I've never thought about it before, but does the fish you eat after fishing affect your performance "in a special way"? In the sense that fish are now just a resource for weight gain, or does each of them have some effects that are not directly mentioned?
Viewing post in The Curse Of Something comments
The fish are just a food source for now. Nothing special. And the Curse Encyclopedia is a quest reward item so its location is random. You can either get it from the Winner's quest board, as a special at the store, from a chest near the castle, or from completing the scene in the ship with the Alligator Pirate