Is Keta Salmon High in Mercury? Understanding the Risks

December 21, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), the average mercury concentration in fresh/frozen salmon is just 0.022 parts per million (ppm), which is considered very low. As a wild, Alaskan salmon species, Keta falls into this low-risk category, making it a safe and healthy seafood choice for regular consumption.

Quick Summary

Keta salmon has very low levels of mercury, significantly less than larger predatory fish, and is considered a safe seafood option by health authorities like the FDA. Its short lifespan and position lower on the food chain contribute to minimal mercury accumulation. Keta is also a great source of lean protein and omega-3 fatty acids.

Key Points

Low Mercury Content: Keta salmon has very low mercury levels due to its diet of smaller fish and its relatively short lifespan, placing it low on the marine food chain.
FDA Confirmed Safety: The FDA and EPA categorize salmon, including Keta, as a "Best Choice" seafood, recommending 2-3 servings per week, even for pregnant women and children.
High in Omega-3s and Protein: Despite being leaner than other salmon, Keta is a fantastic source of lean protein and heart-healthy omega-3 fatty acids (EPA and DHA).
Wild vs. Farmed Differences: While both types are low in mercury, wild-caught Alaskan Keta generally has even lower overall contaminants compared to some farmed varieties, though both are safe.
Nutrient-Dense: Keta salmon is also rich in essential nutrients like Vitamin B12 and selenium, offering significant health benefits alongside its low mercury profile.

Keta Salmon's Position on the Mercury Spectrum

Unlike large, long-lived predatory fish such as swordfish and shark, Keta salmon has a much shorter lifespan and feeds on smaller fish, crustaceans, and plankton. This places it significantly lower on the marine food chain, which is the primary reason for its minimal mercury levels. Mercury, and specifically the potent neurotoxin methylmercury, accumulates through a process called biomagnification, where concentrations increase as they move up the food chain. A wild Keta's life cycle typically lasts between two and eight years, which does not allow sufficient time for substantial mercury accumulation.

Health agencies like the FDA and EPA categorize fish based on their mercury content to help consumers, particularly pregnant women and young children, make informed choices. Salmon is consistently placed in the "Best Choices" category, which allows for regular consumption of 2 to 3 servings per week. Specific testing on Keta salmon confirms its low mercury status. This provides peace of mind for anyone looking to incorporate more seafood into their diet without the worry of mercury exposure.

Wild vs. Farmed: Mercury Differences

While both wild-caught and farmed salmon are known to be low in mercury, there are some subtle differences. Research has shown that wild Alaskan salmon, which includes Keta, contains some of the lowest contaminants overall, including PCBs and mercury. The mercury concentration in farmed fish can sometimes be influenced by their diet, but generally, farmed salmon remains well within safety guidelines.

Studies have also explored the concept of "lipid dilution," where rapidly growing farmed salmon with higher fat content can have lower mercury concentrations per gram compared to their wild counterparts. However, it's important to remember that these are fine distinctions; the overarching fact is that all varieties of salmon, including Keta, are considered low-mercury options by public health officials.

The Nutritional Upside of Keta Salmon

Choosing Keta salmon offers numerous health benefits beyond its low mercury profile. This species is an excellent source of lean, high-quality protein, which is essential for building and repairing muscle tissue and promoting satiety. It also provides a valuable source of marine-derived omega-3 fatty acids, specifically EPA and DHA, which support brain function, heart health, and reduce inflammation.

Keta is also packed with important vitamins and minerals. It's particularly rich in Vitamin B12, which is crucial for nerve function and red blood cell production, and selenium, an antioxidant that supports immune health. Its relatively low fat content compared to other salmon species makes it a versatile ingredient for grilling, smoking, or roasting, appealing to those seeking a leaner protein source.

Comparison: Keta vs. High-Mercury Fish

To put Keta salmon's low mercury levels into perspective, consider the mercury concentrations of some commonly consumed high-mercury species.


Fish Species	Typical Mercury Concentration (PPM)	FDA/EPA Advice Category	Factors Influencing Level
Keta Salmon	Low (approx. 0.02)	Best Choice	Short lifespan, lower trophic level
Swordfish	High (approx. 0.995)	Choices to Avoid	Long lifespan, large predatory fish
Shark	High (approx. 0.979)	Choices to Avoid	Long lifespan, apex predator
Bigeye Tuna	High (approx. 0.689)	Choices to Avoid	Long lifespan, predatory fish
Canned Light Tuna	Low (approx. 0.13)	Best Choice	Shorter-lived species (skipjack)
Canned Albacore Tuna	Higher (approx. 0.35)	Good Choice	Larger tuna species

Preparing and Enjoying Keta Salmon Safely

Source your salmon wisely: Look for wild-caught Alaskan Keta salmon, which is known for its purity and sustainable harvesting practices. Certifications from organizations like the Marine Stewardship Council can also assure sustainability.
Follow FDA guidelines: The FDA and EPA recommend 2-3 servings of salmon per week for most adults, including pregnant and breastfeeding women.
Cook thoroughly: For safety, all fish should be cooked to an internal temperature of 145°F.
Vary your fish intake: While Keta is an excellent choice, rotating your seafood with other low-mercury options like shrimp, sardines, and pollock can provide a broader range of nutrients.
Balance is key: The omega-3s and other nutrients in fish provide significant health benefits that, for most people, far outweigh the small risk posed by trace amounts of mercury in low-level fish like salmon.

Conclusion

In conclusion, Keta salmon is not high in mercury. Its low position on the food chain and relatively short life cycle mean it accumulates very low levels of mercury, a fact confirmed by FDA data. Keta is considered a "Best Choice" for seafood consumption, even for vulnerable groups like pregnant women. Its nutritional profile, including high protein and beneficial omega-3 fatty acids, makes it a healthy addition to a balanced diet. By choosing responsibly sourced Keta salmon, you can enjoy a flavorful and healthy meal with confidence, without the undue concern of high mercury contamination.

Authoritative Link: U.S. Environmental Protection Agency Fish Consumption Guidelines

Frequently Asked Questions

Yes, Keta salmon is considered a low-mercury fish. It is a wild, Alaskan species with a shorter lifespan and lower food chain position than larger predatory fish, resulting in minimal mercury accumulation.

Yes, Keta salmon is safe to eat during pregnancy. The FDA and EPA include salmon in their 'Best Choices' category and recommend pregnant women consume 8 to 12 ounces of low-mercury fish per week.

Keta salmon has significantly lower mercury levels compared to high-mercury fish like shark, swordfish, and bigeye tuna. Its levels are comparable to other low-mercury options such as canned light tuna and shrimp.

Wild-caught Keta salmon generally exhibits very low levels of contaminants. While all salmon have traces, both wild and farmed salmon varieties are categorized as low-mercury choices by health authorities.

Keta salmon is a source of high-quality protein, omega-3 fatty acids (EPA and DHA), and important vitamins like B12, supporting heart, brain, and immune health.

Based on FDA guidelines, most adults can safely eat 2 to 3 servings of Keta salmon per week as part of a healthy diet, including pregnant and breastfeeding women.

No, cooking fish does not remove mercury. The mercury is bound to the fish's tissue and is not affected by heat. The best way to limit mercury intake is to choose low-mercury fish like Keta salmon.