Effects of temperature change on stress parameters in Atlantic salmon (Salmo salar) smolt

This study was designed to compare hormonal responses in saltwater-acclimated Atlantic salmon (Salmo salar) smolt subjected to a gradual (1C degree /day for 5 days) or acute (5C degree /day) temperature change from their ambient conditions to determine whether a stress response was elicited. Plasma concentrations of electrolytes, glucose, cortisol, and T sub(4) did not change in response to temperature alterations, either gradual or acute. Any changes that occurred (i.e., increased cortisol and glucose concentrations) were likely the result of handling stress. It appears unlikely that a 5C degree temperature change within the `optimal' range would cause stress to Atlantic salmon smolt.