Australia’s research icebreaker, Aurora Australis, returned to Hobart this morning (Friday 21 January) bringing to an end a highly successful 60 day scientific voyage.
The major program, a survey of antarctic seals, headed by Dr Colin Southwell of the Australian Antarctic Division, is the culmination of five years preparation and development with five other nations. This combined international effort has resulted in one of the largest wildlife surveys ever undertaken and was aimed at estimating the total number of seals in the pack-ice surrounding Antarctica.
It involved counting seals visible on the ice from the ship and from long-range helicopters. Dr Southwell’s team surveyed an area of over a million square kilometres southwards to the Antarctic continent. In addition, the team captured seals on ice floes and attached dive recorders so that their movements and diving behaviour could be studied.
Dr Southwell said “The survey was undertaken to study the southern ocean ecosystem, to provide information for sustainable management of its living marine resources, particularly krill. Without this knowledge it is impossible to predict the effects of krill harvesting on seal populations and on other species such as whales and seabirds.”
A varied marine science program aimed at other components of the ecosystem was carried out in conjunction with the seal survey. Surveys of whales and seabirds, experiments on krill, which form their diet, and studies of phytoplankton were also conducted. Together these studies will provide a clearer picture of the entire food chain in the southern ocean and how it functions.
The ship also delivered a group of five glaciologists to the remote Amery Ice Shelf 200 kilometres from Davis station with tents, snowmobiles, fuel and supplies to last them for six months. The group is using a special hot water ‘drill’ developed by the Australian Antarctic Division to penetrate up to 1 kilometre through the ice into the ocean below to sample the water and sediments, a first for Australia’s Antarctic research program.
Voyage Leader, Rob Easther, said “The logistics of this voyage were more complex than most. At times we had people on ice floes as far apart as a kilometre, helicopters operating hundreds of kilometres from the ship as well as rubber rescue boats in the water on standby, all at the same time. Safety was a major concern as we were literally in the middle of nowhere, totally reliant on our own resources if anything went wrong.”
In addition to the high profile scientific program, the voyage also achieved the re-supply of Macquarie Island, and changed over the wintering crews at Davis and Mawson stations.
The ship was moored in the ice at the Amery Ice Shelf for New Year, a very unique location to celebrate the advent of 2000 held alongside the vessel on the sea-ice as the sun circled the horizon.