These days it's tricky enough navigating the terrain of seafood for health concerns, much less moral ones. Plenty of organizations have compiled comprehensive lists of good and not-so-good fish to eat, depending on whether the fish are imperiled, how they're caught, their overall health, and other factors.
But let's say you're out at a restaurant and there's fish on the menu (for example, the buttermilk fried calamari that was on the menu when I was dining out last weekend) but you forgot your geeky pocket-sized sustainable fish reference guide. Feel caught in a moral quagmire? Simply get out your cell phone and text "fish" and the name of the fish to 30644. You'll get a text informing you about the fish's sustainability.
I tried the service and within seconds got a text back telling me:
squid; (GREEN) few environmental concerns; squid grow quickly making them resistant to fishing pressure
So I forged ahead, and the squid didn't disappoint.
If your choice isn't "green," the text will provide you with alternatives. This nifty service is offered by the Blue Ocean Institute.