Australian Antarctic Science Season 2010–11
Major science projects this season include continued research at Davis on the impacts of climate change and pollution on marine invertebrates; satellite tagging of fledgling emperor penguins; and Arctic-Antarctic comparisons of atmospheric phenomena. At Casey the ICECAP project enters its third and final season while at the Totten Glacier, scientists will measure the contribution of the glacier’s drainage basin to sea level rise and provide validation measurements for the CryoSat-2 satellite mission. At Mawson and Davis a hydrographic survey will map the sea floor to identify changes caused by local human activities and future climate-related impacts (such as greater iceberg scouring). A major marine science voyage to the Mertz Glacier region will begin studying the impacts of an iceberg calving event from the glacier tongue in February 2010. View the full list of 2010–11science projects. View a larger version of the map at right (pdf format)
Hydrographic survey: A ‘multibeam swathe mapper’ (a type of depth sounder) is being used to create a detailed three-dimensional picture of the sea floor at Mawson and Davis. The swathe mapper sends out a beam of sound on either side of the boat and the returning echo provides depth information in a broad path or swathe. This depth data allows scientists to visualise sea floor features, including iceberg scouring. Regular disturbance of the sea floor by icebergs is expected to favour some marine species and disadvantage others, creating distinctive biological communities. The technology will help scientists document the scale of impact caused by humans, and the potential impacts of future climate change driven by key processes such as changes in sea ice. This information will contribute to environmental management to protect Antarctic coastal ecosystems.
Photo: Wendy Pyper
Physical sciences: A number of instruments based at Mawson measure space and atmospheric phenomena. They generally operate remotely and automatically send data to servers in Australia. They include cosmic ray telescopes to measure particle radiation from the sun and outside the solar system, an induction magnetometer to measure ultra low frequency space plasma waves, a geomagnetic observatory to measure changes in the earth’s magnetic field and a riometer to measure changes in the ionosphere (above 90 km). The data feed into climate research and models and space weather forecasts.
The Amery Ice Shelf Ocean Research (AMISOR) project is part of a broad umbrella study of the entire Lambert Glacier Basin–Amery Ice Shelf system, to understand both the climatic history of the region and its probable response to global warming. Read the story in this issue.
- Developing sediment and water quality guidelines for Antarctica: This project looks at the effects of common contaminants such as petroleum hydrocarbons and metals and their interactions with environmental variables, including temperature and salinity, on a range of Antarctic organisms from micro-algae to macro-invertebrates. Last season toxicity tests were conducted (in a new field aquarium) to study the potentially synergistic effects of copper, cadmium, lead, zinc and nickel, and changes in temperature and salinity. This season the work will expand to include new test species. From this research, risk assessment techniques and environmental guidelines for the protection and remediation of sites will be developed.
- Ocean acidification impacts on marine benthos: Last season, experiments examining the impact of ocean warming and ocean acidification on juvenile sea urchins (Abatus nimrodi) were conducted by scientists from the University of Sydney, University of Tasmania and the Australian Antarctic Division. This season scientists will look at the impact of ocean warming and acidification on the early life history stage of other invertebrates. By examining the impact on planktonic and benthic life stages of ecologically important calcifying organisms (organisms that form shells or structures of calcium carbonate) and non-calcifying organisms, predictions can be made on the potential vulnerability of marine biota to climate change and the potential ‘winners’ and ‘losers’ of climate change.
- Assessing oil toxicity to benthic invertebrates: This Southern Cross University-led project is assessing the ecological risks of oil contaminants associated with fuel use in Antarctic waters, by studying the behaviour, bioavailability and toxicity of commonly used fuels including SAB (Special Antarctic Blend) to the sensitive early-life stage of Antarctic marine invertebrates. The project will provide a scientific basis for better managing fuel carriage and transfer in the Antarctic and for developing spill contingency plans.
- Resilience of marine invertebrates to climate change: This project looks at how the distribution of marine invertebrates is maintained through processes such as larval dispersal or isolation, and how these processes may be affected by environmental change. This season scientists will continue experiments to understand how changes in ocean temperature and salinity might affect the dispersal potential of invertebrate larvae, in terms of their developmental time and behavioural changes. Scientists will also sample larvae for genetic analysis to identify the origin of larvae in the water column and determine how far they have dispersed from their parent populations. Read the story in this issue.
Emperor penguins: Last season, scientists trialled some new satellite trackers on emperor penguin fledglings at Amanda Bay, to follow the development of diving capability over about four months. This year similar tags will be deployed on fledglings and some adults to see whether there is any overlap between the foraging areas of juveniles and adults in summer. For more information see Australian Antarctic Magazine 15: 11, 2008.
Photo: John French
The Davis lidar will also be used to study the optical properties of fine particles in the 5–30 km altitude range. Some of these particles may be associated with smoke from fires in Southern Hemisphere continents, particularly Africa and South America. The sources of any aerosol layers measured will be identified using two different models of atmospheric transport. The work will provide insights into the evolution of smoke particles over Antarctica, which may help improve calculations of solar heating. The data will also be made available for validating the upcoming Glory satellite mission.
Seabird monitoring: Automated cameras will be set up to monitor Adélie penguin nesting sites at breeding locations near Casey and Davis stations to extend our understanding of Adélie penguin population dynamics over broader environmental conditions. Satellite trackers will be attached to fledgling Adélie penguins and geo-locator tags will be fitted to adult snow petrels to learn about their winter migratory routes and foraging locations. Other sites near Casey and Davis will be assessed for the set up of automated cameras for monitoring other seabird species, and for their suitability for tracking studies. Broad-scale surveys of penguin breeding sites will be conducted along the coastline around both stations.
Moss bed monitoring: A remote-controlled ‘OktoKopter’ – an eight-rotor helicopter – will be used to map the extent of moss beds at Casey and Windmill Islands. Read the story in this issue.
Remediation projects: These include ongoing research into the cost-effective clean up of petroleum spills in the Antarctic and other cold regions, and development and application of technologies to clean-up heavy metal contaminants from abandoned waste disposal sites.
ICECAP: December sees the return of the ICECAP project (‘Investigating the Cryospheric Evolution of the Central Antarctic Plate’) to Casey. Read the story in this issue.
GPS devices and meteorological sensors will be deployed at six sites, to measure ice elevation and movement. The sensors will also measure the water content of the atmosphere, which can be directly compared to values used for the CryoSat-2 satellite data. These six sites will also provide reference points for an airborne survey by the Alfred Wegener Institute (AWI). The AWI aircraft will be equipped with a laser altimeter and an airborne replica of the radar device used on the CryoSat-2 spacecraft. These data, combined with in-situ surveys of the ice sheet, will assist calibration of the ESA mission, ensuring accurate estimates of how Antarctica is responding to climate change.
Ongoing projects on Macquarie Island include: developing low-risk, low-cost, on-site remediation techniques to clean up fuel spills; investigating the status and trends of recovering fur seal populations; investigating why an endemic cushion plant appears to suffering from rapid die-back; and looking at how subantarctic organisms and ecosystems respond to change caused by global warming, feral animals and weedy plant species.
Mertz Glacier: This season sees a major marine science voyage to the Mertz Glacier region, after a large iceberg collided with the Mertz Glacier tongue in February, snapping off about 80% of the tongue. The resulting 78 km-long iceberg changed the geography of the region, which is expected to affect ocean circulation in the Mertz polynya (an area of open water). A number of research projects will be conducted by the Antarctic Division, CSIRO, the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), and others, to study the impact on the local environment. Opportunistic projects will also be conducted, continuing long-term marine and ice-edge research.
Photo: Keith Martin-Smith
- Marine microbes – A number of projects will sample marine microbes (algae, bacteria and protozoa) from the Mertz region as part of broader-scale studies. An Australian Antarctic Division project will test the hypothesis that krill control the ice-edge phytoplankton bloom by grazing on phytoplankton and exporting their accumulated iron to depth as faecal pellets, limiting further growth. To do this, ratios of iron-containing proteins (ferredoxin and flavodoxin) will be measured in the microbial community as proxies for iron limitation. Microscopy and pigment analysis will also be used to identify community composition and individuals within the community. Characteristics of ‘keystone’ species that play important functional roles in the community will be examined, including carbon content, cell volume and chlorophyll composition. This work will contribute to food web and carbon flux models.
- DNA sequence analysis of the microbial community will also be undertaken by University of NSW scientists involved in the Australian Southern Ocean Genome-Based Microbial Observatory. The work will identify cryptic species (species that are difficult to separate based on physical features) and very small organisms that can’t be visualised by microscopy. It will also contribute to the molecular characterisation of the keystone species within communities.
Photo: John Bowman
- Finally, a type of microalgae known as ‘Parmales’ will be collected. Parmales are components of ‘marine snow’ and part of the diet of grazers such as krill and protozoa. This Australian National University project aims to separate and concentrate Parmales from the marine microbial community using a flow cytometer. This instrument allows individual cells in a sample to be identified and removed for further study. Once concentrated, microscopy, pigment analysis and DNA sequencing will be used to begin classifying them and understanding their ecological role.
- Physical oceanography – The Mertz Glacier region plays an important role in the global ocean overturning circulation – a pattern of ocean currents that strongly influences climate. Polynyas in the region (areas of open water or low sea ice concentration) produce about 25% of the Antarctic Bottom Water (cold, salty water), which drives the overturning circulation, carrying oxygen and nutrients to the ocean depths in all ocean basins. This project will measure the export of Antarctic Bottom Water from the Mertz region and broader Adélie Land coast, as well as temperature, salinity and oxygen. These measurements will be compared to earlier observations to detect how the Southern Ocean limb of the overturning circulation is responding to the geographic changes caused by the glacier tongue calving, and longer-term climate change.
A second project will test a safety feature of the Explorer Autonomous Underwater Vehicle (AUV) for its planned missions under the Antarctic sea ice. The safety feature – the ‘beacon system’ –provides an acoustic ‘heartbeat’ during normal operation, warns of a major fault, and uses as a range-meter for emergency location. During under-ice operations the AUV will carry an upward-looking sonar, to map the underside of sea ice; a hyper-spectral radiometer for measuring light passing through the ice and snow cover (under-ice irradiance); and a fish echo sounder to detect the presence of fish.
New 10 year science strategic plan
Photo: Gary Bolithio
The plan will guide the Australian Antarctic Science Program over the next 10 years to focus efforts within four thematic areas:
- Theme 1 – Climate processes and change
- Theme 2 – Terrestrial and nearshore ecosystems: environmental change and conservation
- Theme 3 – Southern Ocean ecosystems: environmental change and conservation
- Theme 4 – Frontier Science
Themes 1, 2 and 3 address the priority science needs articulated by government policy and resource management agencies. The research in these themes will be designed to link monitoring, observational and experimental science with the required process studies, synthesis and integrative modelling. It will also provide scientific input to policy-makers and conservation and resource managers. There will be increased emphasis on delivering project and program outputs and products to the end-user community. The Frontier Science theme will encourage and support research that falls outside the priorities of other thematic areas, but within Australia’s national science priorities.
During October scientists working within the Australian Antarctic program met to develop an implementation plan for the strategic plan. Expressions of Interest for projects that address the research priorities identified during the workshops will be assessed against these priorities.