Wellness Food 10 Fish You Should Avoid (and Why) Species to steer clear of, due to higher-than-average levels of mercury, harmful chemicals, and other health no-nos. By Karen Cicero Published on June 28, 2013 Share Tweet Pin Email Fish is among the healthiest foods you can eat. It's filled with good fats and protein, and has been shown to fight heart disease, boost brain health, and more.Here's the catch: You can easily cancel out these health benefits if the fish you eat is contaminated with mercury, antibiotics, or harmful chemicals like PCBs. Use this quick-and-dirty guide to help you steer clear of suspect species that carry higher-than-average health risks. 01 of 10 Imported catfish Getty Images Why you should avoid it: Imported catfish may contain antibiotics banned in food in the United States. 02 of 10 Farmed eel Getty Images Why you should avoid it: Farmed eel is potentially high in PCBs and mercury. 03 of 10 King mackerel Getty Images Why you should avoid it: King mackerel tends to contain high levels of mercury. 04 of 10 Orange roughy Getty Images Why you should avoid it: Orange roughy is high in mercury—and also overfished. 05 of 10 Chilean sea bass Getty Images Why you should avoid it: Like orange roughy, Chilean sea bass are both overfished and may contain mercury. 06 of 10 Shark Getty Images Why you should avoid it: Shark meat contains high levels of mercury. 07 of 10 Imported shrimp Getty Images Why you should avoid it: Imported shrimp may contain antibiotics and chemical residue. 08 of 10 Swordfish Getty Images Why you should avoid it: Like many larger species, swordfish is high in mercury. 09 of 10 Tilefish Getty Images Why you should avoid it: Tilefish are high in mercury. 10 of 10 Bluefin Tuna Getty Images Why you should avoid it: Many varieties of tuna contain mercury, but the levels may be higher in bluefin tuna, which are also overfished. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit