This project used computer-based modelling and existing field data to analyse the production and cycling of dimethylsulphide (DMS) and predicted its role in climate regulation in the Antarctic Southern Ocean. From the Final Report: Aims (i) To calibrate an existing dimethylsulphide (DMS) production model in a section of the Antarctic Southern Ocean. (ii) To use the calibrated model to investigate the effect of GCM-predicted climate change on the production and sea-to-air flux of DMS under current and enhanced greenhouse climatic conditions. (iii) To provide regional assessments of the sign and strength of the DMS-climate feedback in the Southern Ocean. Characteristics of Study Region: Our study region extends from 60-65 degrees S, 123-145 degrees E in the Antarctic Southern Ocean, and was the site of a major biological study in the austral summer of 1996 (Wright and van den Enden, 2000). Field observations show that a short-lived spring-summer bloom event is typical of these waters (El-Sayed, 1988, Skerratt et al. 1995); however there can be high interannual variability in the timing and magnitude of the bloom (Marchant and Murphy, 1994). The phytoplankton community structure has been described by Wright and van den Enden (2000), who report maximum chlorophyll (Chl) concentrations during January-March in the range (1.0-3.4) microgL-1. During this survey, macronutrients did not limit phytoplankton growth. Thermal stratification of the mixed layer was strongly correlated with high algal densities, with strong subsurface Chl maxima (at the pycnocline) observed. The mixed layer depth determined both phytoplankton community composition and maximum algal biomass. Coccolithophorids (noted DMS producers) were favoured by deep mixed layers, with diatoms dominating the more strongly stratified waters. Pycnocline depth varied from 20-50 m in open water. Algal abundance appeared to be controlled by salp and krill grazing. Field data support the existence of seasonal DMS production in the Antarctic region. However, a large range in DMS concentrations has been reported in the open ocean , reflecting both seasonal and spatial variability (Gibson et al., 1990, Berresheim, 1987; Fogelqvist, 1991). Blooms of the coccolithophores, and prymnesiophytes such as Phaeocystis, form a significant fraction (~23%) of the algal biomass (Waters et al 2000). Concentrations of DMS in sea ice are reported to be very high (Turner et al. 1995) and may be responsible for elevated water concentrations during release from melt water (Inomata et al. 1997). Field measurements of dissolved DMS made in the study region have been summarised by Curran et al. (1998). DMS concentrations were variable in the open ocean during spring and summer (range: 0-22 nM), with the higher values recorded in the seasonal ice zone and close to the Antarctic continent. Zonal average monthly mean DMS in the study region have been estimated by Kettle et al. (1999). (See downloadable full report for reference list). A copy of the referenced publication is also available for download by AAD staff. It contains the modelling information.

Metadata record for data from ASAC Project 2320 See the link below for public details on this project. ---- Public Summary from Project---- The project explores the extent to, and the manner in, which the El Nino-Southern Oscillation (ENSO) phenomenon influences the Antarctic and subantarctic region, particularly in the Pacific sector. Recent changes in Antarctic climate will be assessed in light of changes in ENSO activity. In this project, the NCEP reanalysis datasets were sourced from: NOAA/National Weather Service, National Centers for Environmental Prediction (5200 Auth Road, Camp Springs, Maryland, 20746 USA). Two NCEP reanalysis data sets were used in this study. The first was NCEP/NCAR, with 6-hourly data available from 1958 (see the URL provided below for further information). The second was the NCEP/DOE set, with 6-hourly data available from 1979 (see the URL provided below for further information). In this project the following model/analysis was applied: Application of The University of Melbourne cyclone tracking scheme (Simmonds et al., 2003, Monthly Weather Review, 131, 272-288) and a broad range of statistical tests. Brief details are provided in the Summary. See the link for the pdf document for more detailed information. These complex statistical analyses were run over the entire length of the project (2002/2003 - 2004/2005). They were run on the Sun Workstation cluster in the School of Earth Sciences, The University of Melbourne.

This indicator is no longer maintained, and is considered OBSOLETE. INDICATOR DEFINITION The fecundity (pupping rates) of female fur seals and the growth rates of their pups relative to changes in sea surface temperatures (local primary production) in the vicinity of Macquarie Island. TYPE OF INDICATOR There are three types of indicators used in this report: 1.Describes the CONDITION of important elements of a system; 2.Show the extent of the major PRESSURES exerted on a system; 3.Determine RESPONSES to either condition or changes in the condition of a system. This indicator is one of: CONDITION RATIONALE FOR INDICATOR SELECTION A highly negative correlation has been detected between sea surface temperatures in the vicinity of Macquarie Island and fur seal fecundity and pup growth. A dataset of over ten years has shown that autumn sea-surface temperatures are highly negatively correlated with female fecundity in the following breeding season. Rather than the reproductive success in terms of fecundity and pup growth being seen simply as a correlate of SST and presumably ocean productivity, the measure is much more than this. What the dataset from the Macquarie Island fur seal populations is rather more unique, in that they indicate how environmental variability effects the reproductive success of animals at annual and lifetime scales. This is especially important as we can now show what impacts environmental/climatic phenomena such as the Antarctic Circumpolar Wave, and global warming will have on fur seals, and how changes in the environment may impact on the viability of populations. In this situation, the data clearly suggest that warmer ocean temperatures significantly effect the reproductive success of fur seals. Sustained warmer temperatures would therefore impose demographic constraints on populations. DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM Spatial scale: SST data are obtained from a 1 degree square just north of the island that represents the region in which most females obtain food throughout their lactation period. Frequency: Data on the reproductive success of fur seals is to be collected annually. Measurement technique: Each breeding season (November-January), the reproductive success of tagged females is monitored, including their pupping success, and the growth rates of their pups. RESEARCH ISSUES LINKS TO OTHER INDICATORS

Distribution, abundance and dates of relict Adelie Penguin colonies in the Australian Antarctic Territory (AAT). Current mapping efforts have focused on the Windmill Islands in preparation for a PhD study to commence in 2004/05 with the two investigators. The planned PhD study will work at either the Windmill Islands or the Vestfold Hills. This project integrates ASAC projects 1219 and 1322 (ASAC_1219, ASAC_1322). The fields in the excel spreadsheet are: Radiocarbon Samples Isotope Samples Site - list of precise locations provided in the downloadable paper Level - horizontal stratum (depth), given in 5cm blocks Species Material Weight (g) Notes Lab no. Uncorrected Date (BP) - (day) Standard Deviation Delta R - range of corrected date for sample, 2 standard deviations either side of the mean Mean - estimated mean of sample date See the paper included in the download file for further information.

Locations of sampling sites for ASAC project 40 on rotation 4 of the French polar supply ship L'Astrolabe in the 2004/2005 season. Samples were collected between February and March of 2005. The final dataset will contain information on chlorophyll, carotenoids, coccolithophorids and species identification and counts. Public Summary from the project: This program aims to determine the role of single celled plants, animals, bacteria and viruses in Antarctic waters. We quantify their vital role as food for other organisms, their potential influence in moderating global climate change through absorption of CO2 and production of DMS, and determine their response to effect of climate change. For more information, see the other metadata records related to ASAC project 40 (ASAC_40). The fields in this dataset are: Tube label Date(UTC) Time(UTC) LongDecdecimaldegrees LatDecdecimaldegrees Local time (dec hrs)actual solar local time (decimal hours) calc from longitude DOES NOT EQUAL TIME ZONE Sea Tempdegrees Celsius Ice present/absent Lugol's#microscope sample number for phytoplankton ID (Our use only) HPLC Vol volume filtered for HPLC pigment analysis (Our use only) Cocco Vol volume filtered for coccolithophorid counts (Our use only) Cocco tray No.(Our use only) Net Sample Time

This dataset contains locations of sampling sites for ASAC project 40 on rotation 0 of the French polar supply ship L'Astrolabe in the 2007/2008 season. Samples were collected between October and November of 2007. It also contains information on chlorophyll, carotenoids, coccolithophorids and species identification and counts. Public Summary from the project: This program aims to determine the role of single celled plants, animals, bacteria and viruses in Antarctic waters. We quantify their vital role as food for other organisms, their potential influence in moderating global climate change through absorption of CO2 and production of DMS, and determine their response to effect of climate change. For more information, see the other metadata records related to ASAC project 40 (ASAC_40). The fields in this dataset are: Tube label Date(UTC) Time(UTC) Local time (dec hrs)actual solar local time (decimal hours) calc from longitude DOES NOT EQUAL TIME ZONE Longitude decimal degrees/degrees, minutes Latitude decimal degrees/degrees, minutes Sea Temperature degrees Celsius Ice present/absent Lugol's bottle # - microscope sample number for phytoplankton ID (Our use only) HPLC Volume remaining - volume filtered for HPLC pigment analysis (Our use only) Volume filtered for HPLC Volume remaining for Coccoliths Coccolith tray No.(Our use only) Coccolith tray position number Net Sample Time Fluorescence

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.

This dataset contains the locations of sampling sites for ASAC project 40 on rotation 2 of the French polar supply ship L'Astrolabe in the 2002/2003 season. Samples were collected between December and January of 2002/2003. It also contains the final dataset which has information on chlorophyll, carotenoids, coccolithophorids and species identification and counts. Public Summary from the project: This program aims to determine the role of single celled plants, animals, bacteria and viruses in Antarctic waters. We quantify their vital role as food for other organisms, their potential influence in moderating global climate change through absorption of CO2 and production of DMS, and determine their response to effect of climate change. For more information, see the other metadata records related to ASAC project 40 (ASAC_40). The fields in this dataset are: Voyage Tube Label Date (UTC) Time (UTC) Time (Local) Nominal Depth (m) Latitude Longitude Sea Temperature Ice (Presence or Absence - 1 or 0 respectively) Coccolithophorid sample (yes or no) Plankton Net Sample Chlorophyll a (micro grams per litre)

This dataset contains locations of sampling sites for ASAC project 40 on rotation 2 of the French polar supply ship L'Astrolabe in the 2007/2008 season. Samples were collected between December 2007 and January of 2008. It also contains information on chlorophyll, carotenoids, coccolithophorids and species identification and counts. Public Summary from the project: This program aims to determine the role of single celled plants, animals, bacteria and viruses in Antarctic waters. We quantify their vital role as food for other organisms, their potential influence in moderating global climate change through absorption of CO2 and production of DMS, and determine their response to effect of climate change. For more information, see the other metadata records related to ASAC project 40 (ASAC_40). The fields in this dataset are: Tube label Date(UTC) Time(UTC) Local time (dec hrs) actual solar local time (decimal hours) calc from longitude DOES NOT EQUAL TIME ZONE Longitude decimal degrees/degrees, minutes Latitude decimal degrees/degrees, minutes Sea Temperature degrees Celsius Ice present/absent Lugol's bottle # - microscope sample number for phytoplankton ID (Our use only) HPLC Volume remaining - volume filtered for HPLC pigment analysis (Our use only) Volume filtered for HPLC Volume remaining for Coccoliths Coccolith tray No.(Our use only) Coccolith tray position number Net Sample Time Fluorescence

Locations of sampling sites for ASAC project 40 on Voyage 7 of the Aurora Australis, 1993-1994 - SHAM samples. Public Summary from the project: This program aims to determine the role of single celled plants, animals, bacteria and viruses in Antarctic waters. We quantify their vital role as food for other organisms, their potential influence in moderating global climate change through absorption of CO2 and production of DMS, and determine their response to effect of climate change. For more information, see the other metadata records related to ASAC project 40 (ASAC_40). The fields in this dataset are: Sample # Filename Date CTD # Latitude Longitude Depth (m) Temperature (degrees C) Chlorophyll a (micrograms per litre)