title: Elevated CO2 induces a bloom of microphytobenthos within a shell gravel mesocosm.
abstract: The geological storage of carbon dioxide (CO2) is expected to be an important component of future global carbon emission mitigation, but there is a need to understand the impacts of a CO2 leak on the marine environment and to develop monitoring protocols for leakage detection. In the present study, sediment cores were exposed to CO2-acidified seawater at one of five pH levels (8.0, 7.5, 7.0, 6.5 and 6.0) for 10 weeks. A bloom of Spirulina sp. and diatoms appeared on sediment surface exposed to pH 7.0 and 7.5 seawater. Quantitative PCR measurements of the abundance of 16S rRNA also indicated an increase within the pH 7.0 and 7.5 treatments after 10 weeks incubation. More detailed analysis of the microbial communities from the pH 7.0, 7.5 and 8.0 treatments confirmed an increase in the relative abundance of Spirulina sp. and Navicula sp. sequences, with changes in the relative abundance of major archaeal and bacterial groups also detected within the pH 7.0 treatment. A decreased flux of silicate from the sediment at this pH was also detected. Monitoring blooms of microphytobenthos may prove useful as an indicator of CO2 leakage within coastal areas.
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK ktait@pml.ac.uk.
authors.forename: Karen
authors.initials: K
authors.lastname: Tait
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Beesley
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: Helen S
authors.initials: HS
authors.lastname: Findlay
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: C Louise
authors.initials: CL
authors.lastname: McNeill
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Widdicombe
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics; D001483:Base Sequence; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D017377:Diatoms / Q000254:growth & development*; D005068:Eutrophication; D055593:Geological Phenomena; D006863:Hydrogen-Ion Concentration; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D053545:Spirulina / Q000254:growth & development*
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide
keywords: 16S rRNA 454 pyrosequencing; CCS; microphytobenthos; nutrient fluxes; quantitative PCR; sediment