The tackle box is found at a small "camp" in ZG.  If you go to the back side of the center temple left hand side corner there is a spot with a tent and some supplies also some bottles that when you open them you get Darkmoon Special Reserve.  There is a small box that when you mouse over it it will show you the quest ! symbol.  Each person in the raid or party will be able to get the quest from the tackle box. The camp is on the outside of the mote going around the temple.