I recently downloaded the Monterey Bay Aquarium app for my iPhone. It’s a great way for those of us who want to buy sustainable seafood to know what’s ok and what’s not. Only a few fish get the designation “Best Choice”–most fish, like monkfish, cod, flounder, and skate are to be avoided, and other fish like haddock, hake, and pollock are “Good Alternatives”–but “Best Choice”? That’s an exclusive designation. And I was surprised to see, while checking the app at Citarella, that catfish–which is actually pretty cheap–is a “Best Choice” fish.