title: Next-century ocean acidification and warming both reduce calcification rate, but only acidification alters skeletal morphology of reef-building coral Siderastrea siderea.
abstract: Atmospheric pCO2 is predicted to rise from 400 to 900 ppm by year 2100, causing seawater temperature to increase by 1-4 °C and pH to decrease by 0.1-0.3. Sixty-day experiments were conducted to investigate the independent and combined impacts of acidification (pCO2 = 424-426, 888-940 ppm-v) and warming (T = 28, 32 °C) on calcification rate and skeletal morphology of the abundant and widespread Caribbean reef-building scleractinian coral Siderastrea siderea. Hierarchical linear mixed-effects modelling reveals that coral calcification rate was negatively impacted by both warming and acidification, with their combined effects yielding the most deleterious impact. Negative effects of warming (32 °C/424 ppm-v) and high-temperature acidification (32 °C/940 ppm-v) on calcification rate were apparent across both 30-day intervals of the experiment, while effects of low-temperature acidification (28 °C/888 ppm-v) were not apparent until the second 30-day interval-indicating delayed onset of acidification effects at lower temperatures. Notably, two measures of coral skeletal morphology-corallite height and corallite infilling-were negatively impacted by next-century acidification, but not by next-century warming. Therefore, while next-century ocean acidification and warming will reduce the rate at which corals build their skeletons, next-century acidification will also modify the morphology and, potentially, function of coral skeletons.
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 United States of America.
authors.forename: Kimmaree M
authors.initials: KM
authors.lastname: Horvath
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 United States of America.
authors.forename: Karl D
authors.initials: KD
authors.lastname: Castillo
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 United States of America.
authors.forename: Pualani
authors.initials: P
authors.lastname: Armstrong
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 United States of America.|Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts 01908, United States of America.
authors.forename: Isaac T
authors.initials: IT
authors.lastname: Westfield
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 United States of America.|Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts 01908, United States of America.
authors.forename: Travis
authors.initials: T
authors.lastname: Courtney
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3300 United States of America.|Department of Marine and Environmental Sciences, Northeastern University, Nahant, Massachusetts 01908, United States of America.
authors.forename: Justin B
authors.initials: JB
authors.lastname: Ries
mesh_terms: D000143:Acids / Q000737:chemistry; D000818:Animals; D037421:Anthozoa / Q000033:anatomy & histology* / Q000502:physiology*; D002113:Calcification, Physiologic; D057894:Coral Reefs; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry*
chemical_list: D000143:Acids