Experiment: Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification, supplement to: Stumpp, Meike; Hu, Marian Y; Melzner, Frank; Gutowska, Magdalena A; Dorey, Narimane; Himmerkus, Nina; Holtmann, Wiebke C; Dupont, Sam; Thorndyke, Mike; Bleich, Markus (2012): Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification. Proceedings of the National Academy of Sciences, 109(44), 18192-18197

• Main Authors: Stumpp, Meike, Hu, Marian Y, Melzner, Frank, Gutowska, Magdalena A, Dorey, Narimane, Himmerkus, Nina, Holtmann, Wiebke C, Dupont, Sam, Thorndyke, Mike, Bleich, Markus
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2012
• Subjects: Acid-base regulation; Animalia; Bottles or small containers/Aquaria <20 L; Coast and continental shelf; Echinodermata; Laboratory experiment; North Atlantic; Pelagos; Single species; Strongylocentrotus droebachiensis; Temperate; Zooplankton; Species; Figure; Treatment; Replicate; pH; pH, extracellular; Partial pressure of carbon dioxide water at sea surface temperature wet air; Molecular mass; Time in minutes; Fluorescence; Fluorescence, standard deviation; Time in seconds; Ratio; pH, intracellular; Recovery; Slope inclination; Temperature, water; Temperature, water, standard deviation; Salinity; Salinity, standard deviation; pH, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Partial pressure of carbon dioxide, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Alkalinity, total; Calculated using seacarb after Nisumaa et al. 2010; Biological Impacts of Ocean Acidification BIOACID; Ocean Acidification International Coordination Centre OA-ICC; Marian; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.833111; https://doi.pangaea.de/10.1594/PANGAEA.833111

Calcifying echinoid larvae respond to changes in seawater carbonate chemistry with reduced growth and developmental delay. To date, no information exists on how ocean acidification acts on pH homeostasis in echinoderm larvae. Understanding acid-base regulatory capacities is important because intracellular formation and maintenance of the calcium carbonate skeleton is dependent on pH homeostasis. Using H(+)-selective microelectrodes and the pH-sensitive fluorescent dye BCECF, we conducted in vivo measurements of extracellular and intracellular pH (pH(e) and pH(i)) in echinoderm larvae. We exposed pluteus larvae to a range of seawater CO(2) conditions and demonstrated that the extracellular compartment surrounding the calcifying primary mesenchyme cells (PMCs) conforms to the surrounding seawater with respect to pH during exposure to elevated seawater pCO(2). Using FITC dextran conjugates, we demonstrate that sea urchin larvae have a leaky integument. PMCs and spicules are therefore directly exposed to strong changes in pH(e) whenever seawater pH changes. However, measurements of pH(i) demonstrated that PMCs are able to fully compensate an induced intracellular acidosis. This was highly dependent on Na(+) and HCO(3)(-), suggesting a bicarbonate buffer mechanism involving secondary active Na(+)-dependent membrane transport proteins. We suggest that, under ocean acidification, maintained pH(i) enables calcification to proceed despite decreased pH(e). However, this probably causes enhanced costs. Increased costs for calcification or cellular homeostasis can be one of the main factors leading to modifications in energy partitioning, which then impacts growth and, ultimately, results in increased mortality of echinoid larvae during the pelagic life stage. : 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 2014-05-28.