Species distribute themselves in the environment to maximize fitness, within their physiological and ecological constraints. The influence of dissolved oxygen and temperature on habitat use in marine systems, as well as their interactive effects on metabolic activity, all considerably impact habitat availability. Yet, despite their importance, a species’ physiology is rarely directly considered in species distribution models for marine species.

Temperature and oxygen jointly set physiological limits on marine species fitness, and yet the degree to which these factors also limit the habitat use of marine species remains unclear. Here, we used satellite tracking data across twelve years and 70 immature shortfin mako sharks (Isurus oxyrinchus) in the Northeast Pacific to develop species distribution models following boosted tree frameworks to investigate the factors that contribute to their habitat suitability. We evaluated the inclusion of both dissolved oxygen and the Aerobic Growth Index (AGI), a new metric that directly considers metabolic demands. Model performance was assessed using metrics including the Area Under the receiver operative Curve (AUC), and percent deviance explained, and we found that dissolved oxygen and the AGI considerably improved predictive performance (ΔAUC_{dissolved oxygen} = 0.05~~; ΔAUC_AGI = 0.05) and explanatory power (Δ% Deviance Explained_{dissolved oxygen} = 10.2; Δ% Deviance Explained_AGI = 9.7) of habitat suitability models. In addition, species habitat predictions, including the AGI, uniquely predicted low habitat suitability during La Niña events (i.e., periods associated with oxygen-poor conditions) in the Pacific North Equatorial Current, and region known to be metabolically stressful for this species. Ocean warming and deoxygenation are progressing across much of the global ocean, which will have direct impacts on metabolic habitat availability. Thus, accounting for these changes together will improve understanding of habitat availability, contribute to climate-ready management tools across international boundaries, and support more robust conservation planning.