As you choose your fish, consider these recommendations:
• Eat lower on the food chain: Smaller fish are more plentiful and contain less mercury.
• Know where the fish is from: Regional differences in the health of different species make choosing a sustainable fish more of a challenge. The Monterey Bay Aquiarium's guide to choices is a good one for reference.
• Buy American: The U.S. variety of a particular fish often is a result of stricter fishing and farming standards.
• Buy wild when possible: The environmental impact of fish farming is complicated.
• Know how it's caught: Some methods of harvesting fish are more sustainable than others.
• Buy from trusted retailers.
Natural Resources Defense Council