Amberjack contains moderate levels of mercury, placing it in the middle range among popular saltwater fish. Based on testing from the University of West Florida, greater amberjack samples averaged roughly 0.25 mg/kg of mercury, with individual fish ranging from 0.11 to 0.45 mg/kg. Most samples fell below the EPA screening value of 0.46 mg/kg, but larger fish came close to or exceeded that threshold.
That puts amberjack above low-mercury options like salmon, tilapia, and shrimp, but well below high-mercury fish like swordfish, king mackerel, and shark, which routinely exceed 0.7 mg/kg. In practical terms, amberjack is a fish you can enjoy occasionally without major concern, but not one to eat multiple times a week.
Why Amberjack Accumulates Mercury
Amberjack are large, long-lived predators that sit high on the ocean food chain. Mercury builds up through a process called bioaccumulation: small organisms absorb trace amounts of mercury from the water, mid-sized fish eat those organisms, and top predators like amberjack concentrate the mercury from everything below them. The bigger and older the fish, the more mercury it has stored in its tissue.
This pattern showed up clearly in testing. Among the nine amberjack sampled off the Florida coast, mercury concentrations tracked with body size. The only fish that exceeded the EPA screening value was the largest specimen. Younger, smaller amberjack carried significantly less mercury, with one lesser amberjack testing as low as 0.02 mg/kg.
Greater vs. Lesser Amberjack
Greater amberjack, the species most commonly caught and sold, is the larger of the two and carries more mercury as a result. The seven greater amberjack tested ranged from 0.11 to 0.45 mg/kg. Lesser amberjack, a smaller and less commonly targeted species, tested at just 0.02 and 0.10 mg/kg. If you have the option, lesser amberjack is the lower-mercury choice, though it’s far less common at fish markets and restaurants.
How Often You Can Safely Eat It
For most adults, eating amberjack once a week is reasonable. At an average mercury concentration around 0.25 mg/kg, a standard 6-ounce serving delivers a mercury dose that falls within safe weekly limits for the average person. Eating it two or three times a week would push you closer to thresholds where mercury exposure becomes a concern over time.
Pregnant women and young children face stricter guidelines. The FDA groups fish into “best choices” (two to three servings per week), “good choices” (one serving per week), and fish to avoid entirely. Amberjack’s mercury levels place it in the “good choices” category at best, meaning pregnant women should limit it to one serving per week and prioritize lower-mercury fish like salmon, sardines, or pollock for their regular seafood intake.
Ciguatera: The Other Safety Concern
Mercury isn’t the only risk with amberjack. This species is one of the most common carriers of ciguatera, a type of food poisoning caused by a toxin that originates in algae growing on coral reefs. Small reef fish eat the algae, and predators like amberjack accumulate the toxin as they feed up the food chain, similar to the way they accumulate mercury.
What makes ciguatera tricky is that contaminated fish looks, smells, and tastes completely normal. You can’t cook, freeze, or wash the toxin away. The highest concentrations build up in the head, intestines, liver, and eggs of affected fish, so eating only the fillet reduces your exposure somewhat. Ciguatera causes neurological symptoms like tingling, temperature reversal (cold things feel hot and vice versa), nausea, and muscle pain, sometimes lasting weeks or months.
The risk is highest with amberjack caught near tropical and subtropical coral reefs, particularly in the Caribbean, South Florida, Hawaii, and the Pacific Islands. Fish caught in cooler, deeper waters farther from reefs carry lower risk. There’s no reliable way to test fish at home, so if you catch your own amberjack in reef-heavy areas, keeping smaller fish and avoiding the organs is the best precaution available.
Nutritional Benefits of Amberjack
Despite the mercury and ciguatera concerns, amberjack is a nutritionally dense fish. A 100-gram serving (about 3.5 ounces) provides 23 grams of protein and just 146 calories, with 5 grams of fat. It’s also an excellent source of selenium, delivering 36.5 micrograms per serving, which is roughly two-thirds of the daily recommended intake. Selenium plays a role in thyroid function and may help counteract some of mercury’s harmful effects in the body, since it binds to mercury and reduces its ability to damage cells.
Amberjack is zero carb and relatively low in sodium at 39 mg per serving, making it a solid choice for people watching their blood sugar or salt intake. Its fat content is moderate compared to fatty fish like salmon or mackerel, so it provides some omega-3 fatty acids but isn’t the richest source. For maximum omega-3 benefit with minimal mercury, fish like sardines, anchovies, and wild salmon remain better everyday options.