Light tuna is the safer choice for pregnant women.

Yes, mercury varies a lot by species, and the guidelines are pretty straightforward: smaller tuna have less mercury, larger ones have more. Skipjack (what you usually get in canned “light” tuna) is your safest bet. Albacore (“white” tuna) is bigger and older, so it has about three times more mercury. Bigeye and yellowfin—often in sushi or steaks—are the worst offenders.

The FDA says pregnant women and kids can eat 2–3 servings a week of light tuna. For albacore, they recommend no more than one serving per week. And honestly? I’d avoid bigeye or yellowfin altogether during pregnancy. The general population doesn’t need to worry much, but if you’re pregnant or feeding kids, stick with skipjack and don’t go crazy.

This isn’t the place to take chances.