Fish and levels of mercury

While fish is a healthy source of protein and the most abundant source of omega 3 fatty acids in our diet, it is important to select your fish carefully to minimize exposure to mercury and PCBs.

The fish with the least amount of mercury are:
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

Fish with moderate mercury are below.  It is advised to eat 6 or fewer servings per month of these fish:
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)

Fish with high levels of mercury should be eaten three or less times each month; they include:
Bluefish
Grouper*
Mackerel (Spanish, Gulf)
Sea Bass (Chilean)*
Tuna (Canned Albacore)
Tuna (Yellowfin)*

The fish with the highest amounts of mercury should not be consumed at all.  Sadly, you will see them served at restaurants so knowing this list is important.

Avoid eating:
Mackerel (King)
Marlin*
Orange Roughy*
Shark*
Swordfish*
Tilefish*
Tuna (Bigeye, Ahi)*

* Fish in Trouble! These fish are in danger of overfishing and/or are caught using environmentally destructive methods.

** Farmed Salmon may contain PCB’s, chemicals with serious long-term health effects.

Information on this page comes from the Monterey Bay Aquarium which also provides guidance about environmental factors and the NRDC (Natural Resource Defense Council.)  The NRDC information comes from the Food and Drug Administration, which tests fish for mercury, and the Environmental Protection Agency, which determines mercury levels that it considers safe for women of childbearing age.

The following mercury levels in the flesh of tested fish are used in the levels listed above:

  • Least mercury: Less than 0.09 parts per million
  • Moderate mercury: From 0.09 to 0.29 parts per million
  • High mercury: From 0.3 to 0.49 parts per million
  • Highest mercury: More than .5 parts per million