Seawater carbonate chemistry and proportion of different dissolution levels in live juvenile Limacina helicina antarctica from the natural environment and ship-board incubations

DOI

The carbonate chemistry of the surface ocean is rapidly changing with ocean acidification, a result of human activities. In the upper layers of the Southern Ocean, aragonite-a metastable form of calcium carbonate with rapid dissolution kinetics-may become undersaturated by 2050. Aragonite undersaturation is likely to affect aragonite-shelled organisms, which can dominate surface water communities in polar regions. Here we present analyses of specimens of the pteropod Limacina helicina antarctica that were extracted live from the Southern Ocean early in 2008. We sampled from the top 200 m of the water column, where aragonite saturation levels were around 1, as upwelled deep water is mixed with surface water containing anthropogenic CO2. Comparing the shell structure with samples from aragonite-supersaturated regions elsewhere under a scanning electron microscope, we found severe levels of shell dissolution in the undersaturated region alone. According to laboratory incubations of intact samples with a range of aragonite saturation levels, eight days of incubation in aragonite saturation levels of 0.94-1.12 produces equivalent levels of dissolution. As deep-water upwelling and CO2 absorption by surface waters is likely to increase as a result of human activities, we conclude that upper ocean regions where aragonite-shelled organisms are affected by dissolution are likely to expand.

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 2014-05-29.

Supplement to: Bednaršek, Nina; Tarling, Geraint A; Bakker, Dorothee C E; Fielding, Sophie; Jones, Elizabeth M; Venables, H J; Ward, Peter; Kuzirian, Alan; Lézé, Bertrand; Feely, Richard A; Murphy, Eugene J (2012): Extensive dissolution of live pteropods in the Southern Ocean. Nature Geoscience, 5(12), 881-885

Identifier
DOI https://doi.org/10.1594/PANGAEA.833075
Related Identifier https://doi.org/10.1038/ngeo1635
Related Identifier https://cran.r-project.org/package=seacarb
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.833075
Provenance
Creator Bednaršek, Nina; Tarling, Geraint A; Bakker, Dorothee C E ORCID logo; Fielding, Sophie; Jones, Elizabeth M ORCID logo; Venables, H J; Ward, Peter; Kuzirian, Alan; Lézé, Bertrand; Feely, Richard A; Murphy, Eugene J
Publisher PANGAEA
Contributor Yang, Yan
Publication Year 2012
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 904 data points
Discipline Earth System Research
Spatial Coverage (-48.000W, -60.000S, -34.000E, -50.000N)
Temporal Coverage Begin 2008-02-01T00:00:00Z
Temporal Coverage End 2008-02-28T00:00:00Z