Sea star populations have undergone large-scale changes with recent marine heatwaves (MHW), thus identifying these taxa as vulnerable and sensitive to climate extremes. This project would support a developing collaboration with UVic Amanda Bates' laboratory to study impacts of climate change on understudied marine organisms. Specifically, this project would support an experiment that will evaluate 1) how environmental extreme events - marine heatwaves - affect the survival and physiological performance of Dermasterias imbricata (Leather seastar) and 2) whether nutritious state (i.e., access to plenty of food vs food scarcity) can mitigate, ameliorate or exacerbate the expected detrimental effects of exposure to thermal stress. This experiment will target Leather seastar populations around Quadra Island, BC. 150 organisms will be transferred to the Marna Wet Lab on Quadra Island, BC, semi-quarantined, then exposed to control temperatures (15oC) and warm temperatures (>20oC) for 15 days. Half of the organisms will be starved, while the other half will have access to food ad libitum. Survival, morphometrics, coelomocyte counts (a proxy for immune response), righting time and other physiological status metrics will be evaluated throughout the experiment to evaluate responses to stressors. Transcriptomic samples will be collected while additional funding is secured for their analysis. Sea stars will be collected and quarantined in September 2024 and the experiment will take place in October 2024. The results of this study will provide valuable baseline information regarding the physiological responses to environmental stress of a key seastar species, as well as build fundamental knowledge for predicting how sea star populations will respond to future climate change scenarios.