Seawater carbonate chemistry and physiological performance of the rhodolith Sporolithon sp.

• Main Authors: Narvarte, Bienson Ceasar V, Nelson, Wendy A, Roleda, Michael Y
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2020
• Subjects: Benthos; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Calcification/Dissolution; Coast and continental shelf; Growth/Morphology; Laboratory experiment; Macroalgae; North Pacific; Plantae; Rhodophyta; Single species; Sporolithon sp.; Tropical; Type; Species; Treatment; Growth; Growth, relative, standard error; Calcification rate of calcium carbonate; Calcification rate, standard error; Inorganic matter; Inorganic matter, standard error; Skeleton; Skeleton, standard error; Organic matter; Organic matter, standard error; Chlorophyll a; Chlorophyll a, standard error; Chlorophyll d; Chlorophyll d, standard error; Phycocyanin; Phycocyanin, standard error; Allophycocyanin; Allophycocyanin, standard error; Phycoerythrin; Phycoerythrin, standard error; Ammonium uptake rate; Ammonium uptake rate, standard error; Nitrite uptake rate; Nitrite uptake rate, standard error; Nitrate uptake rate; Nitrate uptake rate, standard error; Phosphate uptake rate; Phosphate uptake rate, standard error; Carbon; Carbon, standard error; Nitrogen; Nitrogen, standard error; Phosphorus; Phosphorus, standard error; Carbon/Nitrogen ratio; Carbon/Nitrogen ratio, standard error; Carbon/Phosphorus ratio; Carbon/Phosphorus ratio, standard error; Nitrogen/Phosphorus ratio; Nitrogen/Phosphorus ratio, standard error; pH; pH, standard error; Carbon dioxide; Carbon dioxide, standard error; Bicarbonate ion; Bicarbonate ion, standard error; Carbonate ion; Carbonate ion, standard error; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, 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; Calcite saturation state; Calcite saturation state, standard error; Alkalinity, total; Alkalinity, total, standard error; Salinity; Salinity, standard error; Temperature, water; Temperature, water, standard error; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Experiment; Potentiometric; Calculated using CO2SYS; Potentiometric titration; 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.924085; https://doi.pangaea.de/10.1594/PANGAEA.924085

Fish farming in coastal areas has become an important source of food to support the world's increasing population. However, intensive and unregulated mariculture activities have contributed to changing seawater carbonate chemistry through the production of high levels of respiratory CO2. This additional CO2, i.e. in addition to atmospheric inputs, intensifies the effects of global ocean acidification resulting in localized extreme low pH levels. Marine calcifying macroalgae are susceptible to such changes due to their CaCO3 skeleton. Their physiological response to CO2-driven acidification is dependent on their carbon physiology. In this study, we used the pH drift experiment to determine the capability of 9 calcifying macroalgae to use one or more inorganic carbon (Ci) species. From the 9 species, we selected the rhodolith Sporolithon sp. as a model organism to investigate the long-term effects of extreme low pH on the physiology and biochemistry of calcifying macroalgae. Samples were incubated under two pH treatments (pH 7.9 = ambient and pH 7.5 = extreme acidification) in a temperature-controlled (26 ± 0.02 °C) room provided with saturating light intensity (98.3 ± 2.50 μmol photons/m**2/s). After the experimental treatment period (40 d), growth rate, calcification rate, nutrient uptake rate, organic content, skeletal CO3-2, pigments, and tissue C, N and P of Sporolithon samples were compared. The pH drift experiment revealed species-specific Ci use mechanisms, even between congenerics, among tropical calcifying macroalgae. Furthermore, long-term extreme low pH significantly reduced the growth rate, calcification rate and skeletal CO3-2 content by 79%, 66% and 18%, respectively. On the other hand, nutrient uptake rates, organic matter, pigments and tissue C, N and P were not affected by the low pH treatments. Our results suggest that the rhodolith Sporolithon sp. is susceptible to the negative effects of extreme low pH resulting from intensive mariculture-driven coastal acidification. : 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 2020-10-20.