Here's why some fish are good for you, some not so good, and what you can do to enjoy safe and healthy seafood at home.

Eating fish once or twice a week can do wonderful things for your heart and your health—if you choose the right types and prepare them in healthful ways. Most standard food safety advice applies especially to fish. Seafood is highly perishable and must be kept very cold from the time it leaves the water until it winds up on your plate. That's why fresh seafood is always sold "on ice" and why it needs to be refrigerated as soon as you get it home.

Choose the healthiest varieties of fish and practice standard food safety measures when preparing seafood at home, such as working with clean hands on a clean surface, and cooking fish thoroughly.

But, fish safety starts with safe fish.

Three main types of contaminants can be found in the fish we eat, according to the Environmental Defense Fund:

  1. Heavy metals, such as mercury and lead
  2. Industrial chemicals such as PCBS
  3. Pesticides  can all end up in fish when rain and unsafe industrial practices wash contaminated water from the land into lakes, reservoirs, and estuaries. Some contaminants collect in the fatty parts of fish while others collect in the skin, organ, and muscle.

Sometimes different varieties of the same species of fish have different safety levels.

According to the Environmental Defense Fund (EDF), for instance, Pacific (Alaska) cod has a good sustainability rating but contains moderate levels of mercury, whereas Atlantic cod generally contains low levels of mercury but has been overfished in recent decades, so it has a worse sustainability rating.

American and imported farmed catfish are both low in mercury, but only the American variety also has a high sustainability rating.

All varieties of wild and farmed shrimp are low in mercury, but only Pink shrimp from Oregon and Canadian Spot prawns get good eco ratings.

"Making informed seafood choices is one of the easiest ways to improve your own health, and that of the oceans," says Timothy Fitzgerald, Senior Policy Specialist for the Environmental Defense Fund (EDF) Oceans program.

Here are some of the more common fish ranked by EDF as the best and worst choices overall when it comes to eating safe fish that have been farmed or fished in ways that have minimal impact on the environment:

The Best Seafood Choices

  1. Albacore Tuna (U.S. and Canada)
  2. American Barramundi
  3. American Catfish
  4. Alaskan Pollock
  5. Atlantic Mackerel
  6. Bay Scallops (farmed)
  7. Clams (farmed)
  8. Crab (U.S. Snow, Dungenous, Stone)
  9. Mussels (Blue, Mediterranean, New Zealand Green)
  10. Oysters (farmed)
  11. Pacific Halibut
  12. Rainbow Trout (farmed)
  13. Sablefish, or Black Cod (U.S.)
  14. Sardines (U.S.)
  15. Tilapia (U.S., Ecuador)
  16. Wild Alaskan Salmon
  17. Yellowfin (U.S. Atlantic/pole or troll caught)

The Worst Seafood Choices

  1. Albacore Tuna (imported/longline)
  2. Atlantic Halibut
  3. Atlantic or Farmed Salmon
  4. Bluefin Tuna (imported)
  5. Caviar (imported)
  6. Shrimps and Prawns (imported)
  7. Snapper (imported)
  8. Octopus
  9. Orange Roughy
  10. Skate
  11. Sturgeon (most)
  12. Swordfish (imported)
  13. Weakfish (Seatrout)

Timothy Fitzgerald, Senior Policy Specialist for the Environmental Defense Fund, reviewed this article.



"Seafood Selector," Environmental Defense Fund, accessed June 20, 2013,

"Fish: Friend or Foe?" Harvard School of Public Health, accessed June 20, 2013,