What Is Sustainable Seafood?

Jun 13, 2023

Farmed vs. wild-caught? Pole-and-line vs. troll-caught? What does it all mean—and why is it important, anyway?

People are encouraged to eat more fish to gain its health benefits, but as you up your intake, you may want to take sustainability issues into account.

As the world's population increases, along with per capita seafood consumption, we’re harvesting fish in ways that can pollute ocean waters and damage habitats. And we are using technologies—like huge seafood harvesting and processing factory ships that can stay at sea for months at a time—that allow us to catch fish faster than they can reproduce, according to Seafood Watch, at the Monterey Bay Aquarium in California.

A number of long-term solutions are being developed, including different ways of catching fish in the wild and, increasingly, farmed fish—raising seafood in pens, ponds, or tanks. But coming up with effective, affordable solutions isn't easy.

Here are the terms related to sustainability that you’re likely to see while shopping for seafood, and what you need to know about each, as well as our advice on what to look for when searching for sustainable fish and shellfish.

In recent decades, fish in the wild have been caught using a variety of huge nets or dredges that exponentially increase the number of fish caught and, over time, deplete populations of key species. In many cases, these techniques also have the unintended harm of catching other species—including turtles and marine mammals—and damaging marine habitats.

Farmed fish has the potential to reduce those risks, according to Seafood Watch. Seafood now commonly raised this way includes shellfish, salmon, shrimp, striped bass, tilapia, and trout.

Taste differences between farmed and wild fish of the same type tend be slight, says Davis Herron, vice president of Lobster Place Seafood Hall at Chelsea Market in New York City. Farmed salmon tends to be fattier than wild-caught, for example, but that doesn't mean that farmed tastes better or worse than wild, he says.

Several things can influence the nutrition and safety differences between farmed and wild fish. For example, because of the controlled environments in which they are raised, farmed fish may be less likely than wild fish to be exposed to harmful pollutants, such as mercury, and more likely to have consistent levels of omega-3s and other nutrients, says Jason Bolton, PhD, a seafood safety specialist and associate dean at the University of Maine Cooperative Extension in Orono. On the other hand, farmed fish may be raised in crowded conditions, making them susceptible to disease and parasites, like sea lice. They could then be treated with pesticides or antibiotics, which can remain in the seafood or get into surrounding waters.

Some species of fish, particularly larger ones like tuna, swordfish, and cod, can't be raised easily in farms. In recent decades, they were often caught in the wild with nets or fishing lines that could be many miles long and have thousands of hooks, called longlines. Both of those techniques posed substantial risks of overfishing and catching unintended, potentially threatened species.

As an alternative, some fishing companies are turning to pole-and-line fishing, as well as jigs and trolling lines. With those methods, unwanted species can be more easily released.

The downside: They are more labor-intensive, so some fish caught this way may cost more. For example, in our tests of canned tuna for mercury, we paid between $2.75 and $3.49 for a can of Wild Planet Skipjack Wild Tuna, which the company says is "100% pole & line or troll caught." By comparison, Bumble Bee Chunk Light Tuna in Water, which doesn't indicate on the label what fishing method is used, costs between 89 cents and $1.99.

Organic foods have a reputation for being more sustainable, but when it comes to fish and shellfish, the term is meaningless. Some places sell fish labeled "organic," but "there's no such thing," says University of Maine seafood safety specialist Jason Bolton. The Department of Agriculture, which sets standards for organic meat, poultry, and other foods, hasn't developed rules for farm-raised seafood. And wild-caught seafood can't be considered organic because its environment isn't controlled.

Although experts can't say whether farmed or wild-caught is better overall, they do offer some general advice to guide your shopping.

If cost is your primary concern, you are usually better off choosing farmed fish over wild. For example, wild salmon can cost twice as much as farmed, or more.

When choosing farmed, look for fish raised in the U.S., which tends to have more oversight in the use of pesticides or antibiotics than fish raised abroad.

Finally, consider species such as tilapia or catfish, which are omnivores and can be fed on insects or algae instead of other fish. That's important because some farmed fish are fed meal or oil made from other fish, which can contribute to overfishing.

For more information about the sustainability of particular species of fish, check out Seafood Watch's guide to sustainable seafood.

Tired of salmon or shrimp? Fishmongers from the famed Pike Place Market in Seattle and Chelsea Market in New York City offer a few alternatives. These fish are all relatively low in mercury and good sources of omega-3 fatty acids, with sustainable options readily available. And some may cost less than more familiar varieties.

Editor's Note: This article also appeared in the July 2023 issue of Consumer Reports magazine.

Lauren Kirchner

Lauren Kirchner is an investigative reporter on the special projects team at Consumer Reports. She has been with CR since 2022, covering product safety. She has previously reported on algorithmic bias, criminal justice, and housing for the Markup and ProPublica, and was a finalist for the Pulitzer Prize in Explanatory Reporting in 2017. Send her tips at [email protected] and follow her on Twitter @lkirchner.

Althea Chang-Cook

Althea Chang-Cook is the associate director of content at Consumer Reports, covering food and kitchen gear, as well as stories for diverse audiences. She also edits many of CR's Outside the Labs evaluations and a wide variety of other content. Prior to joining CR in 2018, Althea covered food, health, parenting, product safety, technology, and more for various publications.