HANDLING STRESS AND WATER-QUALITY DURING LIVE TRANSPORTATION AND SLAUGHTER OF ATLANTIC SALMON (SALMO-SALAR)

Atlantic salmon (Salmo salar), mean weight 5.1 kg, were transported li ve for 1.5 h by a well-boat (fish density 125 kg m(-3)) from the seaca ge to a fish processing plant and then kept in the well-boat for 4 h p rior to slaughter. Anaerobic white muscle activity due to handling str ess during fish loading at the cage, after shipment immediately before slaughter, and after the fish had passed the slaughter line, was eval uated using high-energy phosphates and IMP, the [ATP:IMP] ratio, adeny late energy charge together with pH and redox potential measured direc tly in the muscle. Water quality parameters, pH, salinity, temperature , dissolved oxygen, carbon dioxide, total carbonate carbon, total alka linity, ammonia and ammonium were monitored at the cage, during shipme nt, and in the carbon dioxide anaesthesia tank during commercial fish slaughter. No dramatic effects of handling stress were found, indicati ng that transport and slaughtering did not have an adverse effect on f lesh quality. The results were explained by the ability of the well-bo at to maintain good seawater quality during transport, to a quick bulk netting of the fish from well-boat to the slaughter line and to an ef ficiently run carbon dioxide anaesthesia-tank that minimised strugglin g prior to killing.