Chlorophyll data was used to measure growth rates of sea ice algae in CO2 incubations. Sea ice brine microalgae was collected from sackholes. Replicate samples were incubated in ambient air (~0.04% CO2), 0.1% CO2, 1.0% CO2 and 2.0% CO2 concentrations. Three incubation experiments were carried out at SIPEX stations 4 (expt 1) 7 (expt 3) and 8 (expt 4). Growth rate calcualtions followed a standard exponential growth model, i.e Bf = Bi x e(rt) Where Bf equals final biomass, Bi equals initial biomass, r = growth rate and t = time (in days).

Data were obtained from vertical profiles of a Fast Repetition Rate Fluorometer (FRRF, Chelsea FASTocean). The full set of parameters available are reported here. FRRF data have been integrated with on board ship data to add location, time. Parameters: Ship parameters Cruise Station Type Date Time Longitude Latitude Bottom depth Depth (of FRRF) FRRF parameters PMTeht (photomultipier) ADC PAR F light F0 Fm light Fm Fv light Fv Fq FvFm Sigma Sigma light NPQ RCII conc Jpsii JVpsii Alhii Chl conc For a table defining these units see Oxborough, K. Moore, C.M., Suggett, D.J., Lawson, T., Chan, H.G. and Geider, R.G. Direct estimation of functional PSII reaction centre concentration and PSII electron flux on a volume basis: a new approach to the analysis of Fast Repetition Rate fluorometry (FRRf) data. Liminology and Oceanography: Methods - 2012, 10:142-154. https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lom.2012.10.142)

Sea ice covers up to 20 million km2 of the Southern Ocean. When present it supports a vigorous ecosystem that provides energy and food for all other marine organisms. Using the latest micro sensor technology, we are examining the factors that effect the productivity of this vital link in the Antarctic marine food web. New data were added to this metadata record in January 2011. These data included FRRF data collected on the CEAMARC, CASO, SIPEX and SAZ-SENSE voyages. A word document in the download file provides details about these datasets, plus those collected on Voyage 1 2009-2010, and voyage 2 2008-2009. The download file also contains a folder labelled "Older data". This data is described below: An explanation of the excel spreadsheet in the download file is as follows: Worksheet 1 is the chlorophyll data Worksheet 3 is the location data CHLOROPHYLL DATA Column A is sample name, the first letter refers to the location data in worksheet 3, the second to the ice flow number and the third to the replicate number Section refers to depth in ice core, measured from the bottom Ignore C Column D is the total volume of melted ice Column E is the volume of D that was filtered Column G is the Fluorometer reading before the addition dilute HCl Column H is the fluorometer reading after the addition of acid Column I is the calculation of chlorophyl concentration in the sample Column K is areal chlorophyll estimate Column L is the mean for the core Column N is the mean for the site Column O is the standard deviation LOCATION DATA Lat, longs and times of each sampling. The first set (B-G) refers to the time sampling started, the second (H-M) to when it finished Project objectives: - Determine the net photosynthesis and primary productivity of the phytoplankton and major sea ice algal communities of the Eastern Antarctic Sea Ice Zone (SIZ). Estimate seasonal and annual algal production and inter annual variability - Obtain data on biomass distribution and variability to establish regional relationships between ice thickness, snow cover, and biomass - Determine the effects of a) Light b) Nutrients (principally nitrate and iron) c) Temperature on photosynthesis and primary production - Determine whether the biomass and productivity of the phytoplankton and sea ice algae in winter and spring limits the biomass or growth of krill - Estimate the effects of climate change on Sea ice Zone primary production Taken from the 2008-2009 Progress Report: Progress against objectives: This project used V2, a spring voyage, to collect underway data to determine surface biomass and primary production. Biomass samples (chlorophyll a) were taken every 3 hours. Productivity estimates by PAM were also made every 3 hours. Productivity measurements by FRRF were made every 1 minute. Nutrient samples were taken at the same time as the biomass samples. Analysis of the biomass samples is complete. Preliminary analysis of the productivity data has commenced. This data is being used for a Masters project (Rob Johnson, IASOS). An iron addition experiment accompanied this monitoring. Iron was added to samples taken every 3 hours and the change in photosynthesis (maximum quantum yield) measured with a PAM. The rate of recovery from iron stress was the principal focus. Most of this data has been submitted as metadata. Using The PAM and FRRF simultaneously also enabled a comparison to be made between these different ways of measuring photosynthesis. Progress was also made on the analysis of FRRF productivity and biomass data collected over several years on the L'Astrolabe transect. Analysis involves quantitative manipulation of FRRF data and correlation with chlorophyll, nutrients, temperature and other biological parameters. A publication arising from this work will be submitted this year. Taken from the 2009-2010 Progress Report: Progress against objectives: We participated in V1 of the Aurora Australis, spring 2009. The objective of this project was to measure surface primary production off East Antarctica. Photosynthetic parameters of phytoplankton under actinic light (L) as well as in darkness (D) were measured using a fast repetition rate fluorometer (FRRF). The parameters included the maximum photochemical efficiency (Fv/FmL,D), the functional absorption cross section of photosystem II (sPSII,L,D) and a turnover time of electron transfer (tL,D). Chlorophyll a concentration was measured by using Turner fluorometer. The photosynthetic parameters, irradiance and chlorophyll a concentration will then be used to estimate primary production of phytoplankton. This field program particularly focussed on the first of the listed objectives, ie 'Determine the net photosynthesis and primary productivity of the phytoplankton and major sea ice algal communities of the Eastern Antarctic Sea Ice Zone (SIZ). Estimate seasonal and annual algal production and inter annual variability'. We have been collecting FRRF-based primary production data from each season and the 2009 data provides the late spring data to supplement data from autumn, winter and summer, collected in previous seasons. We have now built up a comprehensive assessment of season variability which will enable a reliable estimate of annual primary production. These analyses will also provide a detailed snap shot of primary production with which to compare future changes. Preliminary analysis shows clear patterns of variation in Fv/Fm, a parameter that is particularly sensitive to low iron concentration. This data is shown on an accompanying diagram. Productivity analysis is still underway. Much of the work for this project forms part of the PhD project of Cheah Wee.Wee is expected to finish his PhD by December 2010 and it is anticipated that all data analysis for the project will have been completed and the finished manuscripts submitted for publication. He has already had one manuscript form this project accepted (Cheah et al, 2010).

The productivity of Antarctic waters may be controlled by the amount of iron. Experiments have shown that this is probably the case for phytoplankton but as yet we do not know if iron limits the growth of sea ice algae. This study will assess whether iron limits sea ice algae production and will conduct experiments to work out how these algae use iron. Measurements have been made to determine whether sea ice algae are limited by Fe. Sea ice samples were taken and this spreadsheet refers to those ice cores Columns A-G are self explanatory Column G is the depth in the ice core from the bottom Column H is the chlorophyll concentration in mg Chl m-2 Column I is the phaeophytin concentration in mg m-2 J is the total amount of protein in the sample ng m-2 K is the total amount of the protein flavodoxin ng m-2 L is the total amount of ferrodoxin ng m-2 These last two enable the Fe limitation status to calculated (not completed).

1. In situ chlorophyll fluorescence measurements using pulse amplitude technique (PAM) of macroalga Desmarestia menziesii, assessing adaptation to high light exposure after sea ice breakout, and impact of Thala Valley tip wastes. 2. In situ chlorophyll fluorescence measurements using pulse amplitude technique (PAM) of sediment diatom material assessing adaptation to high light exposure after sea ice breakout, and impact of Thala Valley tip wastes. 3. In situ chlorophyll fluorescence measurements using pulse amplitude technique (PAM) of sponge Latrunculia decipiens assessing adaptation to high light exposure after sea ice breakout. 4. Ecotoxicological experiments where Desmarestia menziesii was exposed to copper in indoor aquaria, aim to determine EC50, NOEC, LOEC for copper. 5. Field collections of various macroalgae for stable isotope analysis: for determination of physiological mechanisms. 6. Field collections of sponge and diatom material for pigment analysis.

The data comprise images (encapsulated postscript and PNG formats) showing the integrated solar irradiance exposure of sea ice. The exposure value for ice at a given grid point was calculated by computing the motion trajectory of that patch of ice across the autumn/winter season (1-March to 1-November). Daily motion data were obtained from the National Snow and Ice Data Center (http://nsidc.org/data/nsidc-0116.html). The integrated radiation exposure was then calculated using daily estimates of downward solar flux from the NCEP/NCAR re-analyses. The values shown in the images are cumulative photosynthetically active radiation expressed in W-days/m^2. Please contact the data custodian before using these data. This work was done as part of ASAC project 2943 (ASAC_2943). See the link below for public details about the project.

This is a parent metadata record for work carried out as part of ASAC/AAS project 40. See the child metadata records for further information. More than 95% of the biomass in the Southern Ocean is microscopic - single celled plants, animals, bacteria and viruses. We are studying the factors that control their distribution and abundance - oceanographic and seasonal conditions, their physiology, and grazing - in order to model their vital roles as food for other organisms and their influence in moderating global climate change through absorption of CO2 and production of DMS. We are also addressing the changes expected in microbial communities through effects of climate change - global warming, sea ice retreat, ocean acidification and enhanced ultraviolet radiation. This project aims to determine the role of microorganisms in the Southern Ocean. The major objectives are to: * Identify and quantify key protistan components of the Southern Ocean ecosystem and study their autoecology. * Identify environmental and ecological processes that control abundance of key microbial components. * Determine interactions between key microbial components to quantify major pathways of carbon flow. * Determine the activity and viability of bacterioplankton and protists in the Southern Ocean. * Distinguish different microbial communities by identifying key taxa and associations so that processes such as primary production, respiration, grazing and particle flux can be readily parameterised in ecological models. * Determine the effect of elevated CO2 concentrations on microbial populations and processes. Taken from the 2008-2009 Progress Report: Progress against objectives: 1. Ongoing sampling from Astrolabe has continued, with 3 return voyages being sampled for phytoplankton species, chlorophyll a and other pigments, coccolithophorid counts and DNA profiles, in conjunction with measurements of CO2, ocean structure, fluorescence and ocean colour by CSIRO / CRC colleagues. 2. Three sets of minicosm experiments were conducted at Davis station with 7 staff spending 4.5 - 5.5 months on site. These experiments consistently found that acidification caused blooms of nanoplanktonic diatoms and increased bacterial activity, apparently by inhibition of microheterotroph grazers, at the expense of larger cells that are more readily ingested by grazers such as krill. We showed for the first time in Antarctic waters that pCO2 affects the structure and function Antarctic microbial communities in a way that may reduce food availability to large grazers. Over 100 cultures of "winners and losers" from such experiments were isolated and returned to Australia. These will form the basis for further physiological experiments including molecular assays. 3. Submission and acceptance of 8 papers from the BROKE-West cruise (5 as senior author). These showed the interactions between bottom-up (micronutient) top-down (grazing) control in structuring microbial populations in the marginal ice zone. Five biogeographic zones were identified on the basis of species composition, and the productivity was measured for each zone. Microzooplankton grazing experiments found that grazing within that microbial loop consumed a significant proportion of new productivity. In some areas later in the season, all productivity was consumed by microheterotrophs, rather than metazoans such as krill. A time sequence was identified for seeding and development of components of ice edge blooms, subsequent grazing and decline and a mechanism postulated for export of micronutrients (e.g. iron) by grazing and sedimentation that prevents subsequent development of surface water blooms and constrains populations to a deep chlorophyll maximum below the level of a nutricline. 4. Detailed analysis of greater than 30 strains of keystone species Emiliania huxleyi of two morphotypes in conjunction with Clara Hoppe (Masters student, Alfred Wegener Institute) and Suellen Cook (PhD student, University of Tasmania) showed consistent differences between strains in terms of pigmentation, responses to light and genetics. The two morphotypes appear to be adapted to different mixing regimes north and south of the Polar Front; the southern form may represent a new species. For a full list of references associated with this project, see the project link at the provided URL.

Some scanning electron microscope images were taken of dinoflagellates sampled as part of this project. A catalogue of the images taken is provided as part of the download file at the provided URL. The images are currently held by the Electron Microscope Unit of the Australian Antarctic Division, but have not yet been entered into their electron microscope database (as at the 30th of April, 2004). From the abstracts of the referenced paper: The abundance and biomass of ciliates, dinoflagellates and heterotrophic and phototrophic nanoflagellates were determined at three sites along an ice-covered Antarctic fjord between January and November 1993. The water column showed little in the way of temperature and salinity gradients during the study period. In general, the protozooplankton exhibited a seasonal variation which closely mirrored that of chlorophyll a and bacterioplankton. The fjord mouth, which was affected by the greatest marine influences, consistently had the highest densities of ciliates and the most diverse community, with up to 18 species during the sampling period. Small aloricate ciliates were present throughout the year with Strobilidium spp. being dominant during the winter. Larger loricate and aloricate ciliates became more prominent during January and November, along with the autotrophic ciliate Mesodimium rubrun and two mixotrophic species (Strombidium wulffi and a type resembling Tontonia) suggesting evidence of species successions. Data on dinoflagellates were less extensive, but these protists showed greatest species diversity in the middle reaches of the fjord. A total of 13 species of dinoflagellate were recorded. Ciliates made a significant contribution to the biomass of the microbial community in summer, particularly in the middle and at the seaward end of the fjord. In winter, heterotrophic flagellates (HNAN) and phototrophic nanoflagellates (PNAN) were the dominant component of protistan biomass. In terms of percentage contribution to the microbial carbon pool, bacteria dominated during winter and spring. To the authors' knowledge, this is the first seasonal study of an Antarctic fjord. The Ellis Fjord is very unproductive compared to lower latitude systems, and supports low biomass of phytoplankton and microbial plankton during most of the year. This relates to severe climatic and seasonal conditions, and the lack of allochthonous carbon inputs to the system. Thus, high latitude estuaries may differ significantly from lower latitude systems, which generally rank among the most productive aquatic systems in the world. The fields in this dataset are: EMU Image Number Fiona Scott Image Number Species SEM Stub Number Location Collector

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).

This record relates to the Australian component of the Latitudinal Gradient Project. The LGP is largely a New Zealand, US and Italian venture, but a small contribution has been made by Australian scientists. The Australian component of this work was completed as part of ASAC projects 2361 and 2682 (ASAC_2361, and ASAC_2682). Data from this project were entered into the herbarium access database, which has been linked to this record. The list below contains details of where and when samples were collected, and also the type of sample and the method of sampling. Cape Hallett and vicinity (2000, 2004): Biodiversity assessment of terrestrial plants (mosses, lichens); Invertebrate collections (mites, Collembola); plant ecology and community analysis; photosynthetic physiology of mosses and lichens; molecular genetics of mosses and lichens. Random sampling for biodiversity studies; point quadrats, releves for vegetation analysis, field laboratory experiments for physiological studies. Dry Valleys: Taylor Valley (1989, 1996), Garwood Valley (2001), Granite Harbour (1989; 1994, 1996) - plant ecology; plant physiology; biodiversity; invertebrate collections; molecular genetics of mosses. Random sampling for biodiversity studies; point quadrats, releves for vegetation analysis, field laboratory experiments for physiological studies. Beaufort Island (1996) - plant biodiversity; molecular genetics of mosses. Random sampling for biodiversity studies; point quadrats, releves for vegetation analysis, laboratory studies for molecular genetics. Darwin Glacier (1994): plant biodiversity; molecular genetics of invertebrates and mosses (random sampling for biodiversity; laboratory studies of invertebrate and moss molecular genetics). Project objectives: 1. Investigate the distribution of bryophytes and lichens in continental Antarctica 1a). to test the null hypothesis that species diversity does not change significantly with latitude; 1b). to explore the relationships between species and key environmental attributes including latitude, distance from the coast, temperature, substrate, snow cover, age of ice-free substrate. 2. To continue to participate in the Ross Sea Sector Latitudinal Gradient Project and develop an Australian corollary in the Prince Charles Mountains, involving international collaborators, incorporating the first two objectives of this project. 3. To develop an international collaborative biodiversity and ecophysiological program in the Prince Charles Mountains that will provide a parallel N-S latitude gradient study to mirror the LGP program in the Ross Sea region as part of the present RISCC cooperative program (to be superseded by the EBA (Evolution and Biodiversity of Antarctica) program) to address the above objectives. Taken from the 2008-2009 Progress Report: Progress against objectives: Continuing identification of moss and lichen samples previously collected from Cape Hallett, Granite Harbour and Darwin Glacier region. Lecidea s.l. lichens currently being studied in Austria by PhD student. Field work in Dry Valleys significantly curtailed by adverse weather. Field work planned for Darwin Glacier region and McMurdo Dry Valleys, particularly Taylor Valley and Granite Harbour region was severely curtailed due to adverse weather, helicopter diversions due to a Medical Evacuation, and other logistic constraints. 10 days of field time were lost. Limitations on field travel in Darwin Glacier region restricted the field work to a biologically depauperate region. The Prince Charles Mountains N-S transect, the only continental transect possibility for comparison with the Ross Sea area, unfortunately appears to have been abandoned through lack of logistic support. Taken from the 2009-2010 Progress Report: Identification of samples collected from AAT and Ross Sea Region continued during the year, interrupted significantly by the packing of the collection and transfer of specimens to the Tasmanian Herbarium. Work is now proceeding at the Herbarium with sorting, databasing and incorporation of packets into the Herbarium collection. The merging of the collection provides long-term security of curation and significantly boosts the cryptogam collections (35000 numbers) of the Tasmanian Herbarium.