Antarctic diatom silicification diminishes under ocean acidification

• Other Authors: AADC (originator), AU/AADC > Australian Antarctic Data Centre, Australia (resourceProvider)
• Format: Dataset
• Language: unknown
• Published: Australian Ocean Data Network
• Subjects: biota; environment; oceans; DIATOMS; EARTH SCIENCE; BIOLOGICAL CLASSIFICATION; PLANTS; MICROALGAE; SILICATE; OCEAN CHEMISTRY; CARBON CYCLE/CARBON BUDGET MODELS; EARTH SCIENCE SERVICES; MODELS; SILICIFICATION; CARBON CYCLING; OCEAN ACIDIFICATION; MESOCOSM; MINICOSM; SPECTROPHOTOMETERS; PAM > PORTABLE FLUORESCENCE ANALYZERS; FLUOROMETERS; FLUORESCENCE MICROSCOPY; FIELD INVESTIGATION; FIELD SURVEYS; LABORATORY; AMD/AU; AMD; CEOS; GEOGRAPHIC REGION > POLAR; CONTINENT > ANTARCTICA > DAVIS STATION; OCEAN > SOUTHERN OCEAN > PRYDZ BAY; Antarctic; Davis Station; Davis-Station; East Antarctica; Prydz Bay; Southern Ocean; Stella; Antarc*; Antarctica; Ocean acidification
• Online Access: https://researchdata.ands.org.au/antarctic-diatom-silicification-ocean-acidification/1361086; https://data.aad.gov.au/metadata/records/AAS_4026_Silicification_CO2; https://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=AAS_4026_Silicification_CO2; https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=AAS_4026; https://data.aad.gov.au/eds/4840/download

No problems were encountered with data collection. The six level fCO2 gradient approach meant that our data could be analysed using a regression model, allowing us to identify functional relationships between our fCO2 treatment and our response variables. Gradient designs are more effective at uncovering underlying responses patterns to environmental drivers, improving interpolation potential and generally deliver more useful quantitative information for models. This data set was collected during an ocean acidification mesocosm experiment performed at Davis Station, Antarctica during the 2014/15 summer season. It includes: - description of methods for all data collection and analyses. - diatom cell volume - bulk silicification - species specific silicification via fluorescence microscopy - bulk community Fv/Fm on day 12 - single-cell PAM fluorometry data (maximum quantum yield of PSII: Fv/Fm) A natural community of Antarctic marine microbes from Prydz Bay, East Antarctica were exposed to a range of CO2 concentrations in 650 L minicosms to simulate possible future ocean conditions up to the year ~2200. Diatom silica precipitation rates were examined at CO2 concentrations between 343 to 1641 micro atm, measuring both the total diatom community response and that of individual species, to determine whether ocean acidification may influence future diatom ballast and therefore alter carbon and silica fluxes in the Southern Ocean. Described and analysed in: Antarctic diatom silicification diminishes under ocean acidification (submitted for review) Methods described in: Antarctic diatom silicification diminishes under ocean acidification (submitted for review) Location: Prydz bay, Davis Station, Antarctica (68 degrees 35'S, 77 degrees 58' E) Date: Summer 2014/2015 Worksheet descriptions: Bulk silicification - raw data Measured total and incorporated biogenic silica using spectrophotometer for all tanks on day 12 after 24 h incubation with PDMPO - raw data Bulk Fv/Fm - dark-adapted maximum quantum efficiency of PSII (Fv/Fm) on whole community - raw data Measured Fv/Fm of individual cells from 3 mesocosm tanks. Single-cell silicificiation, Fluorescence microscopy - raw data Measured autofluorescence and PDMPO fluorescence of individual diatoms from 6 mesocosm tanks Single-cell PAM, dark-adapted maximum quantum efficiency of PSII (Fv/Fm) - raw data Measured Fv/Fm of individual cells from 3 mesocosm tanks. Cell volume Calculated cell volume (um3) of 7 species from minicosm tanks 1 and 6 - raw data Abbreviations: Fv/Fm Maximum quantum yield of PSII PDMPO 2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)methoxy)phenyl)oxazole Tant Thalassiosira antarctica DiscLg Large Discoid centric diatoms Stella Stellarima microtrias Chaeto Chaetoceros spp. Prob Proboscia truncata Pseu Pseudonitzschia turgiduloides FragLg Fragilariopsis cylindrus / curta Centric Large Discoid centric diatoms LargeThalassiosira Large Discoid centric diatoms Based on the results of a previous study, a natural community of Antarctic marine microbes from Prydz Bay, East Antarctica were exposed to a range of CO2 concentrations in 650 L mesocosms to simulate possible future ocean conditions up to the year ∼2200. Diatom silica precipitation rates were examined at CO2 concentrations between 343 to 1641 micro atm, measuring both the total diatom community response and that of individual species, to determine whether ocean acidification may influence future diatom ballast and therefore alter carbon and silica fluxes in the Southern Ocean.