The Southern Ocean has the lowest densities of floating macroplastic litter in the world. It was thought that the region was relatively free of microplastic contamination. However, recent studies and citizen science projects have reported microplastics in deep-sea and shallow sediments and surface waters. Microplastics have been shown, in both laboratory experiments and field-based studies elsewhere in the world, to negatively impact a range of marine species including pelagic and benthic organisms. After reviewing available information on microplastics (including macroplastics as a source of microplastics) in the Southern Ocean, we present estimated microplastic concentrations, and identify potential sources and routes of transmission into the region. Estimates suggest that the amounts of microplastic pollution released into the region from ships and scientific research stations are likely to be negligible at the scale of the Southern Ocean, but may be significant on a local scale. Furthermore, predictions of microplastic concentrations from local sources are several orders of magnitude lower than levels reported in published sampling surveys. Sea surface transfer from lower latitudes is a likely contributor to Southern Ocean plastic concentrations.
Thanks to improved analytical techniques chemicals used in personal care and pharmaceutical products are now amongst the most commonly detected compounds in surface waters worldwide. Collectively referred to as micropollutants, they include pharmaceuticals and ingredients from cosmetics, toothpastes, sunscreen, skin moisturisers, shampoos, analgesics and even recreational drugs. Micropollutants enter the aquatic environment predominantly via wastewater because conventional sewage treatment methods cannot completely remove them before the effluent is discharged. To date there have been only limited assessments on their presence and impacts in coastal environments. Experiments have shown that some of them can accumulate in sediments and biota and have endocrine disrupting effects on aquatic organisms. Micropollutants have been detected for the first time in Antarctica, in effluent from Scott Base, McMurdo Station and Mario Zucchelli Station, the surrounding sea water and sea ice, as well as in benthos, at similar concentrations to temperate coastal waters. Recent work around the Antarctic Peninsula has now found traces of fragrances, analgesics and anti-inflammatories in aquatic systems.
Antarctic soils are particularly vulnerable to disturbance due to their biological and physical properties and naturally slow recovery rates that are suppressed by low temperatures and sometimes low moisture availability. As most human activities are concentrated in relatively small scattered ice-free areas, the potential for adverse human impacts is great. Antarctic soils provide habitat for fauna and flora which are regionally important and, in some cases, include endemic representatives. Thus, protection of this component of the ecosystem should be a priority. Human trampling and track formation as a result of field camp installation, scientific activities and tourism can produce some undesirable consequences on soils. These impacts affect soil physicochemical and biological properties at different scales, ranging from populations to communities, and even habitats. The longevity of disturbances depends on soil type, regional climate, impact severity, remediation effort (if any), and what components of the ecosystem are being affected. In some cases, impacts continue decades after disturbance. Scientists have analysed these impacts, soil vulnerability and recoverability, and guidelines have been proposed to minimize the consequences of human pressures on soil environments.
Geothermal environments in Antarctica have profound ecological and scientific value. They are single points of heat and moisture in an icy and dry landscape, and provide habitats for diverse living organisms, some of which are found nowhere else on Earth. They may have provided refuges through repeated glacial cycles for diverse moss and invertebrate communities, crucially stabilizing populations in non-geothermal sites over long time periods. The unique features of these sites render them easily impacted, with physical damage and foreign biological contamination being the principal concerns. To address the need to manage activities that impact terrestrial geothermal environments in Antarctica, a Code of Conduct has been developed by SCAR and endorsed by Antarctic Treaty Parties.
The Emperor Penguin (Aptenodytes forsteri) is uniquely adapted to breed in the Antarctic winter, mainly on stable sea-ice. Climate change may negatively impact the species by changing the extent, formation and persistence of sea-ice. However, many factors may influence Emperor Penguin population success, and different colonies in different areas can have opposing population changes. The current published evidence indicates that understanding of the influence of climate change on Emperor Penguin populations is not yet fully developed. At present, following the Intergovernmental Panel on Climate Change (IPCC) guidance on descriptions of uncertainty, the available evidence can be considered limited to medium, but with high agreement. Thus, negative climate change-related impacts on the Emperor Penguin can be considered likely.
Robust evidence highlights major shifts in the abundance and distribution of penguins (Adélie, chinstrap, gentoo, emperor, king, and macaroni) breeding on the Antarctic Peninsula and across the Scotia Arc in the FAO statistical SubAreas commonly used by CCAMLR (see Figure 1). In SubArea 48.1, Adélies and chinstraps have declined throughout most of the western Antarctic Peninsula (WAP) to the north of Marguerite Bay. Adélies are stable or increasing in Marguerite Bay and to the south, and stable or increasing in the eastern Antarctic Peninsula. By contrast, gentoos on the WAP (48.1) and at the South Orkney Islands (48.2) are increasing and expanding their breeding range southwards; elsewhere, their populations are highly variable but not trending significantly. In SubArea 48.3, macaronis have experienced substantial declines while kings have increased. In SubArea 48.4, chinstraps and Adélies are stable. These findings highlight considerable spatial heterogeneity in species trends, and the importance of comparative work both to assess the drivers of population change and to predict and monitor future trends.