the artisan fishing quest is non faction. u need to start the quest from the fishing trainer in IF i believe, then u will need a find a human fishing on one of the small islands south of the theramore isle, he will ask u to fish out 4 fish from 4 diff places. Horde's trainer will also send players to the same npc. good luck.
I believe someone has compiled all the info on the blizz trade forums.