It would just make good sense to put the guts and entrails back into the same river that you caught your fish from. Many fish diseases are carried in these body parts, and one should not pass them into other river systems if at all possible. I always clean, and gut my fish in the same river it was caught in.

When we used to "pump" fish from our rearing ponds into the Cowlitz, we always had to first disinfect the pumps before we could use them. Fish carry lots of bad "stuff" that don't bother humans, but can be disastrous to other fish. Maybe one of our local biologist will jump in and name a few like C-Shasta or IHN, etc.

Cowlitzfisherman