The eastern oyster (Crassostrea virginica) represents a growing industry in the US and in other locales. As a “blue food”, oysters are a sustainable source of nutrition with limited associated environmental burden. A major limitation to oyster production, however, are the dynamic environments in which they are cultivated. With a large natural geographic distribution, the eastern oyster can tolerate a wide range of temperature and salinity variation, but these fundamental changes have large consequence for production. Further understanding the metabolic costs associated with environmental variation and the mechanisms employed to cope with them is a first step in the identification of biomarkers relevant to maintain and enhance production. As global temperatures continue to increase, coastal zones are experiencing increased storm activity and receiving un-paralleled volumes of rainfall in short periods of time. The resultant coastal flooding can cause acute but substantial departures from ambient salinities along estuarine habitats where oysters are cultivated. Here the impacts of acute salinity changes on the respiratory and metabolic activity of early-juvenile eastern oysters (<10 mm), a critical bottleneck in the life-history of this species that are vulnerable to environmental variation, are quantified. Individual juveniles were incubated in calibrated respiration vials at 15 and 25°C across a salinity gradient (5-32) to determine impacts on respiration Q10 (see Figure) and changes in mass-specific metabolism. As salinity decreased to 15, respiration Q10 was elevated relative to higher salinity treatments, representing an increase in mass-specific metabolism associated with maintaining ion homeostasis. At salinities below 15, respiration Q10 was similar to that of higher salinity treatments but was associated with decreased valve opening and activity. Future studies identifying how the resultant energy is allocated along salinity gradients will provide insight into resilience to environmental stress and the strategies that organisms use to mitigate those limitations.