It is broadly thought that populations can persist under changing environmental conditions through phenotypic plasticity, physiological acclimation, and ultimately intergenerational adaption. Yet, research rarely incorporates intraspecific variation in physiological responses to environmental change, often making species-level inference on the response of a single population. Here, we synthesise empirical data collected from a warm-edge population with published data on key physiological performance indicators for a keystone and broadly distributed marine species – Euphausia pacifica - across latitudinal gradients on both sides of the north Pacific Ocean (30-50°N). Despite the importance of this species for pelagic and commercial food webs, the environmental drivers of changes in physiological traits such as metabolic rate have not been quantified for different populations of this species across large parts of its range. We correlated gradients of dissolved oxygen and temperature with inter-population differences in respiration, total length, life-span and growth using generalised additive mixed-models. Our synthesis suggests that the physiological traits we analysed were more strongly correlated with surface oxygen concentration than sea-surface temperature or experimental temperature. Across latitudinal gradients, there was evidence for metabolic cold adaptation in the respiration rate of this species, however due to large covariation in oxygen and temperature across its range, it is unclear whether respiration rate in this species is constrained by oxygen availability or temperature and is likely related to both. This species shows high levels of local acclimation, with implications for the resilience of the species to warming and hypoxia, both of which are predicted to increase in near-future climate change scenarios in line with stronger El Niño-Southern Oscillation (ENSO) and marine heatwaves.