Penguin-cam to keep watch on the waddlers
IT SEEMS no one, and nothing, is safe from the all-seeing gaze of remote camera technology. And it doesn’t get much more remote than Antarctic penguin CCTV.
Over the past six summers scientists working from the Australian research stations of Mawson, Davis and Casey on the East Antarctic coast have set up a network of cameras to record the secret lives of Adelie penguins living in raucous, crowded suburbs along the icy coast.
Next month – weather and sea ice permitting – the network will be extended with the arrival of a team aboard the Aurora Australis to set up a new camera at Cape Denison, Commonwealth Bay, the infamously inhospitable ”home of the blizzard” where Sir Douglas Mawson established base camp for his pioneering Australasian Antarctic Expedition a century ago.
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This summer Australian expeditioners have again set out from Hobart for Antarctica – these days voyaging both by ship and by air – continuing Mawson’s tradition of geographical exploration and scientific studies. The Adelie project is part of an ambitious agenda of summer science by the Australian Antarctic Division and its partners, much of it linked to measuring and documenting the effects of climate change.
”Penguin-cam” begins rolling each October, long before winter conditions ease enough to allow scientists into the field to conduct survey work. With daylight returned to the continent after the long Antarctic night, the solar-powered cameras are programmed to switch themselves on, primed and ready to capture the moment when the first penguins of the season leap out of the Southern Ocean onto the ice, following powerful instinct to waddle back to their birthplace for another breeding season.
The cameras run to a pre-programmed schedule right through the season until the penguins, now expanded by a new generation, return to the sea and the light fails. The images they collect allow scientists an intimate and unprecedented insight into the phenology of the breeding cycle – how its timing is influenced by climate and other factors – as well as providing critical ”census” data, glimpses of penguin behaviour, and opportunities to compare the unfolding narratives of populations spread far and wide along the coast and islands.
”We’ve surveyed over 3000 kilometres of coastline now, and some 2000 islands for the presence or absence of breeding sites, and mapped the current breeding distribution of Adelies,” says the Antarctic division’s Dr Colin Southwell, who oversees the Adelie project and leads a research program that provides ongoing monitoring of seabird status and trends across East Antarctica.
While over on the west of the continent, including along the Antarctic Peninsula, Adelie populations are in worrying decline as the region experiences dramatic warming conditions, with 5-6 degree increases in mean winter air temperatures and decreases in sea ice, a very different story appears to be evolving in the Australian territory along the east.
”We’ve found substantial increases in Adelie populations across the board over the past three decades or so – quite significant changes,” says Southwell. ”We’ve also found that new breeding colonies have been established in some places, but haven’t found anywhere that colony sites are no longer used for breeding.”
Just why the story is so different for Adelie populations on the different coasts is a question scientists are still investigating. Adelies have long been regarded as a bellwether for changing conditions, but there may be regional variations in the Adelies’ response to environmental change.
”It’s still only speculation, but in the west there is much less sea ice, and so a decline in ice with a warming climate will take it below optimal levels for Adelies,” says Southwell. Adelies are dependent on sea-ice habitats for foraging, but large areas of consolidated sea ice may limit access to the ocean and therefore limit their ability to forage.
”For the east, it could well be that there is more ice than is good for them, and so a decline in ice could – at least initially – be a good thing for Adelies.”
Southwell and his team hope to use the data coming in from the growing camera network, which gains depth and rigour with each passing season, together with older surveys and records to build a more definitive picture of changes in the Adelie populations over the past 30 years, and to then use those to explore and identify the drivers of those changes.
Elephant seals will also be the subject of some in-depth investigation this summer. Scientists are keen to find clues as to why their breeding populations on the sub-Antarctic islands of Macquarie and Kerguelen have fallen by about half over the past 50 years.
A team of researchers from the University of Tasmania is due at Davis station in February to visit the nearby elephant seal colony, where they will observe and examine the seals, hopefully collecting whisker samples – which provide clues on the seals’ diet – and fitting satellite tracking tags. Like ”penguin-cam”, these devices allow scientists to monitor hidden aspects of seal life – beaming back information on where the seals travel and forage.
Some seals are also recruited to do deep oceanographic exploration as a sideline, taking water sensors on their travels up and down the water column, and sending back information on temperature and salinity which is critical for scientists wanting to learn more about the character of deep, remote water.
Alison Dean, station leader at Davis, is already supporting another team out in the field exploring creatures at the other end of the biological spectrum – tiny little invertebrates, the most common animals in Antarctica.
”It’s a really interesting project looking at dispersal patterns of invertebrates,” says Dean. Scientists are intrigued as to how the same species might be found in Antarctic environments and in other locations – Australia and New Zealand. ”How does this happen – is it long-distance dispersal, or are the species down here living fossils? This team [of five] are out there in the field for several weeks in some really remote locations finding lots of these little creatures.”
They collect and compare the genetics of the various samples, with the Davis base providing logistics to move from site to site over the summer.
Meanwhile, over at Casey station, a fourth season of aerial survey work into the critical question of East Antarctic ice sheet dynamics – how the largest body of fresh water on Earth might behave in a warming world, arguably the greatest climate conundrum of the moment – is continuing.
Operation ICECAP – ”Investigating the Cropheric Evolution of the Central Antarctic Plate” – is a collaboration of Australian, American, British and French glaciologists. They fly close transects back and forth over the ice sheet, using various forms of radar to try to peel back the white to map the shape and form of the bedrock deep underneath.
This season the ICECAP crew is also working with NASA to collect surface information for its IceBridge project, which was set up in 2009 to straddle the gap in data collection between the end of the life of NASA’s ICESat-1 satellite and the beginning of the operational life of its successor, ICESat-2, in 2016.
The team are also doing some close survey work around the Totten Glacier, one of the largest glaciers on Earth, and one which is a hot spot for scientific interest as a result of significant change, having lowered as much as one or two metres a year in some locations.
”We’re looking at the thickness of the ice, particularly where the Totten starts to float near the grounding line, trying to get some idea of the shape and ocean cavity underneath,” says Dr Tas van Ommen, leader of the AAD’s ice core group and ICECAP collaborator.
”There’s a fair chance that what is going on is that warm water is intruding under the glacier and causing it to melt from underneath – that that’s what is causing the lowering.”
A particular focus this season was to survey the route of an old ground traverse conducted over the Totten back in 1987, and compare the thickness of the glacier recorded on that expedition with present conditions. The flight succeeded in tracking the old route to within 10 metres, collecting data that is yet to be analysed and published.
”To look at those changes over a 25-year period, we might start to get a real handle on longer-term changes. It’s important because the Totten is probably the largest change signal we see in East Antarctica, and we don’t know a lot about what’s driving it at the moment,” says van Ommen.
”The Totten Glacier is one of the larger glaciers in Antarctica in terms of the amount of mass that it drains off the continent. So even a small percentage shift in the drainage off the Totten adds quite a bit to potential sea level rise.”
Other projects scheduled for the various Australian stations this summer include ongoing programs collecting atmospheric measurements including temperatures using the LIDAR (Light Detection and Ranging) at Davis, marine science, ice core excavation to measure beryllium levels (which provides a proxy narrative on the levels of solar activity), studies of changes to Antarctic moss and seabird surveys.