Nella Dan: SIBEX II Cruise Phytoplankton Data
This voyage is one of six which studied the abundance and distribution of both phytoplankton and Euphausia superba. They provided a good coverage of the area at varying season times and conditions. Data collection: Seven north-south transects were made between 58 degrees and 93 degrees east, with wa...
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Australian Ocean Data Network
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| Online Access: | https://researchdata.ands.org.au/nella-dan-sibex-cruise-phytoplankton/685380 https://data.aad.gov.au/metadata/records/SIBEX_II_phyto https://data.aad.gov.au/eds/1243/download https://data.aad.gov.au/eds/1834/download https://data.aad.gov.au/eds/1996/download https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=40 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=SIBEX_II_phyto |
| Summary: | This voyage is one of six which studied the abundance and distribution of both phytoplankton and Euphausia superba. They provided a good coverage of the area at varying season times and conditions. Data collection: Seven north-south transects were made between 58 degrees and 93 degrees east, with water samples collected at intervals of 5 degrees longitude. A General Oceanics rosette sampler equipped with twelve 5L Niskin botles was used for water collection in the top 200m of the water column. Standard depths for pigment analysis were used; 0, 10, 25, 35, 50, 75, 100, 200m. Temperature and salinity in the vertical profile were also measured, using a Neil Brown Mark 3 CTD. Ship-board processing: The water samples were analysed for oxygen, salinity, nutrients, and phytoplankton species. The remaining 2L to 4L of the water sample were filtered under a slight vacuum (approx. 0.5 atm.) using Whatman GF/F filters (0.7 micro-metre nominal pore size, 47mm diameter), and the filters were then immediately frozen in liquid nitrogen. Post-ship processing: The frozen filter was broken into 5mm diameter pieces, and sonicated in 4mL methanol using a Braun Labsonic 1510 sonicator equipped with a 4mm diameer needle probe (30 seconds at 50W). It was then filtered using a simple centrifugal system, described in Wright, S. and Shearer, J. (1984) Rapid extraction and high-performance liquid chromatography of chlorophylls and cartenoids from marine plankton. Journal of Chromatography 294:281-295. The filter debris was washed with 0.5mL methanol and recentrifuged. The combined extract was filtered through a Millex-HV filter unit (0.5 micro-metre pore size, Millipore Corp.). High performance liquid chromatography (HPLC) was used for pigment analysis. A 200 micro-litre sample of the extract was injected directly into a Waters Associates liquid chromatograph. Two RCM-100 radial compression modules were used in series. The pigments were eluted using a linear gradient from 90:10 acetonitrile:water to 100% ethyl acetate over 20 minutes at 2mL/min. They were detected using a Waters 440 absorbance detector and integrated using a Waters Data Module. Small peak heights were measured manually and converted to pigment abundance using individual calibration curves, as the Data Module was found to be inaccurate when the signal-to-noise ratio was low. Absorption spectra were taken using a Hewlett-Packard 8450A spectrophotometer. Data are logically consistent, as oceanographic data (CTD measurements) were also obtained at the same sampling sites as the phytoplankton water collection sites. Large variations were found in the vertical distribution of the marker pigments along each north-south transect. In the major pigments, this represented patchiness in the distribution of phytoplankton in the water column, as the accuracy of the HPLC technique is within 5%. In minor pigments, experimental errors would have been more significant, and would have been superimposed on this patchiness. These data were manually typed in from ANARE Research Notes 58 by AADC staff. It is possible that some typing errors occurred. Several inconsitencies in the printed data were also discovered. This dataset contains results from the Second International BIOMASS Experiment II (SIBEX II) cruise of the Nella Dan, taken in January 1985. This cruise was the fourth cruise in a series of six. Phytoplankton samples were taken off Antarctica in the Australian sector (Mawson to Davis region) and Prydz Bay in January 1985. Taxonomic identity, distribution and abundance data were obtained, together with an extensive range of pigment analysis, using high performance liquid chromatography (HPLC). Over 60 pigments were analysed (only the major ones are listed here). The major phytoplankton investigated were diatoms, dinoflagellates and flagellates. This dataset is a subset of the full cruise. An excel spreadsheet containing the full pigment analysis obtained from the cruise is available for download from the URL given below. The spreadsheet is a digital version of the data presented in ANARE Research Notes 58, which was a report written based on this dataset. There are three worksheets to the spreadsheet: 1) Abbrev. - details the abbreviations used in worksheets 2 and 3. 2) Table 3 - Table 3 data entered from ANARE Research Notes 58. 3) Transposed Table 3 - The same data as worksheet 2, but arranged differently. A pdf copy of ANARE Research Notes 58 is also available for download at the URL given below. A paper written in 2006 about pigments in microalgae, which provides some up-to-date explanations about pigmentation, is also available for download, but owing to copyright restrictions, is only available for download by Australian Antarctic Division personnel. The fields in this dataset are: Date Time (GMT) Latitude Longitude Depth (metres) Pigment concentration (nanograms per litre) chlorophyllide a chlorophyll c methyl chlorophyllide a phaeophorbide a peridinin 19'-butanoyloxyfucoxanthin fucoxanthin 19'-hexanoyloxyfucoxanthin Neoxanthin Prasinoxanthin Violaxanthin Diadinoxanthin Alloxanthin diatoxanthin Zeaxanthin Canthaxanthin Unknown Chlorophyll b Chlorophyll a allomer Chlorophyll a Chlorophyll a epimer Phaeophytin a derivative Phaeophytin b Phaeophytin a Chlorophyll a total % Degradation Pigment total This work was completed as part of ASAC project 40 (ASAC_40). |
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