Sub-Antarctic zone mooring study of interannual variability in particulate carbon export - Phytoplankton Data

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Citation_Information:
Originator: Unknown
Publication_Date: Unknown
Title: Sub-Antarctic zone mooring study of interannual variability in particulate carbon export - Phytoplankton Data
Description:
Abstract:
Papers arising from phytoplankton experiments associated with the SAZ (Subantarctic Zone) project. This work was complete as part of ASAC (AAS) project 1156. Taken from the abstracts of the referenced papers: Subantarctic Southern Ocean surface waters in the austral summer and autumn are characterised by high concentrations of nitrate and phosphate but low concentrations of dissolved iron (Fe, ~0.05 nM) and silicic acid (Si, less than 1 micro M). During the Subantarctic Zone AU9706 cruise in March 1998 we investigated the relative importance of Fe and Si in controlling phytoplankton growth and species composition at a station within the subantarctic water mass (46.8 degrees S, 142 degrees E) using shipboard bottle incubation experiments. Treatments included unamended controls; 1.9 nM added iron (+Fe); 9 micro M added silicic acid (+Si); and 1.9 nM added iron plus 9 micro M added silicic acid (+Fe+Si). We followed a detailed set of biological and biogeochemical parameters over 8 days. Fe added alone clearly increased community growth rates and nitrate drawdown and altered algal community composition relative to control treatments. Surprisingly, small, lightly silicified pennate diatoms grew when Fe was added either with or without Si, despite the extremely low ambient silicic acid concentrations. Pigment analyses suggest that lightly silicified chrysophytes (type 4 haptophytes) may have preferentially responded to Si added either with or without Fe. However, for many of the parameters measured the +Fe+Si treatments showed large increases relative to both the +Fe and +Si treatments. Our results suggest that iron is the proximate limiting nutrient for chlorophyll production, photosynthetic efficiency, nitrate drawdown, and diatom growth, but that Si also exerts considerable control over algal growth response, suggesting that both Fe and Si play important roles in structuring the subantarctic phytoplankton community. The influence of irradiance and iron (Fe) supply on phytoplankton processes was investigated, north (47 degrees S, 142 degrees E) and south (54 degrees S, 142 degrees E) of the subantarctic Front in austral autumn (March 1998). At both sites, resident cells exhibited nutrient stress. Shipboard perturbation experiments examined two light (mean in situ and elevated) and two Fe (nominally 0.5 and 3 nM) treatments under silicic acid-replete conditions. Mean in situ light levels (derived from incident irradiances, mixed layer depths (MLDs), wind stress, and a published vertical mixing model) differed at the two sites, 25% of incident irradiance I0 at 47 degrees S and 9% I0 at 54 degrees S because of MLDs of 40 (47S) and 90 m (54S), when these stations were occupied. The greater MLD at 54S is reflected by tenfold higher cellular chlorophyll a levels in the resident phytoplankton. In the 47S experiment, chlorophyll a levels increased to greater than 1 micro gram per litre only in the high-Fe treatments, regardless of irradiance levels, suggesting Fe limitation. This trend was also noted for cell abundances, silica production, and carbon fixation rates. In contrast, in the 54S experiment there were increases in chlorophyll a (to greater than 2 micro grams per litre), cell abundances, silica production, and carbon fixation only in the high-light treatments to which Fe had been added, suggesting that Fe and irradiance limit algal growth rates. Irradiance by altering algal Fe quotas is a key determinant of algal growth rate at 54S (when silicic acid levels are nonlimiting); however, because of the integral nature of Fe/light colimitation and the restricted nature of the current data set, it was not possible to ascertain the relative contributions of Fe and irradiance to the control of phytoplankton growth. On the basis of a climatology of summer mean MLD for subantarctic (SA) waters south of Australia the 47 and 54S sites appear to represent minimum and maximum MLDs, where Fe and Fe/ irradiance, respectively, may limit/colimit algal growth. The implications for changes in the factors limiting algal growth with season in SA waters are discussed.
Purpose:
Not Available
Supplemental_Information:
REFERENCE: Boyd, P. W., A. C. Crossley, G. R. DiTullio, F. B. Griffiths, D. A. Hutchins, B. Queguiner, P. N. Sedwick, and T. W. Trull 2001 Control of phytoplankton growth by iron supply and irradiance in the subantarctic Southern Ocean: Experimental results from the SAZ Project JOURNAL OF GEOPHYSICAL RESEARCH 106 C12 31,573-31,583 doi:10.1029/2000JC000348
Supplemental_Information:
REFERENCE: Hutchins, D. A., P. N. Sedwick, G. R. DiTullio, P. W. Boyd, B. Queguiner, F. B. Griffiths, and C. Crossley 2001 Control of phytoplankton growth by iron and silicic acid availability in the subantarctic Southern Ocean: Experimental results from the SAZ Project JOURNAL OF GEOPHYSICAL RESEARCH 106 C12 31,559-31,572 doi:10.1029/2000JC000333
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19980301
Ending_Date: 19980331
Currentness_Reference:Unknown
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Description_of_Geographic_Extent:
Bounding_Coordinates:
West_Bounding_Coordinate: 142.0
East_Bounding_Coordinate: 142.0
North_Bounding_Coordinate: -47.0
South_Bounding_Coordinate: -54.0
Keywords:
Theme:
Theme_Keyword_Thesaurus: GCMD SCIENCE PARAMETERS
Theme_Keyword_Thesaurus: GCMD PLATFORM
Theme_Keyword_Thesaurus: ANCILLARY KEYWORDS
Theme_Keyword_Thesaurus: ISO TOPIC CATEGORY
Theme_Keyword_Thesaurus: DATA SET LANGUAGE
Theme_Keyword: EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NUTRIENTS
Theme_Keyword: EARTH SCIENCE > OCEANS > OCEAN CIRCULATION > WATER MASSES
Theme_Keyword: EARTH SCIENCE > OCEANS > OCEAN OPTICS > IRRADIANCE
Theme_Keyword: EARTH SCIENCE > BIOSPHERE > AQUATIC ECOSYSTEMS > PLANKTON > PHYTOPLANKTON
Theme_Keyword: EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > PROTISTS > PLANKTON > PHYTOPLANKTON
Theme_Keyword: LABORATORY
Theme_Keyword: R/V AA > R/V AURORA AUSTRALIS
Theme_Keyword: Phytoplankton
Theme_Keyword: Iron
Theme_Keyword: Saz
Theme_Keyword: Growth
Theme_Keyword: Silicic Acid
Theme_Keyword: BIOTA
Theme_Keyword: OCEANS
Theme_Keyword: ENGLISH
Place:
Place_Keyword_Thesaurus: GCMD
Place_Keyword: OCEAN > SOUTHERN OCEAN
Place_Keyword: GEOGRAPHIC REGION > POLAR
Access_Constraints: PDF copies of the referenced publications are available for download from the provided URL for AAD staff only.
Use_Constraints:
This data set conforms to the PICCCBY Attribution License (http://creativecommons.org/licenses/by/3.0/). Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1156_Phytoplankton when using these data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: THOMAS WILLIAM TRULL
Contact_Position: INVESTIGATOR
Contact_Position: TECHNICAL CONTACT
Contact_Address:
Address_Type: Mailing and Physical Address
Address: GPO BOX 252-80
Address: Antarctic CRC University of Tasmania
City: Hobart
State_or_Province: Tasmania
Postal_Code: 7001
Country: Australia
Contact_Voice_Telephone: +61 3 6226 2988
Contact_Facsimile_Telephone: +61 3 6226 2973
Contact_Electronic_Mail_Address: tom.trull@utas.edu.au
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Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
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Logical_Consistency_Report:
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Completeness_Report:
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Lineage:
Process_Step:
Process_Description:
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Process_Date: Unknown
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Spatial_Reference_Information:
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: AU/AADC > Australian Antarctic Data Centre, Australia
Contact_Person: DATA OFFICER AADC
Contact_Position: DATA CENTER CONTACT
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Australian Antarctic Division
Address: 203 Channel Highway
City: Kingston
State_or_Province: Tasmania
Postal_Code: 7050
Country: Australia
Contact_Voice_Telephone: +61 3 6232 3244
Contact_Facsimile_Telephone: +61 3 6232 3351
Contact_Electronic_Mail_Address: metadata@aad.gov.au
Resource_Description: ASAC_1156_Phytoplankton
Distribution_Liability:
Not Available
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: pdf
Transfer_Size: 3.6 MB
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://data.aad.gov.au
Access_Instructions:
DATA CENTER URL
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
https://secure3.aad.gov.au/proms/public/projects/r...
Access_Instructions:
Public information for ASAC project 1156
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://data.aad.gov.au/aadc/portal/download_file.c...
Access_Instructions:
Download point for the referenced publications
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
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http://data.aad.gov.au/aadc/metadata/citation.cfm?...
Access_Instructions:
Citation reference for this metadata record and dataset
Fees: Free
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Metadata_Reference_Information:
Metadata_Date: 20120308
Metadata_Review_Date: 20140828
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: DAVE J. CONNELL
Contact_Position: DIF AUTHOR
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Australian Antarctic Division
Address: 203 Channel Highway
City: Kingston
State_or_Province: Tasmania
Postal_Code: 7050
Country: Australia
Contact_Voice_Telephone: +61 3 6232 3244
Contact_Facsimile_Telephone: +61 3 6232 3351
Contact_Electronic_Mail_Address: dave.connell@aad.gov.au
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
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