Influence of Sampling on the Blood Chemistry of Atlantic Salmon

Blood samples were taken from laboratory-reared Atlantic salmon (Salmo salar) to determine the physiological status of the fish. The Atlantic salmon were also subjected to one of eight treatments before blood sampling to determine the influence of various handling stresses on the blood analyses. Treatments included holding the fish in nets in water or air for 2 or 4 min, or anesthesia with benzocaine, benzocaine hydrochloride, or tricaine for 3 min. Fish stunned by a blow to the head were used as controls. These treatments resulted in no major changes in selected blood chemistry characteristics: hematocrit, plasma glucose and chloride levels, and osmolality. Atlantic salmon exhibit a limited stress response to netting, as indicated by minor changes in plasma glucose concentrations.