Safety & Science
Mercury in Seafood: Facts, Myths & Safety Guide
How to read mercury risk by species, why salmon sits at the safe end, and what the FDA actually recommends.
This guide is for educational purposes only and is not a substitute for professional medical advice. The information presented is based on published data from the U.S. FDA, EPA, and peer-reviewed research. If you are pregnant, nursing, or have specific health concerns about mercury exposure, consult your physician or a registered dietitian for personalized guidance.
Key Takeaways
- Salmon is among the lowest-mercury fish: fresh and frozen salmon average 0.022 ppm in FDA testing (FDA 1990–2012 table), about 45 times below FDA’s 1 ppm action level.
- Mercury levels vary dramatically by species — choosing the right fish matters far more than avoiding fish altogether.
- Peer-reviewed research consistently shows that the health benefits of eating low-mercury fish outweigh the risks of trace mercury exposure.
- The FDA recommends 2–3 servings of low-mercury fish per week for adults, including pregnant women.
- Larger, longer-lived predatory fish (swordfish, shark, king mackerel) accumulate the most mercury through biomagnification.
- Cooking does not reduce mercury — the single most effective strategy is choosing low-mercury species.
1. What Is Mercury in Seafood?
Mercury is a naturally occurring heavy metal found throughout the Earth's crust, water, and atmosphere. The concern with mercury and seafood centers on one specific form — methylmercury — which can accumulate in fish tissue over time.
How Mercury Enters the Environment
Natural Sources
Volcanic eruptions, weathering of mercury-bearing rock, forest fires, and geothermal activity release mercury into the atmosphere. These natural processes account for roughly one-third of current atmospheric mercury.
Industrial Sources
Coal-fired power plants, cement production, artisanal gold mining, and industrial waste are the largest human-caused contributors. The EPA estimates human activity has increased atmospheric mercury 3–5x above natural levels.
Once airborne, mercury falls into waterways through rainfall. In aquatic environments, bacteria convert inorganic mercury into methylmercury — the organic form that readily binds to protein in fish muscle tissue.
Bioaccumulation & Biomagnification
Fish absorb methylmercury from water and food. Because it binds tightly to protein, mercury is not easily eliminated. The longer a fish lives, the more mercury it accumulates (bioaccumulation). At each step up the food chain, mercury concentrations multiply (biomagnification) — apex predators like swordfish can have concentrations 1 million to 10 million times higher than surrounding water.
This is why wild salmon (lifespan: 2–7 years, feeds on plankton/krill) has vastly less mercury than swordfish (lifespan: up to 15 years, feeds on large fish).
Methylmercury vs. Elemental Mercury
Elemental Mercury (Hg°)
Liquid metal found in old thermometers. Dangerous when inhaled as vapor, but poorly absorbed through the digestive tract. This is not the form found in fish.
Methylmercury (CH₃Hg)
The organic form created by bacteria in aquatic environments. Readily absorbed through the gut. This is the form measured by the FDA and the form that matters for seafood safety.
Most of the mercury in fish is methylmercury. FDA notes that mercury is found throughout the tissue in fish, so cleaning or cooking will not reduce it.[8]
One related question we get often: is salmon skin safe to eat? Yes — salmon is one of the lowest-mercury fish to begin with, so mercury is not a reason to skip the skin.
2. How Mercury Is Measured
Parts Per Million (ppm) Explained
Mercury in fish is measured in parts per million (ppm) — milligrams of mercury per kilogram of fish tissue. One ppm is equivalent to one second in 11.5 days, or one penny in $10,000. Fresh and frozen salmon, at an FDA average of 0.022 ppm, contain just 0.022 milligrams of mercury per kilogram — an extraordinarily small amount.
FDA Action Level & EPA Reference Dose
The threshold for FDA enforcement action. Fresh/frozen salmon averages 0.022 ppm — about 45x below this level.
The EPA reference dose includes a 10-fold uncertainty factor to allow for differences among people.
FDA/EPA advice: 2–3 servings (8–12 oz) a week of Best Choices such as salmon.
EPA’s reference dose is 0.1 microgram of methylmercury per kg of body weight per day. For a 150-lb (68 kg) adult that is about 6.8 micrograms a day. At FDA’s salmon average (0.022 ppm), a 4-oz raw serving carries about 2.5 micrograms. The reference dose is not a serving target: FDA/EPA advice is 2–3 servings (8–12 oz) a week of Best Choices such as salmon.
Source: EPA IRIS — Methylmercury Reference Dose, 2001.[10]
How Testing Works: The FDA Mercury Monitoring Program
The mercury data cited throughout this guide comes from the FDA Mercury Monitoring Program, which has tested thousands of fish samples over decades. FDA inspectors purchase commercially available seafood from retail markets across the United States, analyze samples for total mercury using validated methods, and publish results as mean concentrations with sample sizes and ranges for each species. The database currently includes data for over 60 species.[1]
This monitoring program is the foundation for the FDA/EPA “Advice about Eating Fish” (revised October 2021; first issued January 2017, revised July 2019), which categorizes species into Best Choices (2–3 servings/week), Good Choices (1 serving/week), and Choices to Avoid.[2]
3. Mercury Levels by Species: The Complete Data Table
The table below is based on data from the FDA Mercury Monitoring Program, which has tested commercially available seafood across the United States over multiple decades. Mean mercury concentrations are measured in parts per million (ppm) of total mercury in edible tissue.[1]
The FDA and EPA jointly categorize species into three advisory tiers based on measured mercury levels. These tiers form the basis of federal fish consumption advice for all consumers, including pregnant women and young children.[2]
✅ Best Choices — Eat 2–3 Servings Per Week
Lowest mercury species. Safe for all populations, including pregnant women and children. One adult serving = 4 oz (113 g), measured before cooking.
⚠️ Good Choices — Eat 1 Serving Per Week
Moderate mercury species. During pregnancy and breastfeeding, and for children: 1 serving a week, and no other fish that week.
❌ Choices to Avoid
Highest mercury species. The FDA advises that pregnant women, nursing mothers, and young children avoid these species entirely.
| Species | Mean Mercury (ppm) | Range (ppm) | FDA Category | Servings/Week |
|---|---|---|---|---|
| ✅ Best Choices — Lowest Mercury (2–3 servings per week) | ||||
| Shrimp | 0.009 | ND–0.05 | Best Choice | 2–3/week |
| Sardines | 0.013 | ND–0.08 | Best Choice | 2–3/week |
| Tilapia | 0.013 | ND–0.08 | Best Choice | 2–3/week |
| Anchovies | 0.016 | ND–0.05 | Best Choice | 2–3/week |
| Salmon (fresh/frozen)FDA row covers wild and farmed salmon of all species | 0.022 | ND–0.19 | Best Choice | 2–3/week |
| Catfish | 0.024 | ND–0.31 | Best Choice | 2–3/week |
| Pollock | 0.031 | ND–0.78 | Best Choice | 2–3/week |
| Crab | 0.065 | ND–0.61 | Best Choice | 2–3/week |
| Squid | 0.024 | ND–0.07 | Best Choice | 2–3/week |
| Scallops | 0.003 | ND–0.03 | Best Choice | 2–3/week |
| Canned Light Tuna | 0.126 | ND–0.89 | Best Choice | 2–3/week |
| Cod | 0.111 | ND–0.99 | Best Choice | 2–3/week |
| Haddock | 0.055 | ND–0.20 | Best Choice | 2–3/week |
| Herring | 0.078 | ND–0.56 | Best Choice | 2–3/week |
| Crawfish | 0.033 | ND–0.05 | Best Choice | 2–3/week |
| ⚠️ Good Choices — Moderate Mercury (1 serving per week) | ||||
| HalibutAlso available from Popsie Fish Co | 0.241 | ND–1.52 | Good Choice | 1/week |
| Canned Albacore Tuna | 0.350 | ND–0.85 | Good Choice | 1/week |
| Chilean Sea Bass | 0.354 | ND–2.18 | Good Choice | 1/week |
| Sablefish (Black Cod) | 0.361 | 0.09–1.05 | Good Choice | 1/week |
| Grouper | 0.448 | 0.01–1.21 | Good Choice | 1/week |
| Yellowfin Tuna | 0.354 | ND–1.48 | Good Choice | 1/week |
| Mahi Mahi | 0.178 | ND–0.45 | Good Choice | 1/week |
| Snapper | 0.166 | ND–1.37 | Good Choice | 1/week |
| Bluefish | 0.368 | 0.09–1.45 | Good Choice | 1/week |
| ❌ Choices to Avoid — Highest Mercury | ||||
| Bigeye Tuna | 0.689 | 0.13–1.82 | Avoid | Avoid |
| King Mackerel | 0.730 | 0.23–1.67 | Avoid | Avoid |
| Orange Roughy | 0.571 | 0.27–1.12 | Avoid | Avoid |
| Marlin | 0.485 | 0.10–0.92 | Avoid | Avoid |
| Shark | 0.979 | ND–4.54 | Avoid | Avoid |
| Swordfish | 0.995 | ND–3.22 | Avoid | Avoid |
| Tilefish (Gulf of Mexico) | 1.123 | 0.65–3.73 | Avoid | Avoid |
All mercury values in this table are from the FDA Mercury Monitoring Program database, which compiles results from FDA laboratory analyses of commercially distributed fish and shellfish. Mean concentrations represent arithmetic means of all samples tested. "ND" indicates non-detectable levels below the analytical limit of detection. Ranges are the lowest and highest single samples FDA reported.
Source: U.S. FDA. Mercury Levels in Commercial Fish and Shellfish (1990–2012). Updated 2022.[1]
What Does This Mean for Your Weekly Menu?
The FDA counts an adult serving as 4 ounces (113 grams) of fish measured before cooking; for children ages 4–7 it is about 2 ounces (57 grams). If you choose species from the "Best Choices" category — like wild salmon, shrimp, pollock, or cod — you can safely enjoy 2–3 servings per week. That is 8–12 ounces of fish per week, which aligns with the Dietary Guidelines for Americans.[2]
4. Why Wild Alaska Salmon Is One of the Safest Fish
Among all commercially available seafood, salmon consistently ranks among the very lowest in mercury contamination. This is not a marketing claim — it is a measurable, well-documented fact supported by decades of FDA monitoring data. Several biological and environmental factors explain why.
Short Lifecycle = Less Accumulation Time
Pacific salmon species have relatively short lifespans compared to high-mercury fish. Most wild salmon live just 2 to 7 years before completing their lifecycle. Compare that to swordfish (up to 15 years), shark (20–30+ years), or orange roughy (up to 150 years). Since mercury accumulates over a fish's entire life, shorter-lived species simply have less time to build up significant levels.
Low on the Food Chain
Wild salmon are not apex predators. They feed primarily on plankton, krill, and small schooling fish — organisms that are at the bottom of the marine food chain and carry very little mercury. This means salmon experience far less biomagnification than species like tuna, swordfish, or shark that feed on large fish high on the food chain.
Clean, Cold Waters
The wild salmon harvested by Popsie Fish Co comes from Bristol Bay, Alaska — one of the most pristine marine ecosystems on Earth. These waters are far removed from major industrial pollution sources. Bristol Bay is home to the largest wild sockeye salmon run in the world and has been sustainably managed for decades.
Does Mercury Differ by Salmon Species?
FDA does not test salmon by species, and it does not report wild and farmed salmon separately. All fresh/frozen salmon averages 0.022 ppm and canned salmon 0.014 ppm — both far inside FDA’s “Best Choices” limit of 0.15 ppm.[1][2]
Fresh/frozen salmon’s mean mercury level (0.022 ppm) is about 45 times lower than swordfish (0.995 ppm) and about 51 times lower than Gulf of Mexico tilefish (1.123 ppm in FDA’s 1990–2012 table). Ounce for ounce, you would need about 45 servings of salmon to take in the mercury in a single serving of swordfish.
Data: FDA Mercury Monitoring Program.[1]
Wild vs. Farmed Salmon: Mercury Comparison
Both wild and farmed salmon are low in mercury; FDA does not report them separately. For other contaminants, a 2004 study in Science (Hites et al.) found organochlorine contaminants, including PCBs, significantly higher in farmed salmon than in wild; farm feeds have changed since, so it may not reflect farmed salmon today. For a comprehensive comparison, see our Wild-Caught vs. Farm-Raised Salmon Guide.
5. The Bigger Risk: NOT Eating Fish
One of the most important — and least discussed — aspects of the mercury conversation is this: for most people, the health risk of avoiding fish entirely is greater than the risk of trace mercury exposure from low-mercury species. This is not opinion; it is the conclusion of multiple large-scale studies published in leading medical journals.
What the Research Shows
In 2007, Hibbeln and colleagues published a study in The Lancet that followed nearly 12,000 pregnant women and their children. The key finding: eating more than 12 ounces (340 g) of seafood per week during pregnancy was associated with better developmental outcomes in children. Children of mothers who ate no seafood were more likely to score in the lowest quarter for verbal IQ (odds ratio 1.48) than children of mothers who ate more than 12 ounces a week.
Hibbeln JR, et al. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study). The Lancet. 2007;369(9561):578-585.[3]
A comprehensive review by Mozaffarian and Rimm published in the Journal of the American Medical Association (JAMA) concluded that for major health outcomes, the benefits of moderate fish consumption (1–2 servings per week) substantially outweigh the risks. Eating fish 1–2 times per week was associated with a 36% lower risk of death from coronary heart disease. The authors specifically noted that concerns about mercury should not discourage fish consumption.
Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA. 2006;296(15):1885-1899.[4]
The Institute of Medicine (now the National Academy of Medicine) reviewed the totality of evidence on seafood safety and nutrition and concluded that the health benefits of eating seafood outweigh the chemical risks for the general population. For women who are or may become pregnant or are breastfeeding, the IOM said a reasonable intake is two 3-ounce cooked servings a week, and that they can safely eat 12 ounces a week. The Dietary Guidelines and FDA advise 8–12 ounces a week of lower-mercury fish.
IOM (Institute of Medicine). Seafood Choices: Balancing Benefits and Risks. Washington, DC: The National Academies Press; 2007.[5]
The Lost Omega-3s: What You Miss by Avoiding Fish
When people avoid fish out of mercury fear, they lose access to one of the most important nutrients in the human diet: long-chain omega-3 fatty acids (EPA and DHA). These essential fats are critical for:
Brain Development
DHA is especially concentrated in the brain and retina. It accumulates most rapidly during the third trimester of pregnancy, and brain DHA keeps building through the first 2 years after birth.
Heart Health
Long-chain omega-3 supplements lower triglycerides, and eating fish 1–2 times a week is associated with a lower risk of dying from coronary heart disease. The American Heart Association recommends 2 servings of fish a week (3 oz cooked each).
Eye & Joint Health
DHA is especially concentrated in the retina. In trials, 3–4 months of omega-3 supplements reduced patient-reported joint pain and morning stiffness in rheumatoid arthritis and related joint pain (Goldberg & Katz, 2007).[11]
For a deeper exploration of these benefits, see our Health Benefits of Wild Salmon and Complete Omega-3 Guide.
Net Health Analysis: A Risk-Benefit Framework
The research consistently shows that when you weigh the documented risks of trace mercury exposure from low-mercury fish against the documented risks of inadequate omega-3 intake, the calculus is clear:
Risks of Low-Mercury Fish Consumption
- Trace methylmercury exposure (well below EPA reference dose for Best Choice species)
- FDA/EPA advise 2–3 servings a week of Best Choices, even during pregnancy
Risks of Avoiding Fish Entirely
- Missing the lower coronary death risk linked to eating fish 1–2 times a week (36% in one major review)
- Inadequate DHA for brain development (especially in pregnancy)
- Higher odds of low verbal IQ scores in children whose mothers ate no seafood in pregnancy (observational)
- Lost anti-inflammatory benefits
- Missing selenium, vitamin D, iodine, and high-quality protein
The Bottom Line
For the vast majority of people — including pregnant women — the question is not whether to eat fish, but which fish to choose. Selecting low-mercury species like wild salmon, shrimp, pollock, and sardines delivers tremendous health benefits with negligible mercury risk. The FDA and EPA's joint advisory explicitly encourages 8–12 ounces of low-mercury fish per week, even for pregnant and nursing women.[2]
6. Contaminants Beyond Mercury
While mercury gets the most public attention, it is not the only contaminant found in seafood. A complete picture of seafood safety includes PCBs, dioxins, microplastics, and other industrial chemicals.
PCBs & Dioxins
Polychlorinated biphenyls (PCBs) and dioxins are persistent organic pollutants that accumulate in fat tissue. They are of particular concern in fatty fish and have been linked to cancer, immune disruption, and endocrine effects at high exposure levels.
Wild vs. Farmed: PCB Levels
A widely cited 2004 study in Science (Hites et al.) that analyzed more than 2 metric tons of salmon found organochlorine contaminants, including PCBs, significantly higher in farmed salmon than in wild. European-raised salmon had the highest levels. The data reflect farm feeds of that era, and farm feeds have changed since, so the study may not reflect farmed salmon today.[6]
This does not mean farmed salmon is unsafe — FDA’s tolerance for PCBs in fish is 2 ppm, and both wild and farmed salmon fall under it.
Microplastics in Seafood
Microplastics (plastic particles smaller than 5mm) are an emerging concern in all food systems, including seafood. Current research findings include:
- Microplastics have been detected in a wide variety of seafood species, including fish, shrimp, and shellfish
- The gastrointestinal tract is the primary location of microplastic accumulation in fish; fillets (muscle tissue) contain significantly less than whole fish consumed with viscera
- The long-term health effects of dietary microplastic exposure in humans are not yet well understood, and research is ongoing
- Shellfish that are consumed whole (oysters, mussels) may represent higher exposure than fish fillets
For fish like salmon that are consumed as fillets (not whole), current evidence suggests microplastic exposure is relatively low. However, this is an active area of scientific investigation and recommendations may evolve as more data becomes available.
Antibiotics & Pesticides in Farmed Fish
Aquaculture operations frequently use antibiotics to manage disease in dense farming conditions and pesticides to control parasites like sea lice. While regulatory agencies set limits on residues in marketed fish, these chemicals are essentially absent from wild-caught species:
| Contaminant | Wild Alaska Salmon | Farmed Atlantic Salmon |
|---|---|---|
| Mercury (ppm) | 0.022 mean (all fresh/frozen salmon) | 0.022 mean (FDA does not report farmed and wild separately) |
| PCBs | Lower in a 2004 study (Hites et al.) | Significantly higher in that 2004 study; farm feeds have changed since |
| Dioxins | Lower in the same 2004 study | Higher in that 2004 study |
| Antibiotics | None | May contain residues |
| Pesticides | None | May contain residues (sea lice treatment) |
| Artificial coloring | None (natural astaxanthin) | Synthetic astaxanthin added to feed |
For a comprehensive comparison of wild and farmed salmon across all these factors, see our Wild-Caught vs. Farm-Raised Salmon: The Complete Guide.
7. How to Minimize Mercury Exposure
The single most effective way to manage mercury exposure from seafood is species selection. There is no cooking method, preparation technique, or supplement that removes mercury from fish once it has accumulated. Here are the evidence-based strategies that actually work.
1. Choose Low-Mercury Species
This is by far the most impactful step. Refer to the species table above and focus your seafood meals on "Best Choices" species: wild salmon, shrimp, pollock, sardines, anchovies, cod, tilapia, and catfish. These species deliver all the nutritional benefits of seafood with minimal mercury exposure.
2. Vary Your Species
Eating a variety of low-mercury fish species rather than the same fish every meal further reduces your exposure to any single contaminant. Variety also provides a broader spectrum of nutrients, since different fish species have different nutritional profiles. Rotating between salmon, cod, shrimp, and sardines throughout the week is an excellent strategy.
3. Follow FDA Serving Guidelines
FDA/EPA Advice about Eating Fish (revised October 2021): Recommended Servings
Adults: 2–3 servings (8–12 oz) of low-mercury fish per week.
Pregnant & nursing women: 2–3 servings (8–12 oz) a week from the Best Choices list, or 1 serving from the Good Choices list (such as halibut or sablefish) and no other fish that week. FDA notes moderate scientific evidence that eating fish in pregnancy can help a baby’s cognitive development.
Children (ages 1–11): 2 servings a week from the Best Choices list, sized for age: about 1 oz at ages 1–3, 2 oz at 4–7, 3 oz at 8–10 and 4 oz at 11.
Everyone: Avoid the 7 highest-mercury species (swordfish, shark, king mackerel, tilefish from the Gulf, bigeye tuna, marlin, orange roughy).[2]
4. Understand Selenium's Protective Role
An increasingly recognized factor in mercury toxicity is selenium. Mercury's primary mechanism of harm is its ability to bind to and inactivate selenium-dependent enzymes in the body. When a fish contains more selenium than mercury (a high selenium:mercury molar ratio), the selenium can counteract mercury's toxic effects.
Most ocean fish contain selenium in excess of mercury, providing a natural protective buffer. Wild salmon is particularly rich in selenium, with concentrations that far exceed its mercury content. In a 2010 review, Ralston and Raymond described how methylmercury damages the body by tying up selenium-dependent enzymes, and how adequate dietary selenium protects against that harm — so a fish’s selenium content, not just its mercury level, matters when judging seafood safety.
Ralston NVC, Raymond LJ. Dietary selenium's protective effects against methylmercury toxicity. Toxicology. 2010;278(1):112-123.[7]
Foods high in selenium include Brazil nuts, fish (especially tuna, halibut, and sardines), eggs, and sunflower seeds. However, the most elegant solution is simply eating selenium-rich, low-mercury fish like wild salmon — you get both the protective selenium and the beneficial omega-3s in one food.
5. Know What Does NOT Work
Several commonly believed mercury-reduction strategies are, unfortunately, ineffective:
Cooking Does NOT Remove Mercury
Methylmercury is tightly bound to the protein in fish muscle tissue. Grilling, baking, frying, steaming, or any other cooking method does not reduce mercury content. In fact, because cooking removes water, mercury concentrations per gram may actually increase slightly in cooked fish.
Soaking or Rinsing Does NOT Help
Unlike some water-soluble contaminants, methylmercury cannot be washed, soaked, or rinsed out of fish. It is chemically bound to the proteins and will remain until the protein itself is broken down.
The Actionable Summary
Mercury management is about species choice, not preparation method. Choose wild salmon and other low-mercury fish from the Best Choices list, eat 2–3 servings per week, avoid the 7 highest-mercury species, and enjoy the enormous health benefits with confidence. That is the entire strategy, and it matches FDA/EPA fish advice and the American Heart Association’s recommendation of two servings of fish a week.
8. Mercury Myths vs. Facts
Widespread misinformation has led many people to avoid fish entirely — a decision that may actually harm their health. Here are the most common myths, debunked with data.
Mercury levels vary by a factor of more than 100x between species. Shrimp averages 0.009 ppm while Gulf of Mexico tilefish averages 1.123 ppm in FDA’s 1990–2012 table. The majority of commonly consumed species fall into the FDA's "Best Choices" category with very low mercury levels.[1]
Canned light tuna (skipjack) averages 0.126 ppm — a Best Choice at 2–3 servings/week. Canned albacore averages 0.350 ppm — a Good Choice at 1/week. The species matters more than the form.[1][2]
The opposite of current guidelines. The FDA/EPA recommend pregnant women eat 8–12 oz of low-mercury fish per week. In the Avon Longitudinal Study, eating more seafood in pregnancy was associated with better developmental outcomes in children.[2][3]
Methylmercury is chemically bound to protein and cannot be removed by any cooking method. Mercury per gram may actually increase slightly after cooking due to water loss. Species selection is the only effective strategy.[8]
FDA does not report mercury separately for wild and farmed salmon (0.022 ppm for all fresh/frozen salmon). A 2004 study found organochlorine contaminants, including PCBs, significantly higher in farmed salmon than in wild (farm feeds have changed since), and farmed fish may carry antibiotic and pesticide residues.[1][6]
Fish oil supplements are low in mercury but miss the complete nutritional matrix of whole fish: high-quality protein, selenium, vitamin D, iodine, and B12. Clinical evidence for cardiovascular benefits is stronger for whole fish than supplements alone.[4]
9. Frequently Asked Questions
Salmon is one of the lowest-mercury fish: fresh/frozen salmon averages 0.022 ppm in FDA testing. FDA/EPA advice is set by the week, not the day: 2–3 servings (8–12 oz) a week of Best Choices such as salmon.[1][2]
Fresh/frozen salmon averages 0.022 ppm vs. canned light tuna at 0.126 ppm, canned albacore at 0.350 ppm, and bigeye tuna at 0.689 ppm. Salmon has ~6x less mercury than light tuna and ~31x less than bigeye.[1]
Yes. The FDA, EPA, and ACOG recommend 8–12 oz of low-mercury fish per week during pregnancy for fetal brain development. Choose Best Choices species and avoid the 7 highest-mercury species. See our Seafood & Pregnancy Guide.[2][3]
Clinical mercury poisoning from fish is extremely rare and requires sustained high-mercury species consumption over extended periods. Symptoms include tingling in extremities, impaired vision, coordination difficulty, and cognitive changes. A blood test can measure your levels.[9]
No. Methylmercury is bound to protein and is not removed by grilling, baking, frying, or any cooking method. Choosing low-mercury species is the only effective approach.[8]
FDA does not report wild and farmed salmon separately; together, fresh/frozen salmon averages 0.022 ppm. A 2004 study found organochlorine contaminants, including PCBs, significantly higher in farmed salmon (farm feeds have changed since), and farmed fish may contain antibiotic residues. See our Wild vs. Farmed comparison.[1][6]
Gulf of Mexico tilefish (1.123 ppm), swordfish (0.995 ppm), shark (0.979 ppm), king mackerel (0.730 ppm), and bigeye tuna (0.689 ppm). The FDA advises pregnant women and children to avoid these entirely.[1][2]
The FDA/EPA recommend 2–3 servings (8–12 oz) of low-mercury fish per week for adults, including pregnant women. For “Good Choices” such as halibut or sablefish, the advice is 1 serving a week — and during pregnancy, breastfeeding and for children, no other fish that week.[2]
Yes. FDA and EPA advise children ages 1 to 11 eat 2 servings a week from the “Best Choices” list, sized for age: about 1 oz at ages 1–3, 2 oz at 4–7, 3 oz at 8–10 and 4 oz at 11. Wild salmon, shrimp, and cod are excellent choices.[2]
Trace levels of arsenic, cadmium, and lead may be present but at very low concentrations. The arsenic in seafood is predominantly organic arsenic (far less toxic).
Low-Mercury Recipe Ideas
All recipes feature FDA "Best Choices" fish — safe for 2–3 servings per week.
Garlic Butter Baked Wild Salmon
Fillets baked at 400°F with garlic, lemon, and herbs.
Teriyaki Salmon Rice Bowls
Pan-seared salmon over rice with avocado and teriyaki glaze.
Wild Salmon Patties
Crispy pan-fried cakes with Dijon and lemon-dill yogurt.
Garlic Shrimp Stir-Fry
Quick stir-fry with snap peas and ginger-garlic sauce.
Herb-Crusted Baked Cod
Flaky cod with panko-parmesan crust. Kid-friendly.
Mediterranean Sardine Toast
Sardines on sourdough with olive oil, tomatoes, and basil.
Choose the Safest Wild Seafood
Wild sockeye from Bristol Bay — salmon has some of the lowest mercury levels of any fish. Sustainably harvested, flash-frozen, shipped direct to your door.
Shop Wild Alaska Salmon →10. References & Citations
- [1] U.S. FDA. Mercury Levels in Commercial Fish and Shellfish (1990–2012). FDA.gov. Content current as of February 2022.
- [2] U.S. FDA & EPA. Advice about Eating Fish. FDA.gov. Revised October 2021 (first issued January 2017; revised July 2019).
- [3] Hibbeln JR, et al. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study). The Lancet. 2007;369(9561):578-585. PubMed.
- [4] Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health. JAMA. 2006;296(15):1885-1899. PubMed.
- [5] Institute of Medicine. Seafood Choices: Balancing Benefits and Risks. NAP; 2007. NAP.edu.
- [6] Hites RA, et al. Global assessment of organic contaminants in farmed salmon. Science. 2004;303(5655):226-229. PubMed.
- [7] Ralston NVC, Raymond LJ. Dietary selenium's protective effects against methylmercury toxicity. Toxicology. 2010;278(1):112-123. PubMed.
- [8] U.S. FDA & EPA. Questions & Answers from the FDA/EPA Advice about Eating Fish. FDA.gov.
- [9] Clarkson TW, et al. The toxicology of mercury. NEJM. 2003;349(18):1731-1737. PubMed.
- [10] U.S. EPA. IRIS: Methylmercury Reference Dose. 2001. EPA.gov/IRIS.
- [11] Goldberg RJ, Katz J. A meta-analysis of the analgesic effects of omega-3 polyunsaturated fatty acid supplementation for inflammatory joint pain. Pain. 2007;129(1-2):210-223. PubMed.
Last updated: October 2026. Mercury values checked against the FDA table (1990–2012); serving advice against FDA/EPA Advice about Eating Fish (revised October 2021).