A method of slaughtering fish comprising the steps of providing an elongated passage, passing fish entrained within a flow of water through said passage, and generating linear electric field in the water along at least a first region of said passage, thereby inducing electro-anaesthesia or stunning of the fish passing through said first region of the passage, and applying a further electric field in the water in a subsequent region of the passage, downstream of said first region, to kill the fish such that the fish exit a downstream end of said passage in a dead state.