Decreased light availability can amplify negative impacts of ocean acidification on calcifying coral reef organisms, supplement to: Vogel, Nikolas; Meyer, Friedrich Wilhelm; Wild, Christian; Uthicke, Sven (2015): Decreased light availability can amplify negative impacts of ocean acidification on calcifying coral reef organisms. Marine Ecology Progress Series, 521, 49-61

• Main Authors: Vogel, Nikolas, Meyer, Friedrich Wilhelm, Wild, Christian, Uthicke, Sven
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2015
• Subjects: Acropora millepora; Animalia; Benthic animals; Benthos; Bottles or small containers/Aquaria <20 L; Calcification/Dissolution; Chlorophyta; Cnidaria; Coast and continental shelf; Growth/Morphology; Halimeda opuntia; Laboratory experiment; Light; Macroalgae; Plantae; Primary production/Photosynthesis; Respiration; Single species; South Pacific; Tropical; Event label; Species; Treatment; pH; Irradiance; Identification; Calcification rate of calcium carbonate; Net photosynthesis rate, oxygen; Respiration rate, oxygen; Gross photosynthesis rate, oxygen; Chlorophyll a; Growth rate; pH, standard deviation; Temperature, water; Temperature, water, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbon dioxide; Carbon dioxide, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Salinity; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Calcite saturation state; Experiment; Potentiometric; Potentiometric titration; Calculated using CO2calc; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Sven; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.846877; https://doi.pangaea.de/10.1594/PANGAEA.846877

Coral reef organisms are increasingly and simultaneously affected by global and local stressors such as ocean acidification (OA) and reduced light availability. However, knowledge of the interplay between OA and light availability is scarce. We exposed 2 calcifying coral reef species (the scleractinian coral Acropora millepora and the green alga Halimeda opuntia) to combinations of ambient and increased pCO2 (427 and 1073 µatm, respectively), and 2 light intensities (35 and 150 µmol photons/m**2/s) for 16 d. We evaluated the individual and combined effects of these 2 stressors on weight increase, calcification rates, O2 fluxes and chlorophyll a content for the species investigated. Weight increase of A. millepora was significantly reduced by OA (48%) and low light intensity (96%) compared to controls. While OA did not affect coral calcification in the light, it decreased calcification in the dark by 155%, leading to dissolution of the skeleton. H. opuntia weight increase was not affected by OA, but decreased (40%) at low light. OA did not affect algae calcification in the light, but decreased calcification in the dark by 164%, leading to dissolution. Low light significantly reduced gross photosynthesis (56 and 57%), net photosynthesis (62 and 60%) and respiration (43 and 48%) of A. millepora and H. opuntia, respectively. In contrast to A. millepora, H. opuntia significantly increased chlorophyll content by 15% over the course of the experiment. No interactive effects of OA and low light intensity were found on any response variable for either organism. However, A. millepora exhibited additive effects of OA and low light, while H. opuntia was only affected by low light. Thus, this study suggests that negative effects of low light and OA are additive on corals, which may have implications for management of river discharge into coastal coral reefs. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2015) 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 2015-06-01.