This month's Consumer Reports has an article about the safety issues in tuna along with recommendations on just how much or what kind of tuna is best to eat.
Albacore white tuna may seem the best but it actually has higher levels of mercury than the regular canned light tuna. Mercury is especially dangerous for pregnant women and young children. This also applies to yellow fin and other fish used in sushi.
Actually, it looks as though mercury is high in lots of fish.
Also the latest issue has a rather icky story on shrimp and the strong possibility of bacteria that can be found on them. Seems a huge amount of our shrimp comes from overseas, Bangladesh, India, Indonesia, Ecuador, Vietnam, Thailand and Argentina, all bred in ponds. Some of the contamination found on shrimp was, vibrio, staphylococcus aureus, E. Coli, listeria, and salmonella. The percent of any of these ranged from 83 percent to 20 percent. The US bred shrimp had the least, while Bangladesh had the most.
Not a fun story at all. Consumer Reports does not feature their stories on their website, but requires a subscription. The magazine is on newsstands. I got mine at Schnucks.