Scientists will investigate an ancient Antarctic mystery this season - what kinds of plants and animals exist in the unique marine environment in the Bunger Hills, about 450 kilometres from Casey research station.
Chief Investigator of the Biodiversity of East Antarctica, Underwater and Terrestrial (BEAUT) program, Dr Jonny Stark, said the research will provide the first glimpse of an Antarctic seafloor community, potentially isolated for thousands of years.
"The marine environment around the Bunger Hills is unlike anywhere else in Antarctica," Dr Stark said.
"There's a small marine area that opens up in summer, but it is surrounded by ice.
"There's the Edisto Glacier to the west, the continental ice sheet to the south and east, and an ice shelf to the north, which we think has effectively isolated the area from the Southern Ocean for 3000 or 4000 years.
"It's important to document what the biodiversity looks like now, in a rapidly changing environment, and understand what factors influence it, such as sea ice cover or proximity to the glacier or ice shelf.
"This will contribute to our understanding of East Antarctic biodiversity and help us manage the impacts of human activity in the area."
Dr Stark, in collaboration with scientists from Securing Antarctica's Environmental Future, is working within a wider three-year 'Denman Terrestrial Campaign' that aims to understand the Denman Glacier's history and stability.
The BEAUT component of the campaign will see two scientists surveying mosses, lichens, invertebrates and lake biodiversity in the Bunger Hills and Highjump Archipelago (see map).
Another team, led by Dr Stark, will use remotely operated vehicles (ROVs) to explore beneath the sea ice off the Bunger Hills coast, and take photos, videos and samples.
The ROVs will be deployed on 300 metre-long tethers through 40 centimetre-wide holes drilled into the sea ice. Each deployment will take about 45 minutes and will target sites between 10 and 50 metres deep, progressing to depths of between 100 and 200 metres where possible.
"The ROVs have multiple cameras so that we can see and record the plants and animals on the seabed beneath the ice," Dr Stark said.
"They have laser scalers to scale images, and an underwater positioning system so we can do quantitative scientific surveys and accurately measure where they're located.
"The ROVs also have manipulator arms that allow us to collect organisms from the seabed, or deploy and retrieve instruments like sediment traps or a scoop to collect sediment."
The team will also deploy other scientific instruments, including a tide gauge and current meter to understand the oceanographic conditions in the region, as well as instruments to measure water properties and sample plankton.
"We'll be looking at the whole food web, and the different types of seafloor habitat, to get a comprehensive picture of the marine ecosystem and its biodiversity," Dr Stark said.
Over about five weeks the team aim to visit up to 30 marine sites.
Previous coastal surveys under the sea ice in other parts of East Antarctica have found giant sea spiders, star fish, sea anemones and communities of tube-building worms (polychaetes) that grow up to one metre high.
While Dr Stark thinks these species may be present, the team could also be in for a surprise.
"It will be interesting to see what kind of other large invertebrates or organisms are there," he said.
"But given how isolated the Bunger Hills marine ecosystem is, it could be quite different to what we've found at other sites.
"This will be an opportunity to look at a community that might be more typical of Antarctica thousands of years ago."
