Aquaculture farm system. (Photo: Pan Xunbin/Shutterstock)

Four in five Americans say it is important or very important that their seafood is sustainably caught, and more than 60 percent of international consumers agree with them. Isn’t that wonderful?

Not entirely. There’s a limit to how much seafood we can sustainably catch—that’s the whole point of sustainable seafood—and demand already outstrips supply. To bridge that gap, fisheries and retailers are fudging their promises about fishing methods, catch sizes, and location. In return, sustainability accreditors are allegedly letting their own standards slip, which compounds the problem.

Yes, seafood lovers: You should start worrying about the possibility of blue-washing.

Walmart provides a good example of how the process has unfolded. In February 2006, the company announced that within five years it would sell only seafood certified by the Marine Stewardship Council, the best-known accreditor of sustainable seafood. Walmart is the world's largest retailer of seafood—and just about everything else—so suppliers scrambled for sustainability credentials. Demand for MSC certification rose sevenfold.

"If retailers are representing the seafood they’re selling as sustainable and reaping benefits from it, they have an obligation to ensure that the status of the fishery is truly healthy and is not causing irreparable ecological damage."

Critics say, however, that MSC has certified unsustainable fisheries in an attempt to satisfy demand and its own budgetary requirements. Two years ago, NPR ran a series about the non-profit, in which several experts said MSC could not guarantee that MSC-certified seafood was sustainable. One called relying on the MSC label a “gamble.” The group’s structure is also in question: The organization was established in partnership with industry, and the council gets much of its funding from licensees. This arrangement raises the appearance of a conflict of interest, but there are some safeguards in place. For instance, licensees pay to be assessed by an independent party, whether or not they receive certification. MSC defenders also point out that the group’s funding money has to come from somewhere.

The more important allegations concern the quality of MSC’s standards. For example, many boats that supply MSC-certified swordfish use longlines, whose thousands of hooks are known to ensnare tens of thousands of sharks annually. Some boats catch five times as many blue sharks as swordfish, and many of the sharks die within days of being tossed back into the ocean.

“It’s not really a swordfish fishery that happens to catch sharks,” Steven Campana, an ocean scientist for the Canadian government, said of one fishery. “It’s a shark fishery that happens to catch swordfish.”

That’s inconsistent with MSC’s certification standards, which require accredited fisheries to protect the “function and diversity of the ecosystem.” Many analysts say that the level of shark by-catch is not sustainable, although MSC rejects that claim.

Nine years has passed since Walmart made its promise, and the retailer is still selling fish without sustainability cred. Even as MSC certifications have accelerated, the superstore chain hasn’t been able to source all of its seafood from certified fisheries.

Instead, many Walmart suppliers participate in Fisheries Improvement Projects, which sounds like it means they’re sustainable. It doesn’t. FIPs are supposed to move step by step from overfishing to eventual MSC certification. In order to gain access to retailers like Walmart, however, a fishery must only develop a plan to improve ocean management. It doesn’t have to take actual steps to carry out its plan.

An article in the journal Science shows how problematic this system is. Two out of three FIP-participating fisheries in developing countries—which supply about half of the international seafood market—have not yet made measurable moves toward sustainability. Some have been treading water in the planning stage for six years—during which they’ve had access to major retailers like Walmart. Those fisheries that have finally taken concrete steps have been in the system for more than five years, on average.

When it comes to the seafood counter, you should muffle your anti-Walmart tirades. I’ve chosen it as an example because the company is big and its difficulties so public. Many other retailers have run into exactly the same issues. These companies haven’t handled the problem perfectly, but they’re in a difficult position: The public is demanding unsustainable levels of sustainable seafood.

(Photo: Marine Stewardship Council)

“There are not enough truly sustainable fisheries on earth to sustain the demand,” says Jim Barnes, director of the Antarctic and Southern Ocean Coalition.

Sustainability certification, even if imperfect, is still better than what we had a generation ago: virtually unlimited fishing, paired with complete consumer disregard for environmental issues.

“We don’t want retailers backing away from these commitments—these are positive steps,” says Jim Sanchirico, an author of the Science study. “But we need better oversight to ensure that fisheries are working through the process.”

Progress is ongoing. The Marine Stewardship Council is working with other conservation organizations to improve the science that undergirds their certifications. The Conservation Alliance for Seafood Solutions recently issued guidelines to improve the administration of FIPs. Fish sellers must also do their part to amend the system and resist the temptation to mislead consumers about seafood sustainability.

“If retailers are representing the seafood they’re selling as sustainable and reaping benefits from it, they have an obligation to ensure that the status of the fishery is truly healthy and is not causing irreparable ecological damage,” says David Newman, a fisheries policy expert in NRDC’s oceans program.

If you’re worried about provenance of your sustainable seafood, visit FishSource.com, which tracks the progress of Fishery Improvement Projects, or contact the Marine Stewardship Council with your concerns. Most of all, avoid retailers that aren’t even trying to achieve sustainability and keep caring where your shrimp cocktails, tuna tartare, and swordfish steaks are coming from.

This post originally appeared on Earthwire as “Demand for Sustainable Seafood—Gone Overboard?” and is republished here under a Creative Commons license.