I think the mercury scare IS the ploy to make everyone eat less seafood.
Much like the sun apparently causes skin cancer so everyone slops sunscreen all over. It IS the sunscreen that causes skin cancer.
The sun's vit D is your friend and Big Pharma don't like it. That why they put shade sails in school, playground etc. I digress.
They use aluminium oxide to remove 97% of the fluoride.