What The vertebrate gill is a multifunctional organ that functions in both gas-exchange, iono-regulation and acid/base-balance. The gill displays a tremendous phenotypic plasticity, where it can increase the capacities for those functions in response to changes in environmental conditions. However, spatial constraints within the gill enforces it to prioritise between physiological modalities depending on the environmental context. The overall goal of my research project is to identify how fishes prioritise gas-exchange and iono-regulation at the gill when faced with different combinations of environmental stressors, and to determine the physiological, cellular and genetic mechanisms underpinning those tradeoffs. Why Animals in the wild are constantly moving and are faced with changes in multiple environmental factors. While much is known regarding the specific mechanisms involved in acclimation to individual environmental conditions, very little is known about the pathways and trade-offs associated with exposure to several challenges simultaneously. This research project aims to identify these in order to provide a mechanistic understanding of how animals acclimate to naturally occurring conditions. How Salmon will be acclimated to hypoxia, high temperature, or exercise after a long-term acclimation to salinities ranging from freshwater to seawater. Using animals instrumented with arterial and urinary bladder catheters, changes in internal blood gas - and ion status will be monitored, while simultaneously measuring gill and kidney function via the use of radiolabelled isotopes. In addition, immunoblotting, RNA-seq, and immunohistochemistry will be used to identify the cellular and molecular bases for the physiological trade-offs found in the in vivo studies. The project is being conducted in Colin Brauner's lab at The University of British Columbia, Canada. SSR Salmon are of major cultural and economic significance throughout the world, and the results of this project can be used in conservation management of salmon. In addition, the project will help to identify optimal rearing conditions for land-based aquaculture to increase production efficiency and animal welfare, as well as to reduce environmental impact.