Antarctic cleanup measures assessed and penguin habits scrutinised

Permeable reactive barrier in trench
Permeable reactive barrier in trench (Photo: John Rayner)
Adelie penguin and chickAdelie penguins and chick creche

12 October 2006

Australia's summer season of Antarctic science gets underway today with the departure from Hobart of the research vessel Aurora Australis, taking 115 expeditioners south for the busy months ahead.

The Minister for the Environment and Heritage Senator Ian Campbell said that two of the more significant projects this year were remediation of contaminated sites, and technological advances for monitoring penguins foraging for krill, and what impact future harvesting of the tiny crustacean might have on penguins.

Human Impacts in Antarctica

Senator Campbell said that this year researchers would assess the effectiveness of a permeable reactive barrier installed last summer to help trap diesel spilt at Casey in 1999 that continues to leach into a nearby melt lake and, eventually, the ocean during the ice melt in summer.

"We are hopeful that this type of barrier will prove an efficient way to help clean up errors of the past which occurred at most stations around the Antarctic continent and which happened before we understood the impact of these contaminants on the environment.

"Australia is the only nation doing this kind of work in Antarctica and other nations with a presence there are watching closely to measure its success with a view to potential implementation.

"The Australian Antarctic Division (AAD) played a pivotal role in the establishment, in 1991, of the Madrid Protocol which provides protection of the Antarctic environment."

Dr Martin Riddle, head of the AAD's Impact of Human Activities in Antarctica programme, said that the permeable reactive barrier would be trialled over the next five to eight years for its ability to remove the fuel and slow its flow.

"The barrier was built by digging a trench (5.5m wide, 2m long and 1m deep) in the path of the polluted melt water, with wings on either side to funnel the water into the trench. The trench was then filled with metal pallets containing three different layers of permeable, reactive materials.

"The first layer contains nutrients which, when mixed with water, stimulate naturally occurring microbes that will do the hard work of digesting the diesel hydrocarbons.

"The second layer contains a reactive material that captures the hydrocarbons and holds them long enough for the microbes to break them down into harmless by-products – water and carbon dioxide. The third layer catches any excess nutrients before the filtered water passes back out into the soil," Dr Riddle said.

"Work this season will be looking to measure how effectively the barrier is working and whether the chemical processes are happening as we expect.

"We will also be measuring fuel concentrations in some of the soil that was removed, and sorted in containers, during the installation of the barrier. This soil had nutrients added to enhance bioremediation," Dr Riddle said.

Adélie penguin monitoring to benefit from enhanced technology

Senator Campbell said that as large consumers of krill, Adélie penguins are useful indicators of effects of changes in krill abundance brought about by harvesting.

"Sixteen years ago the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) established an international programme to monitor the impact of the krill fishery on the Southern Ocean ecosystem and assist in sustainable management.

"In 1990, Australia established an Adélie penguin monitoring programme at Béchervaise Island near Mawson station to study the effects of krill abundance on penguins and collect baseline data in the event of a krill fishery opening up in the region," Senator Campbell said.

Recently, the Australian Antarctic Division (AAD) has developed an automated camera, powered by solar panels, to monitor aspects of Adélie chick survival and breeding chronology.

AAD ecologist Dr Matt Low who sails for Antarctica today said that during the winter months the cameras 'sleep' then 'awaken' as the summer returns to record a series of photographs throughout the breeding season.

"This year, we will install six cameras at new island sites in the Mawson region. This will give us access to information over a much broader area than if we concentrated solely on Béchervaise.

Dr Low said that the latest development will build on data collected so far in this long-running programme to give a more comprehensive picture.

"An automated recording system in place since 1991 already logs the birds automatically as they enter and leave the colony.

"Many of the birds can be individually identified by microchips implanted under the skin. These are detected via an antenna near the colony. Two infra-red beams, which are cut sequentially by the birds as they pass by, tell us the time of passing and direction of travel.

"This information tells us about the length of time birds have been foraging at sea.

"Now, extra monitoring from the cameras will give us substantial boost towards a broader understanding of the needs of the penguins in this study," Dr Low said.

One major aim of CCAMLR is to ensure that the human harvest of krill does not adversely affect any element of the Southern Ocean Antarctic marine ecosystem.

Aurora Australia departs Hobart on Thursday 12 October at 4 pm.