Caught the same summer run steelie last year that broke my buddy off two weeks earlier. Hook was still there with about 10" of line hanging out her mouth. No sign of rust or corrosion whatsoever and I removed both hooks from the fish and sent her back.

Nickel finished hooks will rust and deteriorate much quicker than NSB (black) or annodized (red, blue, green).

I see a lot of punk rockers with piercings all over their face and God knows where else. They all seem to be doing fine with a face full of metal so I'm sure that hooks just become "jewelry" when left on the fishes face and might even help attract mates when spawning I know that I like to spawn with pretty girls who have tongue rings