Joel asks Ed to hand him the spear because he is going spear fishing. Ed hands him a gaff hook, something that you wouldn't fish with because that's the hard way to go about spear fishing. On top of the difficulty, it is illegal in most states to snag fish, exceptions might be made for native Americans, but Joel would not qualify for this.
Ed supposedly travels up a tributary to get to the settlement but is shown approaching from up-river, with the current.