Linkages Between Upwelling and Shell Characteristics of Mytilus californianus: Morphology and Stable Isotope (δ13C, δ18O) Signatures of a Carbonate Archive from the California Current

Friday, 19 December 2014
Jessica D Hosfelt1,2, Tessa M Hill1,2, Ann D Russell1, Jessica Rebecca Bean3,4, Eric Sanford2,5 and Brian Gaylord2,5, (1)University of California Davis, Department of Earth and Planetary Sciences, Davis, CA, United States, (2)Bodega Marine Laboratory, UC Davis, Bodega Bay, CA, United States, (3)Museum of Paleontology, UC Berkeley, Berkeley, CA, United States, (4)University of California Davis, Department of Anthropology, Davis, CA, United States, (5)University of California Davis, Department of Evolution and Ecology, Davis, CA, United States
Many calcareous organisms are known to record the ambient environmental conditions in which they grow, and their calcium carbonate skeletons are often valuable archives of climate records. Mytilus californianus, a widely distributed species of intertidal mussel, experiences a spatial mosaic of oceanographic conditions as it grows within the California Current System. Periodic episodes of upwelling bring high-CO2 waters to the surface, during which California coastal waters are similar to projected conditions and act as a natural analogue to future ocean acidification. To examine the link between upwelling and shell characteristics of M. californianus, we analyzed the morphology and stable isotope (δ13C, δ18O) signatures of mussel specimens collected live from seven study sites within the California Current System. Morphometric analyses utilized a combination of elliptic Fourier analysis and shell thickness measurements to determine the influence of low pH waters on the growth morphology and ecological fitness of M. californianus. These geochemical and morphological analyses were compared with concurrent high-resolution environmental (T, S, pH, TA, DIC) records from these seven study sites from 2010-2013. With appropriate calibration, new archives from modern M. californianus shells could provide a valuable tool to enable environmental reconstructions within the California Current System. These archives could in turn be used to predict the future consequences of continuing ocean acidification, as well as reconstruct past (archeological) conditions.