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Facts on Fish and Seafood

Benefits of eating fish and shellfish

Fish and shellfish are good sources of protein, vitamin D and the best source of omega-3 fats. Eating fish and shellfish is important for heart health, children’s growth and for a healthy pregnancy.

Everyone over the age of two (including pregnant women) should eat at least 150 grams (5 ounces) of fish and shellfish that are low in mercury each week. The benefits of eating fish far out weigh the risks.

Low mercury fish and shellfish to eat weekly

  • ‘Light’ canned Tuna (specifically labelled ‘skipjack’, ‘yellowfin’ or ‘tongol’).
  • Salmon
  • Cod, Haddock, Halibut
  • Sole and Tilapia
  • Rainbow Trout
  • Char
  • Herring
  • Atlantic mackerel
  • Pollock (Boston bluefish)
  • Blue crab, Scallop, Shrimp, Clam, Mussel, Oyster
  • Lake whitefish
  • Anchovy, Sardines
  • Perch, Bass

Which fish should be eaten less often?

Mercury can build up in some fish. Eating these types of fish too often or in large amounts can lead to health risk. The risk is higher in women who are pregnant, may become pregnant and in young children. Big predatory fish contain the most mercury. Shark, swordfish, king mackerel, tilefish, pickerel, marlin, orange roughy, escolar, and fresh or frozen tuna steaks are examples of high mercury fish.

How often can I eat these higher mercury fish?

  • General Population – no more than 150 grams (5 ounces) per week
  • Women who are or may become pregnant or are breastfeeding – no more than 150 grams (5 ounces) per month
  • Children 1-4 years old – no more than 75 grams (2 ½ ounces) per month
  • Children 5 -11 years old – no more than 125 grams (about 4 ounces) per month

What about canned tuna?

As long as you eat the canned light tuna variety (skipjack, yellowfin, and tangol), you don’t need to worry. These types of tuna are safe and low in mercury.

Canned albacore (white) tuna can be higher in mercury. Children 1 to 11 years old and women who are or may become pregnant or are breastfeeding should limit how much canned albacore tuna they eat.

Here are the guidelines:

  • Women who are or may become pregnant or are breastfeeding – no more than 300 grams (10 ounces) per week
  • Children 1 – 4 years old – no more than 75 grams (2 ½ ounces) per week
  • Children 5 – 11 years old – no more than 150 grams (5 ounces) per week

What about fish that I catch?

Some fish caught in lakes and rivers may not be safe to eat. Check the Guide to Eating Ontario Sport Fish at or phone 1-800-820-2716 to get a free copy.

Tips for eating fish

  • Use lower fat cooking methods like grilling, poaching, broiling or baking fish. Avoid eating deep fried or battered fish often.
  • Flavour fish using lemon, herbs like dill or spices like curry.
  • If you like mild tasting fish, eat canned fish cold on salad or as a sandwich filling.

Special considerations for pregnant women and young children

  • Make sure fish and seafood is well cooked. Avoid raw fish because it might have harmful bacteria on it.
  • Avoid taking cod liver oil supplements. They might contain too much vitamin A.
  • Make sure all bones are removed from fish when serving to babies and young children.

Where Can I Find More Information?

  • Haldimand-Norfolk Health Unit
  • Eat Right Ontario
  • Speak with a Registered Dietitian for free by calling

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