Sell monkfish for up
You can now fish the great sharks. Be warned though as sharks are extremely slow at level 76, so I suggest fishing lobbys or monkfish till about 80+ fishing, then start fishing sharks for that bit of money. If you just want to get 99 fishing out of the way then go back fly fishing at Phoenix Dynasty Money, remember you can still make a bit of money fly fishing! Another great way is to fish Monkfish at Piscatoris Fishing Colony. You can sell monkfish for up to 400gp each and are the same speed as lobsters, but give much more XP.