I have read a couple of forms and people complaining about fishing.
lets break it down
fishing is a bit random and confusing, according to the wiki certain actions should work on a certain kind of fish but if you use, "pull hard" twice in a row, once you could start leaning back (indicating you are getting the fish) and the second time you could lose the fish.
problem: its complicated to know if you are doing it right and boring
solution:
a catch balance meter. imagine a leveler (you know the type a carpenter would use to keep things level) the objective of the mini game will be to keep the leveler between two points (possibly that shrink as the fish reels in). add in dance dance style (hit this key now) type game play (IE W, A, S, D) will appear on the screen to hit that key to bring in the fish.