How to Buy Sustainable Fish

Look for the label of the Marine Stewardship Council. From their website;

Sustainable fishing

Throughout the world there are fisheries using good management practices to safeguard jobs, secure fish stocks for the future and help to protect the marine environment. At the Marine Stewardship Council, we believe that sustainable fishing is a powerful solution. We want to see well managed fisheries recognised and rewarded, and we want to encourage more fisheries to join them. Through our certification and ecolabelling program we seek to reverse the decline of fish stocks, safeguard livelihoods and deliver improvements in marine conservation worldwide. Our blue ecolabel makes it easy for everyone to make the best environmental choice in seafood.

I saw this at The Green Miles, which also links to the Monterey Bay Aquarium pocket seafood guide.