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Photo by Alexander Raths

Trying to eat healthy and sustainably can be fishy business when it comes to seafood.

Here are the reasons why your seafood-buying choices matter.

By Haley Gray

Seafood. They say it’s good for us; they say it’s bad for us. Some stores and restaurants offer “sustainable” seafood, but what does that really mean? Is it healthier? Is it better for the planet? When it comes to eating sustainable seafood, deciding what to buy can be complicated.

The U.S. Department of Agriculture recommends people eat two servings of seafood per week. But the Environmental Working Group (EWG) says that directive is too broad to be useful—different fish have different nutritional value. And the fact that a certain species might be good for you doesn’t mean harvesting it was good for the environment.

We spoke to the EWG, the Natural Resources Defense Council (NRDC) and the Monterey Bay Aquarium to see what consumers should know when purchasing sustainable seafood.

Your first consideration should be health, says Sonya Lunder, senior analyst at EWG (and, incidentally, a Boulder resident). But consumers shouldn’t assume that any and all seafood has health benefits, she says. Rather, only some species have high fatty-acid content, i.e., lots of omega-3, which is the fat compound that makes fish such a stellar superfood and a nutritious protein source.

So consider how much fatty acid the fish you’re buying possesses. Species like salmon and swordfish, for example, have a great deal of omega-3, while catfish and tilapia do not. Omega-3 benefits the body in a number of ways, from reducing inflammation and easing inflammatory diseases to benefiting stroke and heart attack survivors and nourishing pregnant women and their babies.

Bycatch results when unwanted species are caught in nets and thrown overboard dead or dying. (illustration by Valentinash)

But a serious health threat is also associated with seafood: mercury, a dangerous neurotoxin linked to paralysis and impaired mental development in children. Due to atmospheric changes since the Industrial Revolution, higher mercury levels now exist in the oceans from global warming, soil erosion and runoff. Mercury collects in fish at exponentially higher levels the further up the food chain the species is—a phenomenon called biomagnification. This means some fish species are more prone than others to high levels of mercury contamination.

If a fish is high in omega-3, but also high in mercury, pregnant women and small children should avoid it. So consider both mercury and omega-3 content when choosing which seafood to eat, Lunder says. For example, while high in omega-3, swordfish also tends to be high in mercury, and is therefore best avoided. Salmon, however, is high in omega-3 and low in mercury, so it’s a good nutritional choice.

Lunder recommends consulting the EWG guide (compiled from heaps of USDA data) to make informed choices about what to buy. The guide cross-references omega-3 and mercury content, and even contains demarcations of species deemed environmentally sustainable by the Monterey Bay Aquarium. (See “Check Before You Buy or Dine” below for a list of seafood guides.)

Hook, Line & Sinker

Acidification, trash accumulation, pollution and overfishing all threaten the world’s oceans. Simply put, overfishing means humans are plucking fish from the water faster than the fish can replenish themselves. Molly Masterton, an attorney with the NRDC’s Oceans Program, says a third of fish stocks (a population of any given species) are threatened by overfishing, while 90 percent of fish stocks worldwide have fallen below historic levels.

How the seafood you eat was caught is an
important sustainability factor. Bottom trawling with large nets destroys delicate ocean habitats. (illustration courtesy mba seafood watch)

That’s why you should keep in mind fishing’s impact on the species you buy. Are so many fish being pulled from that population that it cannot replenish itself? Whether or not that’s the case, that information is not readily available to consumers. But the Monterey Bay Aquarium’s Seafood Watch program does monitor this issue and provides recommendations.

The next thing to consider is the impact that catching a certain fish has on other species. Bycatch is the unintentional gathering of marine species in commercial fishing nets that are ultimately discarded overboard dead or dying. Ryan Bigelow, Seafood Watch outreach program manager, says bycatch is a tremendous problem for oceanic health and a major contributor to overfishing.

Another concern is habitat damage. What impact on the natural habitat did the fish you buy have? Some collection processes, like bottom trawling, are extremely damaging to delicate ocean habitats. Trawling tears up ocean floors, which displaces, harms and kills other species and the environment they live in.

Perhaps the most perplexing issue is considering whether or not a management plan is in place for the species you purchase. Responsible fishing requires intention and restraint guided by experts and enforced, ideally, by government. In the United States, Bigelow says, management systems are actually quite robust, so American-caught seafood is generally a safe bet. But, he adds, if no management plan is in place, then the species may very well be at high risk.

Farming for the Future

Seafood is the most consumed protein source in much of the world. But with roughly 7 billion humans on the planet, there simply aren’t enough wild fish to feed everyone who eats it. If we want to keep enjoying seafood and its health benefits, Bigelow says we have to embrace fish farming.

“Even if all of the fisheries were managed at what we consider a ‘green’ [sustainable] level, there are not enough fish in the wild,” Bigelow says. “So we have to farm fish if we’re going to continue to eat fish.”

Land-based fish farms filter and recycle water in a system of closed tanks and have almost no potential to leak harmful waste, species or diseases. According to Seafood Watch, these systems are an exciting development in fish farming that hold promise for the future of sustainable seafood consumption. (photos courtesy Monterey Bay Aquarium Seafood Watch)

Bigelow says various criteria should be taken into account when choosing farmed fish, including the effect on nearby wild populations, the use of chemicals and the management of effluents. But the criteria get very complicated very quickly, even for experts.

Seafood Watch, which the Natural Resources Defense Council endorses, examines these factors and compiles ratings to guide consumers to sustainably raised farmed fish. The organization looks at what the fish are fed, if their waste contaminates nearby waters, if the farmed fish are escaping and invading the host ecosystem, if dangerous chemicals are used and/or leached into the natural environment, and other  things.

Most open-water farming methods, like submersible net pens and tuna ranching, are undesirable because of the high potential to leak both chemicals and the farmed species and their diseases into wild waters. Land-based closed-loop systems, however, filter and recycle water in a system of closed tanks and have almost no potential to leak harmful waste, species or diseases. Bigelow says these systems are an exciting development in fish farming that hold promise for the future of sustainable seafood consumption.

Better Buying Habits

With so many concerns, buying any seafood—farmed or wild—can be daunting. And with relatively lax labeling laws in the United States, Bigelow says it’s nearly impossible to adequately research and purchase sustainable seafood as an independent consumer.

That’s why the Monterey Bay Aquarium created the Seafood Watch seafood consumer guide and the Seafood Watch sushi consumer guide.

The guides list seafood and sushi by color rankings: green (the best, most sustainable options); yellow (decent options); and red (to be avoided). The EWG has a similar guide that depicts omega-3 and mercury content, and also indicates Seafood Watch recommendations. But why not recommend only green options? Bigelow says the task of moving markets toward sustainable-only seafood is so monumental that it’s wiser to encourage smaller changes, even if they’re not completely sustainable just yet.

He adds, “Even if farms aren’t perfect right now, it behooves us to improve them. They’re here to stay. There’s no getting around that.”


Check Before You Buy or Dine

courtesy Monterey Bay Aquarium Seafood Watch

Download Seafood Watch’s seafood and sushi consumer guides, which indicate which fish to buy or avoid by species, location and fishing method (farmed or wild caught), at www.seafoodwatch.org/seafood-recommendations/consumer-guides. You can also download the guides in app form from Google Play or the Apple Store.

A variety of EWG resources, including an age- and weight-based seafood recommendation tool and other guides, are available at www.ewg.org/research/ewgs-good-seafood-guide.

The Monterey Bay Aquarium “partners” with restaurants, suppliers, fisheries, packaged-food producers, retailers and organizations that commit to building awareness about ocean-friendly seafood choices. A list of partners for every state and country can be found at www.seafoodwatch.org/businesses-and-organizations/partners.