish in and do buy frozen, as well.

PCC does not sell farmed salmon. Scholz’s group, however, said that while farmed salmon may have an impact locally – the water around salmon farms may be more polluted, for example – that’s less important when you’re considering the planet as a whole.

The new study nonetheless advocated wild salmon over farmed, especially in the Northwest. Consumers in other places, where there are no wild-salmon stocks, rely on farmed fish. In that case, the researchers found the methods used on Norwegian farms were better than those used elsewhere.

For the study, the researchers used a method called Life Cycle Assessment, which for the first time examined the global salmon trade from cradle-to-grave: how they’re caught in the wild, what they’re fed on farms, how they’re transported and how they’re consumed.