Always thought it was weird chum didn’t have a use since there are fishing zones. Since chum gives the “biting” effect irl then I’d say allow players to donate to each fishing zone similar to how we donate to the community center. When the required amount is reached, that zone gets “biting” for 10 mins, after which it resets and you can do it again.
Now that players can trigger “biting” you can also add a fishes that can only be caught during “biting”. That way it will give both new players and t250 players a reason to use the system.