Nutrient availability affects the response of the calcifying chlorophyte Halimeda opuntia (L.) J.V. Lamouroux to low pH, supplement to: Hofmann, Laurie C; Heiden, Jasmin; Bischof, Kai; Teichberg, Mirta (2013): Nutrient availability affects the response of the calcifying chlorophyte Halimeda opuntia (L.) J.V. Lamouroux to low pH. Planta, 239(1), 231-242

• Main Authors: Hofmann, Laurie C, Heiden, Jasmin, Bischof, Kai, Teichberg, Mirta
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2014
• Subjects: Benthos; Biomass/Abundance/Elemental composition; Calcification/Dissolution; Chlorophyta; Coast and continental shelf; Growth/Morphology; Halimeda opuntia; Laboratory experiment; Macroalgae; Macro-nutrients; Mesocosm or benthocosm; Not applicable; Other metabolic rates; Plantae; Primary production/Photosynthesis; Single species; Tropical; Species; Treatment; Calcification rate of calcium carbonate; Carbonic anhydrase, activity; Nitrate reductase activity; Carbon, organic, total; Carbon, inorganic, total; Maximal electron transport rate, relative; Carbon organic/inorganic ratio; Calcium carbonate; Nitrogen, total; Phosphorus; Nitrogen/Phosphorus ratio; Growth rate; Light saturation point; Initial slope of rapid light curve; Salinity; Temperature, water; pH; Alkalinity, total; Carbonate system computation flag; Carbon dioxide; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Aragonite saturation state; Calcite saturation state; Potentiometric; Potentiometric titration; Calculated using seacarb after Nisumaa et al. 2010; Biological Impacts of Ocean Acidification BIOACID; Ocean Acidification International Coordination Centre OA-ICC; Laurie; Hofmann; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.839344; https://doi.pangaea.de/10.1594/PANGAEA.839344

Atmospheric carbon dioxide emissions cause a decrease in the pH and aragonite saturation state of surface ocean water. As a result, calcifying organisms are expected to suffer under future ocean conditions, but their physiological responses may depend on their nutrient status. Because many coral reefs experience high inorganic nutrient loads or seasonal changes in nutrient availability, reef organisms in localized areas will have to cope with elevated carbon dioxide and changes in inorganic nutrients. Halimeda opuntia is a dominant calcifying primary producer on coral reefs that contributes to coral reef accretion. Therefore, we investigated the carbon and nutrient balance of H. opuntia exposed to elevated carbon dioxide and inorganic nutrients. We measured tissue nitrogen, phosphorus and carbon content as well as the activity of enzymes involved in inorganic carbon uptake and nitrogen assimilation (external carbonic anhydrase and nitrate reductase, respectively). Inorganic carbon content was lower in algae exposed to high CO2, but calcification rates were not significantly affected by CO2 or inorganic nutrients. Organic carbon was positively correlated to external carbonic anhydrase activity, while inorganic carbon showed the opposite correlation. Carbon dioxide had a significant effect on tissue nitrogen and organic carbon content, while inorganic nutrients affected tissue phosphorus and N:P ratios. Nitrate reductase activity was highest in algae grown under elevated CO2 and inorganic nutrient conditions and lowest when phosphate was limiting. In general, we found that enzymatic responses were strongly influenced by nutrient availability, indicating its important role in dictating the local responses of the calcifying primary producer H. opuntia to 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 2014-11-24.