Salmon is usually not a problem because they do not live all that long. Cod is only has slightly more mercury.
Bigeye tuna and swordfish are the worse as far as I know but I could be wrong.
Thank you very much.
I was quite wrong about salmon. Now looked it up and 3 servings a week are safe and more can be tolerate without problems.
I was misinformed. Thank goodness for FR and you.
How about catfish? I recently came upon in in New Orleans. Yum but the heck with it it if it has poisonous stuff in it.