Antarctica

The Antarctic territory is claimed by seven countries, covering an area of 14 million km². France, Norway, and the United Kingdom claim sovereignty over parts of the white continent, along with neighboring nations like Argentina, Australia, Chile, and New Zealand (Antarctic Treaty, 1959).

The combined Chilean and Argentine territories occupy about 1.4 million km², an area known as West Antarctica, which is separated from East Antarctica by the 4,000 km-long Transantarctic Mountains (Libertelli, 2021).

Less than 1% of the continent is ice-free, and it has the coldest, driest, and windiest conditions on the planet, making it extremely inhospitable. This has led to unique adaptations among the organisms living there and limited terrestrial biodiversity. During the summer, when ice melts along the coast, a variety of mosses, lichens, fungi, grasses, and dicotyledons can be found, along with birds and mammals during breeding and resting periods. Marine biodiversity, on the other hand, is much richer. There are about 300 fish species in Antarctic waters, 90% of which are endemic to the region. Additionally, the Antarctic benthic community—organisms living on the sea floor—has a great diversity of species (Libertelli, 2021).

This ecosystem has experienced extreme events over the years, with the most significant one occurring in 1980 when a large part of the ozone layer was discovered to be depleted over Antarctica. This depletion was caused by the presence of chlorofluorocarbons (CFCs) in the atmosphere, which were used in refrigerants and aerosols. The effects of this "hole" in the ozone layer can still be observed in the massive increase of ultraviolet radiation during the Antarctic spring and stratospheric cooling, which have consequences for high-latitude ecosystems (southern and central-south regions of Chile and Argentina), glaciers, and precipitation patterns (Siegert et al, 2023; Barria, 2021).

Although the population in Antarctica is minimal, human activities still impact this distant ecosystem due to environmental processes, affecting ecosystem dynamics and raising concerns about microplastic pollution and other chemicals, along with potential bioaccumulation and toxicity for exposed organisms. Carbon emissions related to krill acidify the oceans, and global warming, along with the existing ozone hole, melts ice bodies, which leads to ocean stratification. Additionally, fishing activities pose a threat to Antarctic biodiversity and habitats (Grosu, 2023; Barria, 2021).