Fish And Mercury - What You Need to Know

Photo of Daisy Whitbread Written by Daisy Whitbread
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Fish And Mercury - What You Need to Know

Fish provides a heart-healthy source of protein and contain a host of nutrients including omega-3 fatty acids and vitamin B12. However, the issue of mercury poisoning looms over anyone considering making fish a staple part of their diet. Do you know the facts?

What are the risks with Mercury?
According to the U.S. EPA (Environmental Protection Agency): For most people, the risk from eating contaminated fish and shellfish is not a health concern. (1) While no exact risks are known, consumers are advised to be cautious, moderate consumption, and adjust preferences for fish with lower mercury values. Ideally, no one wants to eat mercury because it is a neurotoxin thought to impair brain functioning and development. The amount of mercury anyone can process depends on their weight. This is why the Department of Health warns pregnant women and children not to consume high mercury fish.

What kinds of fish have high amounts of Mercury?
Mercury exists in our waters and subsequently in some of the fish we eat. The concentration of mercury in local-waters varies, and therefore so does, the content in any given fish. Due to bio-amplification, fish at the top of the predator chain are far more likely to contain high amounts of mercury than smaller fish. (2)

So How Do You Know What to Buy?
The following lists give you a shopping guide for what fish to buy. Feel free to print them out. The EPA also publishes these figures in a printable wallet card available here.
Listing of Fish Low in Mercury Anchovies Butterfish Catfish Clam Crab (Domestic) Crawfish Crayfish Croaker (Atlantic) Flounder Haddock (Atlantic) Hake Herring Mackerel (N.Atlantic, Chub) Mullet Oyster Perch (Ocean) Plaice Pollock Salmon (Canned) Salmon (Fresh)Sardine Scallop Shad (American) Shrimp Sole (Pacific) Squid (Calamari) Tilapia Trout (Freshwater) Whitefish Whiting
Listing of Fish Moderate in Mercury Bass (Striped, Black) Carp Cod (Alaskan) Croaker (White Pacific) Halibut (Atlantic) Halibut (Pacific) Jacksmelt(Silverside) Lobster Mahi Mahi Monkfish Perch (Freshwater) Sablefish Skate Snapper Tuna (Canned chunk light) Tuna (Skipjack) Weakfish (Sea Trout)
Listing of Fish High in Mercury Bluefish Grouper Mackerel(Spanish, Gulf) Sea Bass (Chilean) Tuna(Canned Albacore) Tuna (Yellowfin) Bluefish Grouper Mackerel(Spanish, Gulf) Sea Bass (Chilean) Tuna (Canned Albacore) Tuna (Yellowfin)

What about canned fish?
The amount of mercury in fish is not affected by canning. In general, avoid high sodium or oil-packed canned fish.

Are fish in my local lakes, ponds, and streams safe?
Mercury exists in the ocean and in our local waters. You can use the EPA's national database to find mercury levels for particular lakes and streams in your area.

Data Sources and References

  1. The U.S. EPA: Should I Be Concerned About Eating Fish and Shellfish?
  2. Trophic Structure and Mercury Biomagnification in Tropical Fish Assemblages, Itenez River, Bolivia
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