Ocean acidification alleviates low-temperature effects on growth and photosynthesis of the red alga Neosiphonia harveyi (Rhodophyta), supplement to: Olischläger, Mark; Wiencke, Christian (2013): Ocean acidification alleviates low-temperature effects on growth and photosynthesis of the red alga Neosiphonia harveyi (Rhodophyta). Journal of Experimental Botany, 64(18), 5587-5597

• Main Authors: Olischläger, Mark, Wiencke, Christian
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2013
• Subjects: Benthos; Bottles or small containers/Aquaria <20 L; Coast and continental shelf; Growth/Morphology; Laboratory experiment; Macroalgae; Neosiphonia harveyi; North Atlantic; Plantae; Primary production/Photosynthesis; Rhodophyta; Single species; Temperature; Tropical; Species; Experiment; Figure; Treatment; Identification; Maximal electron transport rate, relative; Light saturation; Photosynthetic quantum efficiency; Effective quantum yield; Irradiance; Electron transport rate; Net photosynthesis rate, oxygen; pH; Time in hours; Inhibition of net photosynthesis; Mass; Incubation duration; Growth rate; Chlorophyll a; Ratio; Salinity; Salinity, standard deviation; Temperature, water; Temperature, water, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; pH, 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; Carbon dioxide; Carbon dioxide, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Potentiometric; Potentiometric titration; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. 2010; Biological Impacts of Ocean Acidification BIOACID; Ocean Acidification International Coordination Centre OA-ICC; Wiencke; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.834202; https://doi.pangaea.de/10.1594/PANGAEA.834202

This study aimed to examine interactive effects between ocean acidification and temperature on the photosynthetic and growth performance of Neosiphonia harveyi. N. harveyi was cultivated at 10 and 17.5 °C at present (~380 µatm), expected future (~800 µatm), and high (~1500 µatm) pCO2. Chlorophyll a fluorescence, net photosynthesis, and growth were measured. The state of the carbon-concentrating mechanism (CCM) was examined by pH-drift experiments (with algae cultivated at 10 °C only) using ethoxyzolamide, an inhibitor of external and internal carbonic anhydrases (exCA and intCA, respectively). Furthermore, the inhibitory effect of acetazolamide (an inhibitor of exCA) and Tris (an inhibitor of the acidification of the diffusive boundary layer) on net photosynthesis was measured at both temperatures. Temperature affected photosynthesis (in terms of photosynthetic efficiency, light saturation point, and net photosynthesis) and growth at present pCO2, but these effects decreased with increasing pCO2. The relevance of the CCM decreased at 10 °C. A pCO2 effect on the CCM could only be shown if intCA and exCA were inhibited. The experiments demonstrate for the first time interactions between ocean acidification and temperature on the performance of a non-calcifying macroalga and show that the effects of low temperature on photosynthesis can be alleviated by increasing pCO2. The findings indicate that the carbon acquisition mediated by exCA and acidification of the diffusive boundary layer decrease at low temperatures but are not affected by the cultivation level of pCO2, whereas the activity of intCA is affected by pCO2. Ecologically, the findings suggest that ocean acidification might affect the biogeographical distribution of N. harveyi. : 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 2014-07-22.