Juvenile Dungeness Crabs Reared in High CO2 Have Higher Base Metabolic Rates

Erin Tully1, Kelsey Donahue2, Danielle Perez3, Kate Rovinski3, Mike Maher4, Emma Reinhardt1 and Paul Mcelhany3, (1)Office of Education, NOAA, Ernest F. Hollings Undergraduate Scholarship, Silver Spring, MD, United States, (2)Washington State Department of Transportation, Seattle, WA, United States, (3)Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Conservation Biology Division, Mukilteo, WA, United States, (4)NOAA Northwest Fisheries Science Center, Mukilteo, WA, United States
Ocean acidification (OA) is an caused by increasing anthropogenic CO2 absorbed by the ocean which produces chemical changes leading to decreasing pH. This drop in pH levels will likely cause shifts in abundance or distribution of species that are of vital ecological and economical importance. In the Pacific Northwest, the Dungeness crab, Cancer magister, is a commercially important species. Under short-term exposures to low pH, Dungeness crab zoea have shown lower survival and slower developmental rates (Miller et. al, 2016). This study examined how CO2 concentration treatments affected the respiration rate of juvenile Dungeness crabs. It was hypothesized that long term exposure to low pH will affect the crabs’ metabolic activity. In this study, we used respirometry, which measured oxygen consumption in a closed jar, to examine the metabolic sensitive of C. magister to high and low CO2 treatments. The juveniles used in this study were exposed to two CO2 treatments (ambient and high CO2) for 300 days. In preparation for the respirometry trials, crabs were starved 24 hours prior and weighed the morning of their trial. Preliminary analysis shows a significant effect of high CO2 treatment in increasing respiration rate. Separate analyses indicate that CO2 treatments affected the size of the crabs in this study, suggesting complicated trade-offs in maintaining metabolic rate in a high CO2 environment and energetic resource allocation.