OTTAWA - Following years of monitoring mercury levels in fish, Health Canada says it is advising certain groups to limit their consumption of canned albacore tuna.

The advisory applies to women who are pregnant or may become pregnant, breastfeeding mothers and children.

Mercury levels in most canned tuna are well below Health Canada's accepted standards, the advisory states.

"Levels in canned albacore tuna are higher than levels in other types of canned tuna, but are generally below the standard as well,'' Health Canada says.

As a precaution, it says women who are or who may become pregnant, and nursing mothers, can eat up to four Food Guide servings of canned albacore tuna per week. One serving is 75 grams, or half a cup.

Children between one and four can eat up to one serving a week, and kids between five and 11 can eat up to two servings a week.

Canned albacore tuna is not the same as canned light tuna, which contains other species of tuna such as skipjack, yellowfin and tongol, which are relatively low in mercury. There is no new consumption advice related to canned light tuna.

Health Canada calls its advisory an update.

"Canadians can rest assured that there is no reason to stop eating canned tuna,'' it says.