What Seafood Has the Lowest Mercury?

The Short Answer

Scallops, clams, and shrimp have the absolute lowest mercury levels of all commercial seafood, averaging under 0.01 parts per million (ppm). Close behind are wild salmon, sardines, and oysters, all testing safely below 0.03 ppm.

The FDA classifies these as "Best Choices," meaning anyone can safely eat two to three servings per week. As a general rule, the smaller the seafood and the lower it is on the food chain, the cleaner it will be.

Why This Matters

Mercury is a potent neurotoxin that accumulates in the human body over time. It is especially dangerous to pregnant women and young children because it can permanently impair fetal brain development.

Most ocean mercury comes from industrial pollution, specifically coal-fired power plants. This pollution settles into the water, converts into highly toxic methylmercury, and gets absorbed by aquatic life.

The real danger lies in a process called biomagnification. Small fish absorb tiny amounts of mercury, but when massive predators eat thousands of those small fish over a decades-long lifespan, the heavy metals concentrate.

This is why a swordfish carries over 100 times the mercury of a scallop. Eating the wrong types of seafood can completely erase the nutritional benefits of the omega-3s. What Fish Has The Most Mercury

What's Actually In Low-Mercury Seafood

• Scallops (0.003 ppm) — The undisputed champion of clean seafood. Because they are stationary filter feeders with short lifespans, they accumulate practically zero mercury.
• Shrimp & Clams (0.009 ppm) — Tied for second place among the cleanest options. However, you still need to verify the sourcing of imported shrimp for antibiotic use. Is Shrimp Safe To Eat
• Oysters (0.012 ppm) — A low-toxin nutritional powerhouse. They are loaded with essential zinc and vitamin B12, with barely a trace of heavy metals. Are Oysters Safe
• Canned Salmon (0.014 ppm) — One of the safest ways to get omega-3s. Often made from wild-caught pink salmon, it ranks exceptionally low for contamination. Is Canned Salmon Healthy
• Sardines & Anchovies (0.013 - 0.017 ppm) — The ultimate clean protein. These tiny forage fish eat plankton instead of other fish, keeping their toxic load incredibly low. Are Canned Sardines And Anchovies Healthy
• Fresh Salmon (0.022 ppm) — Clean despite their larger size. Salmon have relatively short lifespans and a diet low on the food chain, keeping them safe for frequent consumption. Is Farmed Salmon Safe To Eat

What to Look For

Green Flags:

• Short lifespans — Fish that live only a few years don't have time to accumulate high levels of heavy metals.
• Plankton eaters — Species that eat plants or microscopic organisms are always cleaner than fish that eat other fish.
• Filter feeders — Bivalves like oysters, clams, and scallops naturally filter water and carry the lowest heavy metal loads.

Red Flags:

• Top predators — Sharks, swordfish, and marlin sit at the top of the food chain and are swimming mercury traps.
• Long lifespans — High-mercury fish like Orange Roughy can live for decades, accumulating toxins every single day.
• "Big" Tuna — Bigeye and bluefin tuna are massive predators and contain dangerously high mercury levels compared to smaller species. What Is The Safest Canned Tuna Brand

The Best Options

Choosing the right seafood is entirely about picking the right species. Here is how common choices rank for mercury toxicity, based on FDA testing data.

The Bottom Line

1. Eat smaller fish. Sardines, anchovies, and shellfish are your safest bets for frequent, low-toxin consumption.

2. Limit canned tuna. Even "safer" chunk light tuna should be limited to once a week for pregnant women and children. Is Canned Tuna Safe To Eat Weekly

3. Avoid the big predators. Never eat shark, swordfish, king mackerel, or tilefish—the toxic load simply isn't worth it.

FAQ

Is chunk light tuna or albacore lower in mercury?

Chunk light tuna is significantly cleaner than albacore. Albacore tuna are larger, older fish, meaning they accumulate about three times as much mercury (0.35 ppm) as the skipjack tuna (0.12 ppm) typically used for chunk light. Is Albacore Or Chunk Light Tuna Lower In Mercury

Should pregnant women stop eating fish entirely?

No, the omega-3s in fish are crucial for fetal brain development. The FDA and pediatricians recommend 8-12 ounces per week of "Best Choice" low-mercury fish. Completely avoiding seafood deprives both mother and baby of essential nutrients.

Does cooking fish reduce its mercury content?

Cooking does nothing to remove mercury. Methylmercury binds tightly to the proteins in the fish's muscle tissue. Whether you bake, fry, or eat it raw, the mercury level remains exactly the same.