Several of the level 52 fishing leves require Three-Lip Carp. The fish itself is level 53... but according to everything I've found, can only be caught with a minimum of a Goblin Jig, a lure that requires FSH level 58. That makes these leves impossible to complete for someone taking them at the 'intended' level.

For that matter, forget the leve, why is a fish requiring a 58 lure placed at level 53 on the exp scale? If you have to be 58 to catch it, it shouldn't be giving you -5 levels worth of XP under any circumstances.