Aspects of animal welfare protection at stunning and slaughter procedures of fish

Animal welfare provisions define stunning and slaughter procedures for fish intended for human consumption in Germany. With respect to stunning and the slaughter of fish, these national regulations go far beyond EU regulations. However, especially with regard to new aquaculture species (e.g. African Catfish), the suitability of fish stunning and killing methods approved by German law must be particularly questioned. Adspective findings, such as the loss of equilibrium or absence of the vestibulo-ocular reflex are important for the assessment of stunning or killing methods from the point of view of animal welfare. Nevertheless, an animal welfare assessment of fish stunning or killing methods based on adspective findings can not be achieved for all fish species. The stunning of fish by means of a percussive blow must be classified as a humane method. However, this method can not be applied to all fish species or for the stunning of larger fish quantities. Electrical stunning or the administration of anesthetic drugs can be generally classified as humane methods as well. Nevertheless, the electrical stunning is not applicable to all fish species. Furthermore there is a lack of scientific knowledge and a necessity for setting up standards in relation to the current parameters to be used for electrical stunning. For legal reasons, the use of anaesthetic substances for stunning or killing of fish for food purposes is not possible in Germany. The use of carbon dioxide for the stunning or killing of salmonids should be considered as not humane. The legal animal welfare regulations in Germany provide only a limited suitable framework for stunning or killing of fish intended for human consumption under field conditions. Especially for new aquaculture species there is a need for the development of animal welfare compatible methods for stunning and/or killing of fish under practical conditions as well as for the establishment of standards, especially for the application of electrical stunning methods. The carbon dioxide exposure should be deleted as an approved method for stunning or killing of salmonids.