A study conducted near an Australian station reveals significant marine pollution linked to poor waste management.
Arsenic, iron, copper, lead, cadmium, polychlorinated biphenyls and phosphate have been found in marine sediments around the Australian Casey station in Antarctica, as confirmed by a recently published twenty-year study. This pollution, generated by a waste management policy that was poorly supervised in the past, has had lasting environmental impacts in the vicinity of the station. While the study only focused on the Australian Casey station, similar conclusions could well apply to other Antarctic stations, particularly the oldest ones.
Antarctica currently features 112 research stations. More than a third of these were built before 1980, at a time when little attention was paid to the environmental impact of human activities. Waste was generally disposed of in landfills, on sea ice or directly into the ocean.
By 1990, spurred on by the Madrid Protocol, environmental management started to be considered, and waste was exported for treatment off the continent. Nevertheless, the legacy of past practices is still a legacy of environmental contamination, as shown by a study recently published in the scientific journal Plos One and focusing on the Australian Casey station. “As most stations are located in coastal areas, this can lead to contamination of local marine environments, with sources such as sewage discharges, oil spills and waste disposal sites,” says Jonathan S. Stark, researcher with the Australian Antarctic Division and lead author of the paper.
Until 1986, Casey’s solid waste was disposed of at a site in Thala Valley, on the tidal foreshore of Brown Bay. Here, batteries, empty oil and chemical drums, clothing, building materials, asbestos, cement and used oil were all dumped. In addition, oil slicks were regularly observed seeping into the bay when the ice melted in summer. An assessment carried out in 1994 had already revealed high concentrations of metals and hydrocarbons.
Clean-up operations in 1995-1996 and 2003-2004 resulted in the removal of several hundred tonnes of waste, but contaminants including polybrominated diphenyl ethers and polychlorinated biphenyls – carcinogenic substances – remained, accumulating in the marine sediments near the station.
By drilling into these sediments in search of contaminants between 1997 and 2015, researchers discovered that certain areas contained levels of pollution comparable to those found in Sydney Harbour or on the outskirts of Rio de Janeiro. The impact on wildlife is still difficult to assess, given the lack of data on the subject.
The Australian Casey Research Station was built between 1964 and 1969 on the Bailey Peninsula in southeastern Antarctica. Originally intended to replace the Wilkes station built in 1957, which had become unsafe due to fuel seepage. Casey didn’t withstand the elements much better: corrosion of the infrastructure, linked both to the building materials used at the time and their proximity to the sea, restricted its lifespan.
In the 1980s, a major rebuilding program was launched for all Australian Antarctic stations. The “Old Casey” station was dismantled and removed from Antarctica, and replaced by a new “Casey” in 1988. Built one kilometer from the old infrastructure, the Australian station, still in operation, accommodates 25 people in winter and 90 in summer.
Research stations and activities in the Antarctic have been the focus of pollution studies for some time. A recent article reported on the concentrations of microplastics in the vicinity of Scott and McMurdo stations, and on traffic routes. One source of pollution was found to be the microfibres released by the flags lining the research stations or used to mark paths, depots and dangerous spots.
However, studies on the environmental impact of research activities are lacking, as is a coordinated long-term monitoring program: “This study provides evidence to support continent-wide monitoring efforts, and to raise awareness of the potential impacts of research stations on the Antarctic environment, and inform environmental management practices,” conclude Stark and his team.
Mirjana Binggeli, PolarJournal
Link to the study : Stark JS, Johnstone GJ, King C, Raymond T, Rutter A, Stark SC, et al. (2023) Contamination of the marine environment by Antarctic research stations: Monitoring marine pollution at Casey station from 1997 to 2015. PLoS ONE 18(8): e0288485. https://doi.org/10.1371/ journal.pone.0288485
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