The Short Answer
The lowest-mercury fish are small, short-lived species like sardines, anchovies, salmon, and shrimp. These fish average less than 0.05 parts per million (ppm) of mercury, making them exceptionally safe for everyone to eat 2-3 times per week.
You do not need to avoid seafood entirely to dodge mercury. While the FDA's "Action Limit" for taking fish off the market is 1.0 ppm, sticking to the cleanest species keeps your exposure radically lower. If you want to know what to explicitly avoid, check out What Fish Has The Most Mercury.
Why This Matters
Nearly all fish contain trace amounts of methylmercury, but mercury bioaccumulates as it moves up the food chain. Small fish absorb tiny amounts of the heavy metal, medium fish eat thousands of those small fish, and large predators eat the medium fish.
By the time a swordfish or shark reaches your plate, it can contain 100 times more mercury than a sardine. This neurotoxin is especially dangerous for pregnant women and young children because it easily crosses the placenta and interferes with early brain and nervous system development.
The FDA categorizes fish into "Best Choices," "Good Choices," and "Choices to Avoid." Fish on the FDA "Best Choices" list average less than 0.15 ppm of mercury, making them the safest options for regular meals. You can find detailed breakdowns of these rankings in our guide on What Seafood Has The Lowest Mercury.
What to Look For
Green Flags:
- The "SMASH" Fish â Salmon, Mackerel (Atlantic/Pacific only), Anchovies, Sardines, and Herring are nutritional powerhouses with incredibly low mercury levels. Are Canned Sardines And Anchovies Healthy
- Skipjack or "Chunk Light" Tuna â Skipjack tuna are smaller and younger when caught, meaning they accumulate roughly one-third the mercury of larger albacore tuna. Is Albacore Or Chunk Light Tuna Lower In Mercury
- Third-Party Testing â Premium brands like Safe Catch and Wild Planet test every batch to guarantee mercury levels fall well below FDA limits. What Is The Safest Canned Tuna Brand
Red Flags:
- Large Predator Fish â Swordfish, shark, king mackerel, and tilefish routinely test near or above the FDA's 1.0 ppm danger limit.
- White Albacore Tuna â Because albacore are larger and live longer, they consistently test around 0.35 ppmâtoo high for regular consumption by pregnant women. Is Canned Tuna Safe To Eat Weekly
- Vague Sourcing â If a can just says "tuna" without specifying the exact species or catch method, it's likely a mix of larger, higher-mercury fish.
The Best Options
When shopping for low-mercury fish, look for small species and brands with transparent testing protocols.
| Brand | Product | Verdict | Why |
|---|---|---|---|
| Safe Catch | Elite Wild Tuna (Skipjack) | â | Tests every single fish to a strict 0.1 ppm limit. |
| Wild Planet | Wild Sockeye Salmon | â | Naturally low in mercury, averaging just 0.013 ppm. |
| Season | Wild Caught Sardines | â | Tiny, short-lived fish that accumulate almost zero mercury. |
| StarKist | Chunk Light Tuna | â ïž | Lower mercury than albacore, but lacks strict batch testing. |
| Bumble Bee | Solid White Albacore | đ« | Albacore is a larger species that frequently tests too high for vulnerable groups. |
The Bottom Line
1. Eat down the food chain. Small fish like sardines, anchovies, and shrimp are the absolute safest choices for frequent consumption.
2. Choose skipjack over albacore. If you love tuna, "chunk light" or skipjack has significantly less mercury than white albacore.
3. Rely on tested brands. If you are pregnant or feeding kids, spend the extra dollar on premium brands like Safe Catch that test every single fish.
FAQ
What fish has absolutely zero mercury?
No ocean fish is 100% free of mercury. However, short-lived fish like wild salmon, sardines, and scallops have levels so low (often around 0.01 to 0.02 ppm) that they are effectively negligible for human health.
Is farmed salmon lower in mercury than wild salmon?
Farmed salmon often tests slightly lower in mercury because of their controlled diet. However, farmed salmon comes with other serious concerns like antibiotic use, PCBs, and artificial dyes. Read our deep dive on Is Farmed Salmon Safe To Eat to weigh the pros and cons.
Can I eat canned tuna every day?
It depends entirely on the type of tuna. You should not eat albacore every day due to its higher mercury content, but rigorously tested skipjack brands can be eaten much more frequently. See Is Canned Tuna Safe To Eat Weekly for the exact math.
Are shrimp and oysters safe from mercury?
Yes, shellfish like shrimp, oysters, and scallops are among the lowest-mercury seafood available. However, they can harbor other issues like heavy metal bioaccumulation (in oysters) or questionable farming practices (in imported shrimp). Check out Are Oysters Safe and Is Shrimp Safe To Eat before you buy.