Telltale Signs That Your Fish Has Gone Bad. Story by Cara J Suppa • 5mo. ... Of course, fish smells like fish to begin with, but it should be a mild scent, like the salty sea air.

If your "fresh" fish has a bad odor, it's not as fresh as you think. So, if you do get a whiff of something ugly from a fresh catch, it should hit the bin.