The effects of elevated temperature and dissolved ρ CO 2 on a marine foundation species

Abstract

Understanding how climate change and other environmental stressors will affect spe- cies is a fundamental concern of modern ecology. Indeed, numerous studies have documented how climate stressors affect species distributions and population persis- tence. However, relatively few studies have investigated how multiple climate stress- ors might affect species. In this study, we investigate the impacts of how two climate change factors affect an important foundation species. Specifically, we tested how ocean acidification from dissolution of CO2 and increased sea surface temperatures affect multiple characteristics of juvenile eastern oysters (Crassostrea virginica). We found strong impacts of each stressor, but no interaction between the two. Simulated warming to mimic heat stressed summers reduced oyster growth, survival, and filtra- tion rates. Additionally, we found that CO2-induced acidification reduced strength of oyster shells, which could potentially facilitate crab predation. As past studies have detected few impacts of these stressors on adult oysters, these results indicate that early life stages of calcareous marine organisms may be more susceptible to effects of ocean acidification and global warming. Overall, these data show that predicted changes in temperature and CO2 can differentially influence direct effects on individ- ual species, which could have important implications for the nature of their trophic interactions.