At my job, I sometimes have to fill out maps with PCB levels found in fish caught in dirty rivers. It is pretty scary.
I have a friend and I went out to eat with her once. Salmon was the special, she asked where it was from. "Atlantic Salmon" She refrained from ordering it. I was amazed at her knowledge, and for those of us who can't keep this information in our heads, here is a pocket guide:
http://www.edf.org/documents/1980_pocket_seafood_selector.pdf a complete list is here
http://www.edf.org/page.cfm?tagID=1540 We stopped buying crawfish at Kroger when we saw they were raised in China. Living in the southern US and getting your rice and crawfish from China is insane.