Anesthesia during Vaccination of Atlantic Salmon: Compliance with Recommended Procedures

Abstract

The preparation and use of two anesthetic agents for fish, a buffered metacaine solution for anesthesia in connection with vaccination procedure, and an available benzocaine solution for minor procedures, were studied at a commercial fish farm producing Atlantic salmon, Salmo salar L., smolts. The procedures were compared with the given recommendations to evaluate compliance with recommended procedures and labels. The personnel were evaluated to be non-compliant with labels and procedures for both anesthetic agents used and the recommended exposure time in the baths. Five important themes were identified: the preparation and use of the anesthetics, fish welfare, training procedures, and occupational hazard aspects. One important reason for non-compliance was that the rate of delivery of anesthetized fish to the vaccination table was more dependent on the speed of vaccination, and less on the anesthetic depth of the fish. This may be a management issue. Management decisions may create an environment leading to situations where errors are more likely to occur. Better communication between the fish health-service team and the personnel, more tailored procedures, and a preprepared anesthetic agent might increase compliance with procedures and may promote fish welfare and welfare of the employees.