Right now, most cooked fish recipes -- including the new ones for pike and shellfish, and presumably shark -- award 3XP/each when cooked. The exception is fish (other than pike) from Frozen Fjord -- tuna, grayling, and char all give 4XP when cooked.
I'd like it if pike, shark, and shellfish recipes could be updated to give 4XP as well.
Edit: And since I left out my reasoning on this: If we already have a standard that higher-level fish give more XP when cooked, let's keep to that one versus bringing all fish down to 3XP. It makes getting your fishing up a little more rewarding by speeding up your cooking leveling.