[I] don't think it would be illegal to tag a fish. What diffenence does it make. If you aren't tagging them you would probably eat them. Once caught they are your property and what you do with them is your business. If you are sparing their life and not harming them what is the big deal putting a tag on them. With this said I am sure there is some GOVERNMENTAL REGULATION that says no tagging ...control freaks at it again.