There was a discussion within a thread on shark fishing recently about mercury content in Alaska's fish. For those of you unfamiliar with the topic, mercury tends to accumulate in the flesh of top-water predatory fish and larger fish with long life spans. Mercury can cause serious birth defects and should be avoided by pregnant women, women who may become pregnant, or young children.
Looking at this list from a state website, women and young children should obviously stay away from salmon shark and spiny dogfish. Additionally, my wife and I have decided that burbot, yelloweye rockfish, large halibut, and lingcod have too much mercury to mess with. Thankfully, salmon and small halibut have very low levels of mercury, and those make up the majority of our fish diet.