Frozen salmon have smaller carbon footprint than fresh

Eat your frozen salmon. Preferably wild, frozen salmon.

A new study out of Portland shows that frozen salmon consume less energy from net to table than do fresh. And farmed salmon “have a heavy hidden demand on fossil fuels,” the study’s authors said, because the feed can be either forage fish, which would be more efficiently fed directly to people, or corn and soy, which require fuel for growing and harvest.

Ecotrust The Oregonian's Abby Haight.

Ecotrust examined the carbon footprint of catching, harvesting and transporting wild salmon around the world. They found that flash-freezing at sea and shipping later used less energy. Container ships are the most environmentally friendly transportation, the study showed. Most salmon sold around the world, however, are fresh, and never frozen.

For instance, salmon that are flash-frozen at sea can be transported by freighter or train, which uses significantly less fossil fuel than jets. Troll-caught fish burn diesel fuel as ships chase fish across the seas. An Alaska salmon caught by a purse seiner, however, has a low carbon impact, Scholz said.

The study could have broad implications on consumer choices for seafood, Haight writes. For example, the influential group Seafood Watch from the Monterey Bay Aquarium is likely to include production and distribution of seafood in its consumer guides.

-- Rita Hibbard