title: The role of temperature in determining species' vulnerability to ocean acidification: a case study using Mytilus galloprovincialis.
abstract: Ocean acidification (OA) is occurring across a backdrop of concurrent environmental changes that may in turn influence species' responses to OA. Temperature affects many fundamental biological processes and governs key reactions in the seawater carbonate system. It therefore has the potential to offset or exacerbate the effects of OA. While initial studies have examined the combined impacts of warming and OA for a narrow range of climate change scenarios, our mechanistic understanding of the interactive effects of temperature and OA remains limited. Here, we use the blue mussel, Mytilus galloprovincialis, as a model species to test how OA affects the growth of a calcifying invertebrate across a wide range of temperatures encompassing their thermal optimum. Mussels were exposed in the laboratory to a factorial combination of low and high pCO2 (400 and 1200 µatm CO2) and temperatures (12, 14, 16, 18, 20, and 24°C) for one month. Results indicate that the effects of OA on shell growth are highly dependent on temperature. Although high CO2 significantly reduced mussel growth at 14°C, this effect gradually lessened with successive warming to 20°C, illustrating how moderate warming can mediate the effects of OA through temperature's effects on both physiology and seawater geochemistry. Furthermore, the mussels grew thicker shells in warmer conditions independent of CO2 treatment. Together, these results highlight the importance of considering the physiological and geochemical interactions between temperature and carbonate chemistry when interpreting species' vulnerability to OA.
authors.affiliation: Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, United States of America.
authors.forename: Kristy J
authors.initials: KJ
authors.lastname: Kroeker
authors.affiliation: Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, United States of America; Department of Evolution and Ecology, University of California Davis, Davis, California, United States of America.
authors.forename: Brian
authors.initials: B
authors.lastname: Gaylord
authors.affiliation: Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, United States of America; Department of Geology, University of California Davis, Davis, California, United States of America.
authors.forename: Tessa M
authors.initials: TM
authors.lastname: Hill
authors.affiliation: Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, United States of America.
authors.forename: Jessica D
authors.initials: JD
authors.lastname: Hosfelt
authors.affiliation: Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, United States of America.
authors.forename: Seth H
authors.initials: SH
authors.lastname: Miller
authors.affiliation: Bodega Marine Laboratory, University of California Davis, Bodega Bay, California, United States of America; Department of Evolution and Ecology, University of California Davis, Davis, California, United States of America.
authors.forename: Eric
authors.initials: E
authors.lastname: Sanford
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D057231:Climate Change; D005247:Feeding Behavior; D049878:Mytilus / Q000502:physiology*; D009792:Oceans and Seas; D011157:Population Dynamics; D012623:Seawater / Q000737:chemistry*; D013696:Temperature
chemical_list: D002245:Carbon Dioxide