Humans have eaten seafood for millennia. Today, about 1 billion people worldwide depend on fish as their primary source of animal protein, and health experts recommend fish as one of the best sources of anti-inflammatory omega-3 fats. Many dietary guidelines recommend eating at least two servings of fish each week.
Yet a number of factors now call into question whether eating seafood is truly healthy — for us or for our planet.
Earth’s oceans have gone from being rich with biodiversity to becoming polluted with waste and chemicals, home to floating islands of discarded plastic.
Because of overharvesting, many fish populations are under severe stress. “There are things in the ocean that make you despair,” says Charles Clover, cofounder and executive director of Blue Marine Foundation, a nonprofit dedicated to restoring oceans.
The number of overfished stocks has tripled in the last 50 years, according to the United Nations. One-third of the world’s fisheries are currently overfished, and 60 percent are fished to capacity. Illegal, unreported, and unregulated fishing — accounting for approximately one in five fish caught — are some of the most prevalent global crimes.
Yet some sustainability experts believe it’s not too late to reverse course. “Imagine if the sea had all the species in it that it used to and we had brought back nature within sight of our shores,” suggests Clover. “There are parts of the world where it has already happened or is happening.”
Many areas are already “achieving defensible, scientifically credible results in conservation,” he says. Smarter management policies, better collaboration between fishers and government, and heightened consumer awareness have all been shown to make a difference.
Such efforts helped rockfish return to San Francisco’s historic Fisherman’s Wharf, even after becoming so depleted that they were almost added to the endangered-species list. Since 2000, 47 U.S. federally managed fish stocks have been declared rebuilt.
Today, Florida researchers are working to return red snapper to the Atlantic Ocean. Conservationists worldwide are working to revitalize sturgeon populations through habitat restoration, fishing bans, repopulation of waterways, and connecting local communities with the historical, ecological, and cultural significance of these “dinosaur fish.”
Angler and tribal involvement in conservation efforts is also helping fisheries rebound. Efforts to restore Chinook salmon to the Snake River in the Pacific Northwest, for example, include cooperation between Native tribes, state and federal fish and wildlife services, and others.
The Shoshone-Bannock people have worked tirelessly to save the sockeye-salmon runs on Idaho’s portion of the Snake River. The strong cultural ties to salmon for certain Native communities have led some non-Indigenous people to wonder whether it’s best to avoid consuming salmon altogether — at least until populations rebound — or to eat only fish from Indigenous-owned salmon fisheries so the tribes can continue to restore the salmon population.
“It’s not just an animal; it’s not just a fish,” says tribal research biologist Sammy Matsaw, PhD. “There’s a whole people and culture that can be lost.”
This is just one example of the ethical complexities that now accompany a seafood meal. The choices are complicated. Still, many sustainable-food advocates believe that thoughtful fish consumption is part of the solution.
While some ocean-health advocates do advise against eating fish at all, Clover and others believe that that approach is too simplistic. If we don’t support those who are working to make seafood more sustainable for all, says Clover, “you undermine the economy of local places; you undermine the people who are looking after those areas.”
Far better to support their positive efforts than to treat the seafood industry as if all producers were the same.
Determining which fish are truly sustainable starts with asking questions like these.
Is there a sustainability difference between freshwater and saltwater fish?
Overfishing happens everywhere: local streams, the Great Lakes, and the sea. Both saltwater and freshwater harvests have increased dramatically in recent decades and show no signs of abating. As one species is overfished, fishers turn their efforts toward those that remain.
Sustainability efforts place a lot of focus on ocean stocks — but waterways are connected, so issues such as pollution, invasive species, and climate change affect all aquatic life.
Are some fishing methods more sustainable than others?
Commercial fishing employs a broad range of methods, only some of which are sustainable. The most sustainable methods have the smallest impact on other aquatic species and the environment. These include pole and line (an angler can quickly identify and release any unintended catch); spearfishing and harpooning; and trolling.
Floating fish traps and weirs are also sustainable methods, because fish can enter traps without risking entanglement, which is an issue with nets.
All these methods help minimize environmental damage and overfishing as well as bycatch, which is the accidental harvest of nontarget species, such as dolphins, turtles, and seabirds.
At the other end of the spectrum are methods that take an enormous toll on sea life and ocean health. These include bottom trawling and dredging, both of which involve dragging weighted nets across the sea floor. These methods damage habitat, sweeping up everything in their wake, and they lead to substantial bycatch.
Giant drift nets, which move with the current, also capture large numbers of nontarget species. The same is true for miles-long lines with multiple baited hooks; these attract many species, so bycatch is significant.
Are there labor issues in the fishing industry?
Seafood sustainability efforts also include creating safer, fairer conditions for those who work in the fishing industry. Human-rights abuses — including forced labor, trafficking, physical punishment, and insufficient food and water for workers — have been reported on vessels throughout the commercial-fishing industry.
One survey of workers in the fishing industry in the Gulf of Thailand found that approximately 17 percent were working against their will and unable to quit.
One survey of workers in the fishing industry in the Gulf of Thailand found that approximately 17 percent were working against their will and unable to quit. Reports of labor exploitation have also come from fisheries in the United Kingdom and New Zealand.
As organizations document more of these abuses, large seafood companies have begun establishing codes of conduct for their suppliers, implementing improved traceability and inviting third parties to audit supply chains.
The safest bet is to buy seafood from small suppliers who share information about their supply chains.
How much does pollution affect seafood quality?
Many contaminants in our waters harm both aquatic and human health. These include microplastics, per- and polyfluoroalkyl substances (PFAS), and endocrine-active compounds that can mimic the effects of hormones.
One analysis found that fish throughout the world’s oceans are frequently contaminated with persistent organic pollutants from farming and industry. Although these substances were banned in 1977, heavily used compounds like DDT and PCBs (polychlorinated biphenyls) made their way into waterways and accumulated in sediment. Slow to break down, PCBs accumulate in the fatty tissues of fish and other animals.
Mercury is another concern; because it binds to proteins, this neurotoxin is often found in fish.
Mercury is another concern; because it binds to proteins, this neurotoxin is often found in fish. To reduce the risk of mercury exposure, health experts recommend avoiding larger fish species, including shark, swordfish, king mackerel, and tilefish.
To reduce your exposure to all toxins, vary your fish choices. Opt for panfish (such as stream trout, smelt, and perch) that eat insects rather than other fish; smaller gamefish (such as walleye, lake trout, and bass) that likely haven’t accumulated as many toxins in their systems; and leaner fish (such as yellow perch, sunfish, and crappie).
It’s also helpful to eat fewer fatty fish, like lake trout, or those that feed on lake and stream bottoms, like catfish and carp. Properly cleaning fish, as well as preparing it by broiling, grilling, or baking, may help drain away some of the fat, where contaminants accumulate.
You can always consult one of the available guides to find low-mercury fish. The Environmental Working Group’s Good Seafood Guide provides a calculator that considers a person’s age, weight, and risk of heart disease and offers sustainability rankings for seafood. The Environmental Defense Fund (EDF) Seafood Selector also offers information on mercury risks and sustainability ratings.
What seafood should I avoid?
There are many reasons you might want to steer clear of eating a particular species: It may be overfished, high in mercury, or endangered. It might be caught in ways that are harmful to workers or the aquatic environment.
Likewise, which seafood is a good choice depends on a variety of factors, from the current status of wild stocks to where farmed seafood originates, because countries have differing regulations. And most of these conditions change routinely.
Below are some fish that frequently appear on their “best avoided” lists.
- Atlantic Halibut: Wild Atlantic halibut often has high levels of mercury. Pacific halibut is still a good choice.
- Atlantic Salmon: Although Pacific salmon are usually wild caught, most Atlantic salmon are farmed; they are typically raised in offshore floating cages in the Canadian Atlantic, Chile, Norway, and Scotland. They suffer from problems similar to those of livestock in large-scale farms on land: They live in crowded quarters, contract illnesses that require antibiotics, and are fed other fish that are harvested en masse.
- Catfish, imported: Imported catfish undermines the production of U.S. farmed catfish, which tends to be responsibly farmed, using minimal antibiotics.
- Chilean Sea Bass: These large, slow-growing fish have been brought to the brink of extinction.
- Cod: Stocks of Atlantic cod collapsed from overfishing in the mid-1990s and have not recovered. Pacific cod from Japanese fisheries are caught by trawls and are overfished. Alaskan cod, however, is well managed.
- Crab, imported: Crab harvesting in the United States gets a high sustainability rating from the EDF Seafood Selector, but the majority of imported red and blue king crabs are harvested unsustainably by one poorly managed Russian fishery.
- Freshwater Eel: Beloved by sushi fans, unagi eel rates high in toxins. (To learn more about the best and worst choices for sushi, check out the EDF Seafood Selector.)
- Mahi Mahi: This saltwater fish from Peru and Taiwan is typically caught with long lines that attract bycatch.
- Octopus: Most varieties of this highly intelligent species are overfished.
- Orange Roughy: Also overfished, orange roughy take up to two decades to reach maturity; populations require a long time to rebound.
- Pollock: It matters where it comes from — most Atlantic and Alaskan pollock is sustainable, but Canadian and Russian fishers use gill nets, trawls, and long lines that produce substantial bycatch.
- Shark: Overfishing has been a disaster for shark populations as well as oceans, because these predators play an important role in maintaining biodiversity. Shark often contains high levels of mercury.
- Shrimp: Farm shrimp ponds are replacing mangroves in many areas, contributing to shoreline erosion and worsening the impact of tsunamis. Fresh shrimp is often caught by trawls using forced labor. Bycatch is also an issue, with 2 to 10 pounds of other fish caught for every pound of shrimp. Unless you can get wild-caught shrimp in season near one of the U.S. coasts, it’s best to steer clear.
- Spiny Lobster, imported: This crustacean often comes from Belize, Brazil, Honduras, and Nicaragua, where regulations and stock management are weak.
- Squid: Squid fisheries are largely unregulated and not well studied. Squid are also typically caught with bottom and midwater trawls, with substantial bycatch.
- Swordfish: This grand saltwater fish often contains high levels of mercury and is typically caught with longlines.
- Tuna: Tuna — including albacore, bluefin, skipjack, and yellowfin — can accumulate high mercury content, and it is typically unsustainably caught and overfished. Japanese hamachi (Pacific yellowtail tuna), beloved by sushi fans, often contains high levels of toxins. Pole-caught tuna is much more sustainable.
How can I find sustainable seafood?
Again, the easiest route is to use a guide. The Monterey Bay Aquarium Seafood Watch and EDF Seafood Selector are useful for checking the sustainability of seafood species when you’re shopping or dining out. Here are some other strategies to use.
Shrimp, salmon, pollock, cod, crab, canned tuna, and clams make up the majority of seafood consumed in the United States. Choosing less-mainstream fish can help ease pressure on popular favorites and allow their stocks to rebound.
Try smaller, more abundant species.
Think anchovies, sardines, and mackerel, which are caught sustainably and also provide plenty of healthy omega-3 fats.
Still, moderation matters.
Although smaller fish are more sustainable, they’re also central in many subsistence and traditional diets, and they’re becoming increasingly unavailable to those who rely on them daily.
“If fish that were once caught in sustainable quantities by local fishers for local eaters are now being harvested by factory vessels and shipped worldwide to be eaten by wealthy people, local food security is disrupted,” notes food journalist and cookbook author Mark Bittman in Animal, Vegetable, Junk: A History of Food, From Sustainable to Suicidal.
Look for the country of origin.
A 2016 survey of 28 countries found that countries with effective fishery management generally produced healthy fish stocks, while countries without fishery management featured declining stocks. The best-performing fisheries were found in the United States and Iceland; the poorest were in the Philippines, Bangladesh, China, Brazil, Thailand, and Myanmar.
“The principal responsibility is with governments to make sure that the fish caught in their waters are caught sustainably without bycatch and in a way that means they’re not destroying the environment,” notes Clover. Shop at a fish market and ask where the catch originated. Or read labels for the origin.
Look for sustainable sourcing.
When you’re buying canned or frozen fish, look for companies that source seafood from fishers who use sustainable methods, such as pole-and-line fishing or reef nets, as well as selective harvesting.
Buy a share in a community-supported fishery (CSF).
Like their terrestrial kin, community-supported agriculture, CSFs allow local and small-scale anglers to get a better price for their product, promote environmental stewardship, emphasize sustainable fishing practices, and protect local and regional food systems. One study found that CSFs emphasize abundant species not targeted by industrialized fisheries, encourage experimentation with lower-impact fishing methods, and help familiarize eaters with species that would otherwise be discarded.
Vote for legislators who support good fishing policy and habitat preservation. This is good for the ocean and the planet as well as recreational, subsistence, and commercial fishers. Visit the Marine Fish Conservation Network and Ocean Champions sites to learn more about the issues.
How to Catch a Fish
The following is a list of fishing methods that are sustainable — and some methods that are not.
There have always been simple and eco-friendly methods for capturing fish. Some traditional approaches include cast nets, still used by subsistence fishers worldwide, and reef nets, used today by Indigenous communities in areas like the U.S. Pacific Northwest.
Most commercial fishing is done using some of the following methods. To ensure what you’re buying is sustainable, look for methods that limit overfishing, minimize bycatch of other species, and don’t damage the environment.
While no approach is foolproof — even the most sustainable method won’t put fish back into overfished waters — there are some methods that produce less damage than others.
Floating fish-trap and weir fishing — nets held in place with floats and anchors that allow fish to enter a series of more restrictive areas without coming into direct contact with the net. They can then be either harvested or released without being injured or entangled.
Pole-and-line fishing, fly fishing, jigging, and rod-and-reel fishing — use of a single rod with one hook baited to catch fish. An angler can quickly remove unwanted catches from the hook after capture, minimizing bycatch, environmental damage, and overfishing.
Spearfishing, hand-diving, and harpooning — Spearfishing (using handheld spears) and harpooning (using barbs fired from a gun) are traditional methods used for catching larger species, like swordfish. Hand-diving is typically used for smaller species, like scallops, which are simply gathered by hand, allowing the fisher to leave younger fish out to keep developing. Bycatch is almost nonexistent with these methods, since they all target individual fish.
Trolling — a type of pole fishing in which an individual weighted line and single hook loaded with an artificial lure or live bait is towed from a moving boat. Bycatch, environmental damage, and overfishing are minimal in this method.
Purse-Seining — A net (seine) with floats at the top and weights at the bottom is hung vertically in the water, encircling schooling fish, and a drawstring is pulled to trap them. While this method does not harm the seafloor, it can capture species indiscriminately, leading to high levels of bycatch of marine life like sea turtles, dolphins, and humpback whales. It can also lead to overfishing.
Trawling — The Marine Conservation Institute calls trawling the world’s most destructive type of fishing. A boat drags a weighted net behind it to catch fish or shrimp that live in, on, or just above the seafloor. Since over 98 percent of marine animal species live in this area, bycatch is heavy in this method. Trawling also damages the seabed, upsetting the balance of ocean ecosystems. Since the ocean is also one of the Earth’s largest carbon sinks, disrupting the seafloor releases tons of carbon into the atmosphere.
Dredging — A mesh bag is dragged along the seafloor to capture clams, scallops, and oysters. Like trawling, this method damages the seafloor and captures fish, sponges, and other marine life that tend not to survive capture.
Drift-net fishing — These long, mobile nets are placed in the water and drift with the current. They can capture a large amount of fish, leading to overfishing. They also generate a high amount of bycatch.
Long-lining — One very long central line (up to 50 miles in some cases) with hooks dangling from it is used to catch fish near the ocean surface or just off the ocean floor. Long-lining attracts lots of species, so bycatch can be significant.
This article originally appeared as “In Search of Sustainable Seafood” in the June 2022 issue of Experience Life.