For the last 20 years, Americans have been having a conversation about sustainable seafood that was largely focused on fish purchased at restaurants or fresh seafood counters. Armed with seafood guides, thoughtful customers were encouraged to pose questions about where their fish was caught and what type of gear was used — questions that are far trickier to pose in front of a wall of canned tuna in the middle of a supermarket.

While tuna poke may be winning over American palates today, our consumption of fresh tuna is still dwarfed by our collective appetite for the canned stuff. According to the National Fisheries Institute, Americans ate more than 700 million pounds of canned tuna in 2015. That's 2.2 pounds per person, enough to keep it firmly among the top three seafood items Americans consume, a ranking held for more than a decade.

Unlike the sustainability conversations we tend to have over farmed vs. wild salmon — or on issues like bycatch, mangrove destruction or human slavery that swirl around shrimp — the hand-wringing over canned tuna has largely been focused on contaminants like mercury, rather than fishing methods or the health of fish stocks.

A handful of retailers are about to change that.

Last Wednesday Whole Foods Market announced that by January 2018, all canned tuna sold in its stores or used in its prepared foods departments will be sourced from fisheries that use only pole-and-line, troll or handline catch methods that eliminate bycatch (accidental harvest of other fish, birds or mammals) because fishermen are catching tuna one at a time.

The new Whole Foods' policy also requires canned tuna products to come from fisheries that are certified by the Marine Stewardship Council (MSC) or are sourced from fisheries rated green (best choice) or yellow (good alternative) by the Monterey Bay Aquarium and The Safina Center. And Whole Foods has included a traceability requirement as well.

"There are a lot of points in the supply chain where tuna changes hands. We want to map it from catch to can. That's critical," says Carrie Brownstein, global seafood quality standards coordinator for Whole Foods Market.

The new requirements coincide with many of the new compliance rules designed to improve traceability of imported seafood in NOAA's Seafood Import Monitoring Program, which also goes into effect in January 2018. Like the vast majority of seafood in the U.S., much of the canned tuna we eat is imported from overseas, with Thailand, Ecuador, Vietnam, Philippines and Indonesia topping the list.

Brands like American Tuna, Wild Planet, Pole and Line, Henry and Lisa's and the in-house 365 Everyday Value brand are already sold by Whole Foods, and should fare well under the store's new rules, but they aren't found in every supermarket.

Also rethinking the tuna aisle is Hy-Vee, a 240-store grocery chain found in the Midwest. Once the chain met its sustainable seafood goals for its fresh and frozen seafood departments, Brett Bremser, executive vice president of perishables, says the company was ready to get its private canned tuna label up to spec as well.

In late January, Hy-Vee announced its new canned tuna policy, citing concerns over high levels of bycatch in fisheries that use fish-aggregating devices, also known as FADs, used by some of the larger canned tuna companies like Bumble Bee Foods to catch skipjack tuna.

"There's a huge issue of bycatch with those," says Ryan Bigelow, program engagement manager with Seafood Watch. "FADs can be anything from a bamboo raft in the ocean to a large platform. You wait for the little fish to congregate under it, and then other fish come, and soon, you have all sorts of animals swarming around the platform. A purse seine is used to surround it, and it all goes into the net" — including animals like dolphins, sea birds, rays, juvenile tuna and other non-targeted fish.

Like Whole Foods, Hy-Vee will be sourcing canned tuna that is certified by the MSC, or is harvested from fisheries that are rated green or yellow by the Monterey Bay Aquarium's Seafood Watch program. However, Hy-Vee is not yet incorporating these standards into its prepared foods department.

Pittsburgh-based Giant Eagle announced its own "ethical canned tuna policy" — pledging to source tuna from well-managed stocks for its store brand — last year. And back in 2012, Safeway led the way, committing to source its private label skipjack canned tuna from FAD-free fisheries.

Kathleen Mullen-Ley, a project director with FishWise, a nonprofit sustainable seafood consultancy that helped Hy-Vee develop its canned tuna policy, says she expects more retailers to follow suit.

"In the past, the canned fish aisle was not associated with a retailer's brand in nearly the same way as fresh and frozen seafood," she says in an email to NPR. "It's not intuitive for people to associate a small gray can of tuna back with the ocean."

Most canned tuna products sold by retailers don't have their name on it. Brands like Chicken of the Sea, Starkist and Bumble Bee dominate the market, so there was less incentive for retailers to focus their attention here, she says.

But Hy-Vee's Bremser says the segment is ripe for change.

"The manufacturers have to understand it's important to us and to our customers. As more stores like Hy-Vee, Whole Foods and Giant Eagle take strong positions on canned tuna, the major label suppliers will have to step up as well," says Bremser.

The industry does seem to be moving in that direction. In 2015, Bumble Bee launched its Trace My Catch program, where consumers can type in a code found on their can of tuna to get more information on the species and gear used. But David Pinsky, senior oceans campaigner for Greenpeace, which developed its own tuna shopping guide, says it doesn't go far enough.

"It gives the consumer the impression that Bumble Bee is sourcing sustainable seafood, but it lacks information on the impacts on species. FADS and long lines have significant impacts on juvenile tuna, sharks, rays and seabirds. That's not mentioned in the traceability," he says. "And there's no mention of human rights concerns."

Bigelow of Seafood Watch says what's important to understand is that just because canned tuna looks the same, doesn't mean it is. And he says there are a few key phrases consumers should look for on can labels.

"Dolphin-safe isn't enough anymore," he says. "Look for pole and line caught, labels that say FAD free, and some kind of certification is usually a helpful guide. Those are the big ones."

SeparatorCopyright 2017 NPR. To see more, visit