Seawater carbonate chemistry and percentage cover of macroalgal species at three locations at Vulcano, Italy, supplement to: Cornwall, Christopher Edward; Revill, Andrew T; Hall-Spencer, Jason M; Milazzo, Marco; Raven, Robert J; Hurd, Catriona L (2017): Inorganic carbon physiology underpins macroalgal responses to elevated CO2 at three locations at Vulcano, Italy. Scientific Reports, 7, 46297

• Main Authors: Cornwall, Christopher Edward, Revill, Andrew T, Hall-Spencer, Jason M, Milazzo, Marco, Raven, Robert J, Hurd, Catriona L
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2017
• Subjects: Acetabularia acetabulum; Benthos; Caulerpa prolifera; Caulerpa racemosa; CO2 vent; Coast and continental shelf; Codium bursa; Community composition and diversity; Cystoseira barbarta; Cystoseira brachycarpa; Cystoseira compressa; Cystoseira crinita; Cystoseira foeniculacea; Cystoseira foeniculata; Dictyopteris polypodioides; Dictyota dichotoma; Dilophus fasciola; Entire community; Field observation; Halopteris scoparia; Jania rubens; Mediterranean Sea; Padina pavonica; Rocky-shore community; Sargassum muticum; Temperate; Udotea petiolata; Event label; Type; Figure; Table; Species; Registration number of species; Uniform resource locator/link to reference; Site; Mass; Lipid content; pH; Oxygen; Coverage; Location; Season; δ13C; Years; Salinity; Temperature, water; pH, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbon dioxide; Carbon dioxide, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; δ13C, standard deviation; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Calcite saturation state; Experiment; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Cornwall; Hurd; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.884805; https://doi.pangaea.de/10.1594/PANGAEA.884805

Beneficial effects of CO2 on photosynthetic organisms will be a key driver of ecosystem change under ocean acidification. Predicting the responses of macroalgal species to ocean acidification is complex, but we demonstrate that the response of assemblages to elevated CO2 are correlated with inorganic carbon physiology. We assessed abundance patterns and a proxy for CO2:HCO3- use (delta 13C values) of macroalgae along a gradient of CO2 at a volcanic seep, and examined how shifts in species abundance at other Mediterranean seeps are related to macroalgal inorganic carbon physiology. Five macroalgal species capable of using both HCO3- and CO2 had greater CO2 use as concentrations increased. These species (and one unable to use HCO3-) increased in abundance with elevated CO2 whereas obligate calcifying species, and non-calcareous macroalgae whose CO2 use did not increase consistently with concentration, declined in abundance. Physiological groupings provide a mechanistic understanding that will aid us in determining which species will benefit from ocean acidification and why. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2018-01-12.