UTILIZING BIOLOGGERS TO INFER BEHAVIOUR AND PHYSIOLOGY OF COMMERCIAL ATLANTIC SALMON (SALMO SALAR)

Abstract

There is a growing global market for Atlantic salmon (Salmo salar). Stakeholders have a vested interest in the future of commercial operations considering the ongoing and future impacts of ocean warming as it relates to fish stress and welfare. These challenges necessitate a thorough understanding of thermal stress and confounding variables specific to commercial farming. Fish were tagged using two types of biologgers measuring temperature, heart rate, external acceleration, and depth of fish during seasonal extremes. Optimal temperature was estimated at 12.7 °C, with observed reductions in heart rate scope at extreme temperatures, indicating thermal stress. Fish displayed signs of both secondary and tertiary stress in response to a short- and long-term heat event, and both heart rate and acceleration increased in response to feeding but displayed a more nuanced response to operations. This thesis demonstrates how biologgers could inform farm management and enhance fish welfare in commercial aquaculture.