The dirty secret of pristine Antarctica: polluted like the port of Rio de Janeiro – of course by humans… [videos]

Antarctica is often described as one of the most pristine places in the world, but it has a dirty secret.

Parts of the seafloor near Australia’s Casey Research Station are as polluted as the harbor in Rio de Janeiro, Brazil, according to a study published in PLOS One on August 1.

Pollution is likely to be widespread at older Antarctic research stations, says study co-author Jonathan Stark, a marine ecologist at the Australian Antarctic Division in Hobart. “These pollutants accumulate over long periods of time and do not simply disappear,” he says.

Stark and his colleagues found high concentrations of hydrocarbons – compounds found in fuel – and heavy metals such as lead, copper and zinc. Many of the samples were also loaded with PCBs, highly carcinogenic chemicals that were common before an international ban in 2001.

When the researchers compared some samples with data from the Global Harbor Project — an international collaboration that monitors major urban waterways — they found that levels of lead, copper and zinc in some cases were similar to those seen in the Sydney and Rio de Janeiro harbor areas in the past two decades.

Widespread pollution

Seasha Poirot, New Zealand Antarctica’s policy, environment and safety manager in Christchurch, says the pollution problem is not unique to Casey Station. “All national programs address this issue,” he says. At New Zealand’s Scott Base – which is undergoing reconstruction – contamination left over from previous fuel spills and poor waste management was found in soil and marine sediments. Poirot says more of this historic pollution will appear as the climate warms. “Things that were once frozen in the ground are now more mobile,” he says.

Most pollution in Antarctica is due to historical poor waste management. In the past, waste was often dumped a short distance from research stations, says Terrence Palmer, a marine scientist at Texas A&M University-Corpus Christi.

Research stations got serious about cleaning up their act in 1991. That year, an international agreement known as the Environmental Protection Protocol to the Antarctic Treaty, or Madrid Protocol, was adopted. This classified Antarctica as a “nature reserve dedicated to peace and science” and instructed countries to monitor the environmental impacts associated with its activities. But much of the damage has already been done: about two-thirds of Antarctic research stations were built before 1991.

100 research stations

Although historical pollution is a problem, future pollution remains a concern as the frozen continent becomes more populated. There are already more than 100 national research stations or facilities, and most of the buildings are located in ice-free areas where they blend with wildlife to create a base on more sustainable land. Ice-free areas make up less than 1% of Antarctica’s area, but support the greatest diversity of plants and animals, including penguin and seal colonies.

A 2019 study found that more than half of the ice-free areas on the coast have land disturbance that can be seen from space. “The stations have a large footprint relative to the number of people there,” says Sean Brooks, a conservation scientist at the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Hobart, who co-authored the study.

Each country is responsible for its own environmental monitoring around research stations, and practices vary, Brooks says. He and his colleagues proposed a solution in a third preprint published in the Social Science Research Network last month. They describe a nine-step process to help station managers set goals to reduce the impact of their facilities on nearby ecosystems.

Other researchers are working to find ways to reverse the damage caused by past practices. Lucas Martinez Alvarez, a bioremediation specialist at the Argentine Antarctic Institute in Buenos Aires, and his colleagues are using bacteria to remove hydrocarbons from the soil surrounding Argentina’s Carlini Base on King George Island.

In 2020, Martinez Alvarez and his team4 reported that they were able to remove more than 75% of hydrocarbons from soil contaminated with the fuel. This approach could reduce the need to ship tons of contaminated soil from Antarctica, Martinez Alvarez says.

Stark says the Australian Antarctic Division has already begun upgrading wastewater treatment facilities at Casey and Davis stations. The next step for Stark and his colleagues is to evaluate whether historical pollution is still affecting Antarctic ecosystems today.

Stark’s previous studies have shown that polluted areas in Antarctica are less biodiverse than controlled areas, with some resistant species becoming more dominant. “It will be interesting to see whether these effects have persisted—or worsened—or whether societies have adapted in any way,” Stark says.

With information from Nature.com

Who and why argues that Joan of Arc was not quite the saint we know her to be: life, deeds, betrayal, show trial, and execution at the hands of the English [videos]

Follow Hellas Journal on Google News