5 of the Healthiest Fish to Eat—and 5 to Limit

Fish are a lean, healthy source of protein—and the oily kinds, such as salmon, tuna, sardines and mackerel, deliver those heart- and brain-healthy omega-3 fats. The Dietary Guidelines for Americans recommends adults eat 8 ounces of seafood per week (based on a 2,000-calorie diet).

There's also concern about the environment—and choosing seafood that's sustainable. So, if you often stand at the fish counter a little perplexed and wondering what's good for yourself and the planet, we can help. We've done research to find the best fish to eat when it comes to sustainability, mercury content and nutritional benefits.

5 of the Healthiest Fish to Eat

1. Pacific Chub Mackerel

The gear used to catch types of mackerel is efficient and not likely to cause major habitat destruction, a reason this guy is an ocean-friendly choice, according to the National Oceanic and Atmospheric Administration (NOAA). This strong-flavored fish is high in heart-healthy omega-3s, a good source of protein—delivering about 16 grams in 3 ounces—and pairs well with bold seasonings. The Food and Drug Administration recommends avoiding King mackerel, due to mercury; Pacific chub mackerel is a best choice.

2. Salmon, Wild-Caught (including canned)

Most farmed-raised and wild-caught salmon is relatively low in mercury and other contaminants, according to Washington State Department of Health. Wild-caught Alaska salmon produces fewer greenhouse gas emissions than farmed Norwegian salmon, making it better for the environment, according to a 2023 study published in Science of the Total Environment.

To give you an idea of how well-managed Alaska's salmon fisheries are, consider this: Biologists are posted at river mouths to count how many wild fish return to spawn. If the numbers begin to dwindle, the fishery is closed before it reaches its limits, as was done recently with some Chinook fisheries. This close monitoring, along with strict quotas and careful management of water quality, means Alaska's wild-caught salmon are more sustainable than just about any other salmon fishery.

From a nutrition standpoint, farmed-raised and wild-caught salmon have just about the same heart-healthy omega-3 fats. Buying salmon in a can is a more affordable way to get this healthy seafood in your diet. Canned salmon is not just a great source of omega-3 fats, it is one of the best sources of nondairy calcium. A 3-ounce serving has 241 milligrams (most adults need between 1,000 to 1,200 mg per day, according to the National Institutes of Health). Canned wild salmon is typically sockeye or pink from Alaska, but you'll want to check the label to make sure.

3. Sardines, Wild-Caught (including canned)

The tiny, inexpensive sardine is making it onto many lists of superfoods, and for good reason. It packs nearly 300 mg of omega-3 fats per 3 ounces and is one of the very few foods that's naturally high in vitamin D. It's also one of the few foods naturally high in calcium, packing 25% of your daily needs per serving. Other fish, like herring, pilchards and sprat, are in the same family as sardines.

Quick to reproduce, Pacific sardines have rebounded from both overfishing and a natural collapse in the 1940s. Get a taste for sardines in our delicious Lemon-Garlic Sardine Fettuccine that even sardine skeptics might enjoy.

4. Rainbow Trout (and some types of Lake)

Rainbow trout (also referred to as steelhead trout), is one of the best fish to eat when it's farmed in the U.S. or in indoor recirculating tanks, according to Monterey Bay Aquarium Seafood Watch. Trout ranks just under canned pink salmon when it comes to omega-3 fats and supplies potassium, selenium and vitamin B6 while offering more than a day's worth of vitamin B12.

Lake trout is a great alternative when it's sourced from the right places. Seafood Watch advises buying lake trout caught in the Great Lakes, specifically Lake Superior's Michigan and Minnesota waters, while avoiding trout that was caught from Wisconsin's Lake Superior waters.

5. Herring

Herring is a Nordic Diet staple—it has a higher omega-3 content than sardines, trout and mackerel at more than 1,400 mg per 3 ounces. It's also an excellent source of vitamin D and selenium. You'll typically find herring that has been canned, cured or smoked on restaurant menus, but it can also be eaten fresh.

Monterey Bay Aquarium Seafood Watch recommends buying U.S. Atlantic herring caught with purse seines or California herring caught with set gill nets. Befriend your local fishmonger, they will help you figure out the sourcing methods for your desired fish. Try our Scandinavian Pickled Herring Bites as an appetizer at your next get-together.

5 Fish to Limit

A number of environmental organizations have advocated taking several fish off the menu. The large fish listed below are just five examples EatingWell chose to highlight: popular fish that are both depleted and, in many cases, carry higher levels of mercury and polychlorinated biphenyls (PCBs). Mercury and PCBs are referred to as "legacy pollutants" and have been found to cause serious health issues in humans. The Food and Drug Administration (FDA) also provides advice on which fish to avoid due to mercury levels.

1. North Atlantic Swordfish

NOAA indicates that swordfish is a sustainable choice when it comes to seafood. However, swordfish is on the FDA's list of fish to avoid for being high in mercury, which is dangerous for those who might become pregnant, those who are pregnant or breastfeeding, and it is not recommended for young children.

2. Orange Roughy

This fish lives a long life but is slow to reproduce, making it vulnerable to overfishing. The orange roughy is on the FDA's list of fish to avoid due to high levels of mercury.

3. Salmon, Farmed in Pens (Atlantic)

Most farmed salmon are raised in tightly packed, open-net pens often rife with parasites and diseases that threaten the wild salmon trying to swim to their ancestral spawning waters. Open-net-farmed salmon are often given antibiotics to combat diseases, and their food and waste pollute the ocean. Freshwater-farmed salmon have earned a "Best Choice" status from Monterey Bay Aquarium Seafood Watch and some open-net systems are rated as "Good Alternatives." Consumer pressure may encourage more farms to continue to adopt better practices.

4. Mahi-Mahi (Costa Rica, Guatemala & Peru)

Imported, longline mahi-mahi, or dolphinfish, is rated as one of the least eco-friendly fish by the Monterey Bay Aquarium Seafood Watch. There is concern about bycatch, including sea turtles, seabirds and sharks, getting tangled in the fishing gear when mahi-mahi is fished. However, mahi-mahi caught in the U.S. and Ecuador with troll lines is ranked under "Good Alternative" by Seafood Watch and is the better choice if you're hankering for this particular fish.

5. Halibut, Wild-Caught (Atlantic)

This fish grows and matures slowly (living as long as 50 years), so it is susceptible to overfishing. Consequently, because of the depletion of Atlantic halibut populations, the U.S. prohibits commercial harvest of this breed found in the North Atlantic Ocean, and Seafood Watch rates it "Avoid." Pacific halibut is a good alternative, as it comes from well-managed fisheries with little habitat damage and low rates of other marine life being caught as bycatch.