Time for the "I made a stupid mistake and I wanna gripe about it" thread. I finished Go Fish and came very close several times to getting killed by the narsty fishies. I was so pissed off by this that I killed the quest giver after he gave me the waterbreathing ring. Unfortunately now I'm stuck for the rest of the game with a dozen scales I can't use and can't get rid of. Luckily they don't weigh anything so they aren't going to be a problem encumbrance-wise; it's just annoying. Adding insult to injury, the twit didn't even have that much in his 'retirement fund' - less than 30 gold. Beats me how he intended to live on that dinky little nest egg.
More likely you looted the scales back from him. Also, if you're on the PC, don't waste the effort to resurrect him, just use the console to remove the scales.