Mercury Levels in Fish

Mercury Levels in Fish

We know that fish can be very nutritious and are packed with great nutrients such as omega-3’s, the B vitamins and lean protein. But unfortunately, fish can also have some unhealthy contaminants. Mercury levels in fish is probably the greatest question of concern.

Mercury is a contaminant found in fish that can affect brain development and the nervous system. The FDA has released guidelines for children, women who are pregnant and women who are trying to become pregnant.  These guidelines state that no more than 12 oz of low mercury fish should be consumed weekly. “Highest” mercury fish should be avoided and “high” mercury fish should be kept to only three 6-oz servings per month.

Find a Nutritionist in your area

What does this mean for women who are pregnant but also trying to get some of their much needed nutrients from the critters of the sea?  It is all about moderation. Recent information released in the American Journal of Preventive Medicine says that no one should cut fish out of their diet altogether. Fish contains too many healthy nutrients that are essential for growth and development, especially in a pregnant mom and baby. There are 4 types of fish that should be on the list to avoid due to mercury levels. These include: shark, king mackerel, swordfish and tilefish.

For information regarding other types of fish, the Natural Resources Defense Council (NRDC) has released a list of fish and their mercury levels so that people can be informed on what they are consuming. If you want to get more detailed information about mercury levels and how much you personally are consuming, you can also use the mercury thermometer to calculate your totals.

Mercury Levels in Fish: Highest Mercury

AVOID Eating

  • Marlin
  • Orange roughy
  • Tilefish
  • Swordfish
  • Shark
  • Mackerel (king)
  • Tuna ( bigeye, Ahi)

High Mercury

Eat no more than three 6-oz servings per month

  • Sea Bass (Chilean)
  • Bluefish
  • Grouper
  • Mackeral ( Spanish, Gulf)
  • Tuna (canned, white albacore) See tuna chart below
  • Tuna ( Yellowfin)

Mercury Levels in Fish: Lower Mercury

Eat no more than six 6-oz servings per month

  • Bass ( Striped, Black)
  • Carp
  • Cod ( Alaskan)
  • Croaker ( White Pacific)
  • Halibut ( Pacific and Atlantic)
  • Jacksmelt ( Silverside)
  • Lobster
  • Mahi Mahi
  • Monkfish
  • Perch (freshwater)
  • Sablefish
  • Skate
  • Snapper
  • Sea Trout ( Weakfish)
  • Tuna (canned, chunk light)
  • Tuna (Skipjack)

Lowest Mercury

Enjoy two 6-oz servings per week

  • Anchovies
  • Butterfish
  • Catfish
  • Clam
  • Crab (Domestic)
  • Crawfish/crayfish
  • Croaker
  • Flounder
  • Haddock
  • Hake
  • Herring
  • Mackeral (N Atlantic, Chub)
  • Mullet
  • Oysters
  • Perch (ocean)
  • Plaice
  • Salmon ( Canned, Fresh)
  • Sardines
  • Scallops
  • Shad ( American)
  • Shrimp
  • Sole
  • Squid ( Calamari)
  • Tilapia
  • Trout (freshwater)
  • Whitefish
  • Whiting

Chart obtained from the Natural Resource Defense Council (NRDC); data obtained by the FDA and the EPA.

Tuna mercury levels can be different based on the type of tuna and where it was caught. The NRDC created the chart below as a guideline to how much tuna can be eaten by children, pregnant women or women wanting to conceive, based on their weight.

Weight in Pounds
White Albacore Chunk Light
1 can/10 wks 1 can/3 wks
1 can/6 wks 1 can/2 wks
1 can/5 weeks 1 can/11 days
1 can/4 weeks 1 can/9 days
1 can/3 weeks 1 can/7 days
1 can/3 weeks 1 can/6 days
1 can/2 weeks 1 can/ 6 days
1 can/2 weeks 1 can/5 days
1 can/2 weeks 1 can/5 days
1 can/12 days 1 can/4 days
1 can/11 days 1 can/4 days
1 can/10 days 1 can/4 days
1 can/10 days 1 can/3 days
150lbs +
1 can/9 days 1 can/3 days

Source: Food and Drug Administration test results for mercury levels in fish, and the Environmental Protection Agency’s determination of safe levels of mercury.


Last Updated: 01/2014

Compiled using information from the following sources:

U.S. Food and Drug Administration,

Natural Resources Defense Council,

American College of Preventive Medicine,