When God destroyed the world with a flood, he saved Noah because he was a virtuous man.  He also saved two of every animal, and presumably managed to pick the two good ones in the process.

But what about the fish?

The fish wouldn’t have been bothered by the flood, and they would have all survived (minus a few that got caught over land when the flood receeded, I suppose).  So the question we are left with is this:

Are fish evil?