Empirical Evidence Reveals Seasonally Dependent Reduction in Nitrification in Coastal Sediments Subjected to Near Future Ocean Acidification


Research so far has provided little evidence that benthic biogeochemical cycling is affected by ocean acidification under realistic climate change scenarios. We measured nutrient exchange and sediment community oxygen consumption (SCOC) rates to estimate nitrification in natural coastal permeable and fine sandy sediments under pre-phytoplankton bloom and bloom conditions. Ocean acidification, as mimicked in the laboratory by a realistic pH decrease of 0.3, significantly reduced SCOC on average by 60% and benthic nitrification rates on average by 94% in both sediment types in February (pre-bloom period), but not in April (bloom period). No changes in macrofauna functional community (density, structural and functional diversity) were observed between ambient and acidified conditions, suggesting that changes in benthic biogeochemical cycling were predominantly mediated by changes in the activity of the microbial community during the short-term incubations (14 days), rather than by changes in engineering effects of bioturbating and bio-irrigating macrofauna. As benthic nitrification makes up the gross of ocean nitrification, a slowdown of this nitrogen cycling pathway in both permeable and fine sediments in winter, could therefore have global impacts on coupled nitrification-denitrification and hence eventually on pelagic nutrient availability.

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 2014-12-04.

DOI https://doi.org/10.1594/PANGAEA.840479
Related Identifier https://doi.org/10.1371/journal.pone.0108153.s002
Related Identifier https://doi.org/10.14284/1
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.840479
Creator Braeckman, Ulrike ORCID logo; Van Colen, Carl ORCID logo; Guilini, Katja ORCID logo; Van Gansbeke, D; Soetaert, Karline ORCID logo; Vincx, Magda; Vanaverbeke, Jan; Vopel, Kay
Publisher PANGAEA
Contributor Yang, Yan
Publication Year 2014
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Dataset
Format text/tab-separated-values
Size 3558 data points
Discipline Earth System Research
Spatial Coverage (2.620W, 51.159S, 2.808E, 51.433N)
Temporal Coverage Begin 2012-02-13T00:00:00Z
Temporal Coverage End 2012-04-18T00:00:00Z