Diffusion boundary layers ameliorate the negative effects of ocean acidification on the temperate coralline macroalga Arthrocardia corymbosa, supplement to: Cornwall, Christopher Edward; Boyd, Philip W; McGraw, Christina M; Hepburn, Christopher D; Pilditch, Conrad A; Morris, Jaz N; Smith, Abigail M; Hurd, Catriona L (2014): Diffusion Boundary Layers Ameliorate the Negative Effects of Ocean Acidification on the Temperate Coralline Macroalga Arthrocardia corymbosa. PLoS ONE, 9(5), e97235

• Main Authors: Cornwall, Christopher Edward, Boyd, Philip W, McGraw, Christina M, Hepburn, Christopher D, Pilditch, Conrad A, Morris, Jaz N, Smith, Abigail M, Hurd, Catriona L, Hofmann, Gretchen E
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2014
• Subjects: Arthrocardia corymbosa; Benthos; Biomass/Abundance/Elemental composition; Calcification/Dissolution; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Growth/Morphology; Laboratory experiment; Macroalgae; Plantae; Primary production/Photosynthesis; Reproduction; FOS Medical biotechnology; Rhodophyta; Single species; South Pacific; Temperate; Species; Identification; Maximum photochemical quantum yield of photosystem II; pH; pH, standard error; Treatment; Maximal electron transport rate, relative; Light capturing capacity; Photoinhibition; Light saturation point; Growth rate; Chlorophyll a; Chlorophyll c; Chlorophyll d; Phycocyanin; Phycoerythrin; Recruitment; Recruit size; Calcification rate of calcium carbonate; δ15N; Nitrogen, organic; δ13C; Carbon, organic, total; Carbon/Nitrogen ratio; Calcite; Proportion; Calcite saturation state; Temperature, water; Temperature, water, standard error; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Alkalinity, total; Alkalinity, total, standard error; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air, standard error; Bicarbonate ion; Bicarbonate ion, standard error; Carbonate ion; Carbonate ion, standard error; Carbon dioxide; Carbon dioxide, standard error; Diffusive boundary layer; Diffusive boundary layer, standard error; Salinity; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Experiment; Potentiometric; Calculated; Potentiometric titration; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Cornwall; Hurd; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.836665; https://doi.pangaea.de/10.1594/PANGAEA.836665

Anthropogenically-modulated reductions in pH, termed ocean acidification, could pose a major threat to the physiological performance, stocks, and biodiversity of calcifiers and may devalue their ecosystem services. Recent debate has focussed on the need to develop approaches to arrest the potential negative impacts of ocean acidification on ecosystems dominated by calcareous organisms. In this study, we demonstrate the role of a discrete (i.e. diffusion) boundary layer (DBL), formed at the surface of some calcifying species under slow flows, in buffering them from the corrosive effects of low pH seawater. The coralline macroalga Arthrocardia corymbosa was grown in a multifactorial experiment with two mean pH levels (8.05 'ambient' and 7.65 a worst case 'ocean acidification' scenario projected for 2100), each with two levels of seawater flow (fast and slow, i.e. DBL thin or thick). Coralline algae grown under slow flows with thick DBLs (i.e., unstirred with regular replenishment of seawater to their surface) maintained net growth and calcification at pH 7.65 whereas those in higher flows with thin DBLs had net dissolution. Growth under ambient seawater pH (8.05) was not significantly different in thin and thick DBL treatments. No other measured diagnostic (recruit sizes and numbers, photosynthetic metrics, %C, %N, %MgCO3) responded to the effects of reduced seawater pH. Thus, flow conditions that promote the formation of thick DBLs, may enhance the subsistence of calcifiers by creating localised hydrodynamic conditions where metabolic activity ameliorates the negative impacts of ocean acidification. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) 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 is 2014-10-13.