EPOCA Svalbard 2009 benthic experiment: Serripes study, 2009, supplement to: Tait, Karen; Laverock, Bonnie; Widdicombe, Stephen (2013): Response of an Arctic Sediment Nitrogen Cycling Community to Increased CO2. Estuaries and Coasts, 37(3), 724-735

• Main Authors: Tait, Karen, Laverock, Bonnie, Widdicombe, Stephen
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2014
• Subjects: Arctic; Benthos; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Entire community; Gene expression incl. proteomics; Laboratory experiment; Polar; Soft-bottom community; Identification; Experimental treatment; amoA gene, copy number in sediment; Gene transcripts in sediments; Sample ID; Presence/absence; Salinity; Temperature, water; Temperature, water, standard deviation; pH; pH, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Calcite saturation state; Calcite saturation state, 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; Potentiometric; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. 2010; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Svalbard; Tait; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.769754; https://doi.pangaea.de/10.1594/PANGAEA.769754

Ocean acidification influences sediment/water nitrogen fluxes, possibly by impacting on the microbial process of ammonia oxidation. To investigate this further, undisturbed sediment cores collected from Ny Alesund harbour (Svalbard) were incubated with seawater adjusted to CO2 concentrations of 380, 540, 760, 1,120 and 3,000 µatm. DNA and RNA were extracted from the sediment surface after 14 days' exposure and the abundance of bacterial and archaeal ammonia oxidising (amoA) genes and transcripts quantified using quantitative polymerase chain reaction. While there was no change to the abundance of bacterial amoA genes, an increase to 760 µatm pCO2 reduced the abundance of bacterial amoA transcripts by 65 %, and this was accompanied by a shift in the composition of the active community. In contrast, archaeal amoA gene and transcript abundance both doubled at 3,000 µatm, with an increase in species richness also apparent. This suggests that ammonia oxidising bacteria and archaea in marine sediments have different pH optima, and the impact of elevated CO2 on N cycling may be dependent on the relative abundances of these two major microbial groups. Further evidence of a shift in the balance of key N cycling groups was also evident: the abundance of nirS-type denitrifier transcripts decreased alongside bacterial amoA transcripts, indicating that NO3 ? produced by bacterial nitrification fuelled denitrification. An increase in the abundance of Planctomycete-specific 16S rRNA, the vast majority of which grouped with known anammox bacteria, was also apparent at 3,000 µatm pCO2. This could indicate a possible shift from coupled nitrification-denitrification to anammox activity at elevated CO2. : 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 2014-07-07.