Seriously, in the LJ cooking community, someone posted this link:
Monterey Bay Aquarium - Seafood Watch
Now, I knew not to eat Chilean sea bass and swordfish, but didn't know about salmon (no loss, as I don't like salmon much and David hates it) or about orange roughy.
At least eel still appears to be okay. Still, I'll have to print this out and keep it handy when going out for sushi.