Sustainable ethically sourced produce is the start of good cooking. You just can't turn rubbish into a good dish. If I don't know where my food comes from and the impact caused by its production, then I am already a little reluctant to cook with it. With most produce the decisions boils down to whether you are prepared to pay a fair price to producers who are doing the right thing. Generally their product will taste better, so it's win-win for all parties...
Sustainable, ethically sourced seafood however is one area that can easily fall off the radar; kind of, out of sight out of mind. In the past I have had fish on my menus that really were "no go-s" but I had no idea. Access to simple, understandable impartial data on seafood species sustainability can be problematic. If this interests you, Hilary McNevin has written an amazing little guide with 23 species covered , along with recipes , seasonality notes and some good general all round seafood tips, and it's an easy read!: Guide to Fish.
For more information on sustainable fishing check out: www.msc.org/ssd