Seawater carbonate chemistry and growth, net photosynthesis, pigments, stable isotopes of macroalgae Lomentaria australis and Craspedocarpus ramentaceus

• Main Authors: van der Loos, Luna M, Schmid, Matthias, Leal, Pablo P, McGraw, Christina M, Britton, Damon, Revill, Andrew T, Virtue, Patti, Nichols, Peter D, Hurd, Catriona L
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2019
• Subjects: Benthos; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Coast and continental shelf; Craspedocarpus ramentaceus; Growth/Morphology; Laboratory experiment; Lomentaria australis; Macroalgae; Other studied parameter or process; Plantae; Primary production/Photosynthesis; Rhodophyta; Single species; South Pacific; Temperate; Type; Species; Registration number of species; Uniform resource locator/link to reference; Sample code/label; Treatment; Name; Fatty acids; Length; Growth; Dry mass; Lipids; Hydrocarbons; Triacylglycerols; Fatty acids, free; Sterols; Lipids, polar; Trans fatty acids of total fatty acids; Saturated fatty acids of total fatty acids; Monounsaturated fatty acids of total fatty acids; Polyunsaturated fatty acids of total fatty acids; Net photosynthesis rate, oxygen; Chlorophyll a; Phycobiliproteins; Phycocyanin; Phycoerythrin; Change; Growth rate; Temperature, water; Salinity; pH; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity 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; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.922244; https://doi.pangaea.de/10.1594/PANGAEA.922244

Increased plant biomass is observed in terrestrial systems due to rising levels of atmospheric CO2, but responses of marine macroalgae to CO2 enrichment are unclear. The 200% increase in CO2 by 2100 is predicted to enhance the productivity of fleshy macroalgae that acquire inorganic carbon solely as CO2 (non‐carbon dioxide‐concentrating mechanism [CCM] species-i.e., species without a carbon dioxide‐concentrating mechanism), whereas those that additionally uptake bicarbonate (CCM species) are predicted to respond neutrally or positively depending on their affinity for bicarbonate. Previous studies, however, show that fleshy macroalgae exhibit a broad variety of responses to CO2 enrichment and the underlying mechanisms are largely unknown. This physiological study compared the responses of a CCM species (Lomentaria australis) with a non‐CCM species (Craspedocarpus ramentaceus) to CO2 enrichment with regards to growth, net photosynthesis, and biochemistry. Contrary to expectations, there was no enrichment effect for the non‐CCM species, whereas the CCM species had a twofold greater growth rate, likely driven by a downregulation of the energetically costly CCM(s). This saved energy was invested into new growth rather than storage lipids and fatty acids. In addition, we conducted a comprehensive literature synthesis to examine the extent to which the growth and photosynthetic responses of fleshy macroalgae to elevated CO2 are related to their carbon acquisition strategies. Findings highlight that the responses of macroalgae to CO2 enrichment cannot be inferred solely from their carbon uptake strategy, and targeted physiological experiments on a wider range of species are needed to better predict responses of macroalgae to future oceanic change. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2019) 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 2020-07-07.