You’ve heard the good news: Fish is a rich source of protein and omega-3 fatty acids and promotes cardiovascular and overall health. But you’re also aware of the advisories: Don’t eat too much of certain varieties, such as farmed salmon, which may contain PCBs; or other types, which may contain mercury. Add on concerns about ocean sustainability, and you may never feel sure you’re picking out the right fresh fillet at your local market.

To make the task a little less daunting, try these four online resources that guide you toward sound seafood choices both for your health and the health of the environment.

Oceans Alive
Oceans Alive, a campaign by the Environmental Defense Network, has a comprehensive website featuring seafood, human health, and environmental topics. The link Seafood Choices provides a list of the best and worst seafood selections. Eat Smart helps you weigh the benefits of versus concerns about eating seafood.

Seafood Choices Alliance
Dedicated to ocean sustainability, Seafood Choices Alliance’s website offers information on commercial fishing techniques and the most ecofriendly fish. An online database, SeaSense, tells how fish are raised and caught and gives buying tips on about 15 seafood varieties.

Food and Drug Administration (FDA)
The FDA offers the latest advisories on pathogens and contaminants found in commercial seafood. Although not the most visitor-friendly site, it is an especially good source for those worried about the risk of bacteria and food-borne illnesses from eating fish.

Environmental Protection Agency (EPA)
If you buy local fish, or if you catch your own, you can stay up-to-date on the safety of area rivers, reservoirs, and lakes by searching under your state on this EPA link. Provides advisories for contaminated or polluted fishing areas.