Seawater carbonate chemistry and bioerosion of croal reef

DOI

Ocean acidification (OA), the gradual decline in ocean pH and [CO3 ] 2- caused by rising levels of atmospheric CO2, poses a significant threat to coral reef ecosystems, depressing rates of calcium carbonate (CaCO3) production, and enhancing rates of bioerosion and dissolution. As ocean pH and [CO3] 2- decline globally, there is increasing emphasis on managing local stressors that can exacerbate the vulnerability of coral reefs to the effects of OA. We show that sustained, nutrient rich, lower pH submarine groundwater discharging onto nearshore coral reefs off west Maui lowers the pH of seawater and exposes corals to nitrate concentrations 50 times higher than ambient. Rates of coral calcification are substantially decreased, and rates of bioerosion are orders of magnitude higher than those observed in coral cores collected in the Pacific under equivalent low pH conditions but living in oligotrophic waters. Heavier coral nitrogen isotope (delta15N) values pinpoint not only site-specific eutrophication, but also a sewage nitrogen source enriched in 15N. Our results show that eutrophication of reef seawater by land-based sources of pollution can magnify the effects of OA through nutrient driven-bioerosion. These conditions could contribute to the collapse of coastal coral reef ecosystems sooner than current projections predict based only on ocean 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 2020-10-14.

Identifier
DOI https://doi.org/10.1594/PANGAEA.923983
Related Identifier https://doi.org/10.1002/2017JC013264
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.923983
Provenance
Creator Prouty, Nancy G ORCID logo; Cohen, Anne L; Yates, Kimberly Kaye; Storlazzi, Curt D ORCID logo; Swarzenski, Peter W ORCID logo; White, Lisa D
Publisher PANGAEA
Contributor Yang, Yan
Publication Year 2017
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Dataset
Format text/tab-separated-values
Size 191 data points
Discipline Earth System Research
Spatial Coverage (-156.231W, 20.312S, -156.231E, 20.315N)
Temporal Coverage Begin 2013-07-01T00:00:00Z
Temporal Coverage End 2013-07-31T00:00:00Z