Data

Primary productivity, pulse amplitude modulated fluorometry and nutrient drawdown data from the marginal ice zone: BROKE-WEST survey 30o-80oE, 2006

Australian Antarctic Data Centre
WESTWOOD, KAREN JILLIAN
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=info:doi10.4225/15/515B7978E65A0&rft.title=Primary productivity, pulse amplitude modulated fluorometry and nutrient drawdown data from the marginal ice zone: BROKE-WEST survey 30o-80oE, 2006&rft.identifier=10.4225/15/515B7978E65A0&rft.publisher=Australian Antarctic Data Centre&rft.description=This data set contains primary productivity, pulse amplitude modulated fluorometry, and nutrient drawdown numbers associated with the abstract presented below. 14C Primary Productivity Gross column-integrated primary productivity determined through measurement of NaH14CO3 uptake by phytoplankton (1 hour incubations). Primary productivity was modelled from photosynthesis v irradiance curves, chlorophyll profiles, photosynthetically active radiation, and vertical light attenuation. Data for these parameters are also shown. Nutrient Draw-down Data Seasonal depletion of oxidised inorganic nitrogen and silicate in the mixed layer, and production of oxygen. Data was calculated by the subtraction of mixed layer concentrations (uM) from values below the mixed layer. Pulse Amplitude Modulated Fluorometry Data Fv/Fm values determined using pulse amplitude modulated fluorometry (PAM). Samples were dark-adapted prior to measurement so that non-photochemical quenching was relaxed. Values provide an indication of cell health. Abstract Primary productivity was measured in the Indian Sector of the Southern Ocean (30 degrees to 80 degrees E) as part of a multi-disciplinary study during austral summer; Baseline Research on Oceanography, Krill and the Environment, West (BROKE-West Survey, 2006). Gross integrated (0-150 m) productivity rates within the marginal ice zone (MIZ) were significantly higher than within the open ocean, with averages of 2110.2 plus or minus 1347.1 and 595.0 plus or minus 283.0 mg C m-2 d-1, respectively. In the MIZ, high productivity was associated with shallow mixed layer depths and increased Pmax up to 5.158 mg C (mg chl a)-1 h-1. High Si:N drawdown ratios in the open ocean (4.1 plus or minus 1.5) compared to the MIZ (2.2 plus or minus 0.79) also suggested that iron limitation was important for the control of productivity. This was supported by higher Fv/Fm ratios in the MIZ (0.50 plus or minus 0.11 above 40 m) compared to the open ocean (0.36 plus or minus 0.08). As well, in the open ocean there were regions of elevated productivity associated with the seasonal pycnocline where iron availability was possibly increased. High silicate drawdown in the north-eastern section of the BROKE-West survey area suggested significant diatom growth and was linked to the presence of the southern Antarctic Circumpolar Current front (sACCF). However, low assimilation numbers (12.8 to 23.2 mg C mg chl a-1 d-1) and Fv/Fm ratios indicated that cells were senescent with initial growth occurring earlier in the season. In the western section of the survey area within the MIZ, high NO3 drawdown but relatively low silicate drawdown were associated with a Phaeocystis bloom. NO3 concentrations were strongly negatively correlated with column-integrated productivity and chlorophyll biomass which was expected given the requirement for this nutrient by all phytoplankton groups. Regardless, concentrations of both NO3 and silicate were above limiting levels within the entire BROKE-West survey area (N greater than 15.7 micro M, Si greater than 18.3 micro M) supporting the high nutrient low chlorophyll status of the Southern Ocean.&rft.creator=WESTWOOD, KAREN JILLIAN &rft.date=2009&rft.coverage=northlimit=-61.5; southlimit=-67.2; westlimit=30; eastLimit=80; projection=WGS84&rft.coverage=northlimit=-61.5; southlimit=-67.2; westlimit=30; eastLimit=80; projection=WGS84&rft_rights=This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/). Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=BROKE-West_primary_productivity when using these data.&rft_subject=biota&rft_subject=environment&rft_subject=oceans&rft_subject=CARBON&rft_subject=EARTH SCIENCE&rft_subject=OCEANS&rft_subject=OCEAN CHEMISTRY&rft_subject=NUTRIENTS&rft_subject=OCEAN MIXED LAYER&rft_subject=OCEAN TEMPERATURE&rft_subject=PHYTOPLANKTON&rft_subject=BIOSPHERE&rft_subject=AQUATIC ECOSYSTEMS&rft_subject=PLANKTON&rft_subject=PRIMARY PRODUCTION&rft_subject=ECOLOGICAL DYNAMICS&rft_subject=ECOSYSTEM FUNCTIONS&rft_subject=iron limitation&rft_subject=vertical mixing&rft_subject=marginal ice zone&rft_subject=NISKIN BOTTLES&rft_subject=SCINTILLATION COUNTERS&rft_subject=PAM > PORTABLE FLUORESCENCE ANALYZERS&rft_subject=SHIPS&rft_subject=R/V AA > R/V Aurora Australis&rft_subject=OCEAN > SOUTHERN OCEAN&rft_subject=CONTINENT > ANTARCTICA&rft_subject=GEOGRAPHIC REGION > POLAR&rft_place=Hobart&rft.type=dataset&rft.language=English Access the data
Cite Saved to MyRDA Save to MyRDA

Licence & Rights:

view details

This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/). Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=BROKE-West_primary_productivity when using these data.

Access:

Open view details

These data are publicly available from the provided URL.

Brief description

This data set contains primary productivity, pulse amplitude modulated fluorometry, and nutrient drawdown numbers associated with the abstract presented below.

14C Primary Productivity
Gross column-integrated primary productivity determined through measurement of NaH14CO3 uptake by phytoplankton (1 hour incubations). Primary productivity was modelled from photosynthesis v irradiance curves, chlorophyll profiles, photosynthetically active radiation, and vertical light attenuation. Data for these parameters are also shown.

Nutrient Draw-down Data
Seasonal depletion of oxidised inorganic nitrogen and silicate in the mixed layer, and production of oxygen. Data was calculated by the subtraction of mixed layer concentrations (uM) from values below the mixed layer.

Pulse Amplitude Modulated Fluorometry Data
Fv/Fm values determined using pulse amplitude modulated fluorometry (PAM). Samples were dark-adapted prior to measurement so that non-photochemical quenching was relaxed. Values provide an indication of cell health.


Abstract
Primary productivity was measured in the Indian Sector of the Southern Ocean (30 degrees to 80 degrees E) as part of a multi-disciplinary study during austral summer; Baseline Research on Oceanography, Krill and the Environment, West (BROKE-West Survey, 2006). Gross integrated (0-150 m) productivity rates within the marginal ice zone (MIZ) were significantly higher than within the open ocean, with averages of 2110.2 plus or minus 1347.1 and 595.0 plus or minus 283.0 mg C m-2 d-1, respectively. In the MIZ, high productivity was associated with shallow mixed layer depths and increased Pmax up to 5.158 mg C (mg chl a)-1 h-1. High Si:N drawdown ratios in the open ocean (4.1 plus or minus 1.5) compared to the MIZ (2.2 plus or minus 0.79) also suggested that iron limitation was important for the control of productivity. This was supported by higher Fv/Fm ratios in the MIZ (0.50 plus or minus 0.11 above 40 m) compared to the open ocean (0.36 plus or minus 0.08). As well, in the open ocean there were regions of elevated productivity associated with the seasonal pycnocline where iron availability was possibly increased. High silicate drawdown in the north-eastern section of the BROKE-West survey area suggested significant diatom growth and was linked to the presence of the southern Antarctic Circumpolar Current front (sACCF). However, low assimilation numbers (12.8 to 23.2 mg C mg chl a-1 d-1) and Fv/Fm ratios indicated that cells were senescent with initial growth occurring earlier in the season. In the western section of the survey area within the MIZ, high NO3 drawdown but relatively low silicate drawdown were associated with a Phaeocystis bloom. NO3 concentrations were strongly negatively correlated with column-integrated productivity and chlorophyll biomass which was expected given the requirement for this nutrient by all phytoplankton groups. Regardless, concentrations of both NO3 and silicate were above limiting levels within the entire BROKE-West survey area (N greater than 15.7 micro M, Si greater than 18.3 micro M) supporting the high nutrient low chlorophyll status of the Southern Ocean.

Issued: 2009-09-22

Data time period: 2006-01-19 to 2006-02-27

This dataset is part of a larger collection

Click to explore relationships graph
Help

Related Organisations

Related People

80,-61.5 80,-67.2 30,-67.2 30,-61.5 80,-61.5

55,-64.35

text: northlimit=-61.5; southlimit=-67.2; westlimit=30; eastLimit=80; projection=WGS84

Subjects
AQUATIC ECOSYSTEMS | BIOSPHERE | CARBON | CONTINENT > ANTARCTICA | EARTH SCIENCE | ECOLOGICAL DYNAMICS | ECOSYSTEM FUNCTIONS | GEOGRAPHIC REGION > POLAR | NISKIN BOTTLES | NUTRIENTS | OCEAN > SOUTHERN OCEAN | OCEAN CHEMISTRY | OCEAN MIXED LAYER | OCEAN TEMPERATURE | OCEANS | PAM > PORTABLE FLUORESCENCE ANALYZERS | PHYTOPLANKTON | PLANKTON | PRIMARY PRODUCTION | R/V AA > R/V Aurora Australis | SCINTILLATION COUNTERS | SHIPS | biota | environment | iron limitation | marginal ice zone | oceans | vertical mixing |

User Contributed Tags    

Login to tag this record with meaningful keywords to make it easier to discover

Other Information

AU-ANL:PEAU : http://nla.gov.au/nla.party-617536

Identifiers
Similar data you may be interested in: