Do Lobsters Have High Mercury? Separating Myth from Fact

November 3, 2025 •

3 min read

According to the U.S. Food and Drug Administration (FDA), the mean mercury level in American lobster is relatively low, placing it in the "Best Choices" category for consumption. This fact directly addresses the common misconception that do lobsters have high mercury, confirming they are a safe, low-mercury seafood choice when consumed in moderation.

Quick Summary

Lobster contains low to moderate levels of mercury, significantly less than larger predatory fish. Health risks are minimal for most people with moderate consumption, though pregnant women and young children should monitor intake.

Key Points

Low Mercury Content: American lobster has a low mean mercury level (approx. 0.107 ppm) and is categorized as a "Best Choice" for consumption by the FDA.
Moderate Consumption Safe: For the general population, moderate consumption of lobster poses minimal risk of mercury exposure.
High-Mercury Foods Are Different: The highest mercury levels are found in large, predatory fish like shark and swordfish, not shellfish like lobster.
Vary Your Diet: The safest approach is to eat a variety of low-mercury seafood rather than relying on one type.
Beware the Tomalley: The tomalley (digestive gland) can contain higher concentrations of mercury and should be limited or avoided by sensitive groups, such as pregnant women.
Risk vs. Benefit: The nutritional benefits of eating seafood, including omega-3s and lean protein, often outweigh the minimal mercury risk associated with low-mercury options like lobster.

Lobster's Mercury Profile: Moderation is Key

Lobsters are a sought-after culinary delight, but with growing awareness of mercury in seafood, many wonder about the safety of their favorite shellfish. The good news is that lobsters are not considered high in mercury. In fact, their levels are significantly lower than those found in large, predatory fish. This is due to their position lower on the marine food chain and their shorter lifespan compared to species like shark or swordfish.

Why Mercury Levels Vary in Seafood

The presence of methylmercury in fish and shellfish is the result of a process called biomagnification. Mercury from industrial and natural sources enters the water, where bacteria convert it into the organic, more toxic form of methylmercury. This compound is then absorbed by small organisms, which are, in turn, consumed by larger marine life. As it moves up the food chain, the concentration of mercury increases in the body tissue of each successive predator. This explains why larger, longer-lived, predatory fish accumulate higher levels of mercury than smaller seafood species.

A Closer Look at Lobster Species and Mercury

While overall mercury levels in lobster are low, some variations exist based on species and location. For example, some studies have found that American (or Northern) lobsters contain a mean mercury concentration of around 0.107 ppm, which is well within safe consumption limits. Other studies on spiny lobster found similar low mean levels. In certain localized areas, however, environmental contamination can lead to elevated levels, as seen in a former industrial site in Maine where a lobster harvest area was temporarily closed.

Where is Mercury Found in a Lobster?

Tail Meat: This is the primary edible portion of the lobster. Studies have shown that mercury concentrations are generally highest here, though still within safe limits for consumption.
Tomalley (Hepatopancreas): The green-colored digestive gland in the lobster's body, often considered a delicacy, can contain higher concentrations of mercury than the tail meat in some circumstances. For this reason, some health advisories recommend limiting or avoiding consumption of tomalley, particularly for sensitive groups.
Claw Meat: Mercury levels in the claw meat are typically similar to or slightly lower than those in the tail.

How to Safely Enjoy Lobster

For the vast majority of people, eating lobster is a safe and healthy practice. The key is balance and moderation within your overall diet. The FDA categorizes American lobster as a "Best Choice" for consumption, meaning it's a low-mercury option. Here are some tips for incorporating it into your diet safely:

Vary Your Seafood: Don't rely solely on one type of seafood. By rotating between low-mercury choices, you can diversify your nutrient intake while minimizing risk.
Pay Attention to Advisories: Be mindful of local or regional advisories that might exist due to specific contamination events.
Limit High-Mercury Species: Reduce consumption of known high-mercury fish such as swordfish, king mackerel, and shark.
Be Mindful of Tomalley: If you are in a sensitive group, such as a pregnant or nursing woman or a young child, consider limiting or avoiding the tomalley, the lobster's green digestive organ.

Comparison of Seafood Mercury Levels (Mean in ppm)


Seafood Species	Average Mercury Level (ppm)	Mercury Risk Category	Notes
American Lobster	0.107	Low	"Best Choice" according to the FDA.
Shrimp	0.009	Very Low	One of the lowest mercury options available.
Salmon	0.022 (fresh/frozen)	Very Low	A great source of omega-3s with minimal mercury.
Canned Light Tuna	0.126	Low-Moderate	Still a good choice, but slightly higher than lobster.
Canned Albacore Tuna	0.350	Moderate-High	Higher mercury than light tuna, requires more moderation.
Swordfish	0.995	High	One of the highest mercury species due to its size.
Shark	0.979	High	Large apex predator with very high mercury levels.

Conclusion

In conclusion, the concern over whether do lobsters have high mercury levels is largely misplaced. While no seafood is entirely mercury-free, lobster's average concentration is low, making it a safe and healthy choice for most individuals. The risk is primarily associated with larger, long-lived predatory fish that sit at the top of the food chain. For lobster, moderate consumption of the muscle meat presents little to no risk. For sensitive populations, being cautious with the tomalley is a prudent step, but should not overshadow the overall safety of this nutritious delicacy. Enjoying a varied diet of low-mercury seafood, including lobster, provides valuable nutrients without the significant heavy metal exposure concerns associated with other fish.

Visit the FDA's website for official seafood consumption advice

Frequently Asked Questions

Yes, it is generally safe for pregnant women to eat lobster in moderation. The FDA places American lobster in its 'Best Choices' category for low mercury seafood. Pregnant women should still follow recommended consumption amounts and consider avoiding the tomalley, the green digestive gland where mercury can concentrate.

Lobster has significantly lower mercury levels than many types of tuna, especially albacore, which is considered a moderate-to-high mercury fish. Lobster's mercury content is comparable to or slightly higher than very low-mercury fish like salmon, and much lower than high-mercury predators like swordfish.

Mercury can be found in all parts of the lobster, but concentrations are typically highest in the tail meat and potentially higher still in the tomalley (the green digestive gland). The claw meat usually has similar or slightly lower levels than the tail meat.

For most people, eating lobster several times a month as part of a varied diet is considered safe. The key is to balance your seafood intake with other low-mercury options and be aware of your total consumption of different types of seafood.

Mercury levels depend on the marine animal's position on the food chain and its lifespan. Shellfish like shrimp and scallops, which are filter-feeders, have very low levels. Lobster is also lower on the food chain than large predatory fish, and its lifespan is shorter than the largest fish species, resulting in lower mercury accumulation.

No, if you eat lobster only occasionally, there is no significant cause for concern regarding mercury levels. The health risks from mercury are linked to long-term, high-level exposure, which is not associated with moderate consumption of low-mercury seafood.

Cooking does not remove mercury from seafood. While boiling may affect how mercury is measured in some studies, it does not reduce the actual mercury concentration. Mercury is bound to the meat and remains present regardless of cooking method.