Food Safety: Mercury in Fish

HealthLinkBC File Number: 
68m
Last Updated: 
January 2016

Fish provides many nutrients such as protein, selenium, vitamin D, magnesium, iodine and iron. Fish is also low in saturated fat and provides healthy omega-3 fats, which are good for your brain and heart. Omega-3 fats are important for brain and eye development in babies and children.

Eating Well with Canada's Food Guide (CFG) recommends that adults and children who are 2 years of age or older, eat at least 2 servings of fish each week. One Canada’s Food Guide serving of fish is equal to:

  • 75 grams;
  • 2 ½ ounces;
  • 125 mL; or
  • ½ cup.

While there are health benefits of eating fish regularly, it is important to know that mercury is present in various levels in different types of fish. In large amounts, mercury can be harmful to your health.

Why is there mercury in fish?

There are natural sources of mercury found in the environment, but human activity such as mining, burning of waste and hydroelectric dams have increased the amount of mercury found in soil and water. Fish absorb this mercury, which your body then absorbs when you eat the fish.

Larger fish that eat smaller fish usually have the highest mercury levels. Cleaning, preparing or cooking fish will not remove or reduce any amount of mercury.

How is mercury harmful to my health?

Mercury may have harmful effects on the nervous system, including the brain. The brain is most sensitive when it is growing and developing. Pregnant and breastfeeding women, babies and children are the most at risk from eating fish with higher levels of mercury. Health Canada recommends you eat fish that is low in mercury and limit intake of fish that is higher in mercury.

Which fish have higher levels of mercury?

Fish with higher levels of mercury include:

  • tuna* (fresh or frozen);
  • shark;
  • marlin:
  • swordfish;
  • escolar; and
  • orange roughy.

*Note: Canadian North Pacific albacore tuna (fresh, frozen and canned) has been well tested for mercury by the Canadian Food Inspection Agency and is considered safe to eat. The mercury level in these fish is lower than other albacore tunas. To find Canadian albacore tuna, look for the statement “Product of Canada” on the label.

How much fish is safe to eat?

Health Canada provides specific advice for different groups of people. The following tables show the recommended serving limits for you and your family.

Tuna, shark, marlin, swordfish, escolar, and orange roughy:

Age Serving Limit
Children 6 to 12 months 40 grams (1 ¼ ounces) per month
(approximately ½ CFG serving a month)
Children 1 to 4 years 75 grams (2 ½ ounces) per month
(1 CFG serving a month)
Children 5 to 11 years 125 grams (4 ounces) per month
(less than 2 CFG servings a month)
Women of childbearing age, including pregnant and breastfeeding women 150 grams (5 ounces) per month
(2 CFG servings a month)
Men 12 years and older, and women after childbearing years 150 grams (5 ounces) per week
(2 CFG servings per week)

Canned albacore (white) tuna is also higher in mercury, but not as high in mercury as those fish listed above. However, Health Canada recommends that you limit the amount of canned albacore tuna that you eat.

Canned albacore tuna*:

Age Serving Limit
Children 6 to 12 months 40 grams (1 ¼ ounces) per week
(approximately ½ CFG serving a week)
Children 1 to 4 years 75 grams (2 ½ ounces) per week
(1 CFG serving a week)
Children 5 to 11 years 150 grams (5 ounces) per week
(2 CFG servings a week)
Women of childbearing age, including pregnant and breastfeeding women 300 grams (10 ounces) per week
(4 CFG servings a week)
Men 12 years and older, and women after childbearing years No limit

*Note: Canned albacore tuna (labelled with ‘Product of Canada’) has no serving limits

Can I eat other types of fish not on the list?

Yes. There are no recommended mercury limits for eating fish sold in Canada. There is no limit placed on the amount of canned light tuna including the skipjack, yellowfin, and tongol species.

Can I eat fish caught by family and friends?

The risk of mercury in lakes and streams in British Columbia is normally low. However, testing is done when the risk of contamination is higher, such as in areas where there are reservoirs or natural mercury deposits.

As of 2015, only 3 lakes in B.C. have mercury advisories. These advisories are for lake trout and bull trout in Jack of Clubs, Pinchi and Williston Lakes.

For More Information

For more information, visit the following websites:

For information on freshwater fishing regulations and alerts, visit Ministry of Forests, Lands and Natural Resource Operations www.env.gov.bc.ca/fw/fish/regulations or call 250-387-9711 or toll free 1-866-387-9771.

For more nutrition information, call 8-1-1 to speak with a registered dietitian.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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