Southern Ocean Marine

Southern Ocean Marine
Name	Southern Ocean Marine
Location	Southern Hemisphere
Area km2	20000000
Countries	Antarctica; Argentina; Australia; Chile; New Zealand; South Africa
Major bodies	Southern Ocean; Drake Passage; Scotia Sea; Weddell Sea; Ross Sea; Amundsen Sea
Notable features	Antarctic Circumpolar Current; Antarctic Convergence; Antarctic continental shelf; Polynya; iceberg; sea ice

Contents

Southern Ocean Marine is a marine region encompassing the fringing seas, continental shelves, and pelagic environments surrounding Antarctica, including the Southern Ocean margins and adjacent sub-Antarctic islands. It is characterized by extreme seasonal variability, expansive ice cover, and unique oceanographic processes driven by the Antarctic Circumpolar Current, the Antarctic Convergence, and interactions with major ocean basins such as the Atlantic Ocean, Pacific Ocean, and Indian Ocean. Economically and scientifically significant, the region supports iconic species like Emperor penguin, Antarctic krill, Weddell seal, and Southern elephant seal, while being the focus of international governance under instruments such as the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources.

Geography and Physical Characteristics

The region includes the continental margins of Antarctica and the narrow shelves of sub-Antarctic archipelagos such as the Kerguelen Islands, South Georgia, South Orkney Islands, South Sandwich Islands, Prince Edward Islands, and Macquarie Island. Major bathymetric features include the Antarctic continental shelf, the Antarctic Slope Front, the deep basins of the Weddell Sea and Ross Sea, the tectonic structures of the Drake Passage and South Shetland Trench, and submerged plateaus like the Kerguelen Plateau and Maud Rise. The area spans numerous Exclusive Economic Zones administered by Argentina, Australia, Chile, New Zealand, and South Africa, and overlaps with protected designations under the Commission for the Conservation of Antarctic Marine Living Resources.

Ocean circulation is dominated by the Antarctic Circumpolar Current which connects the Atlantic Ocean, Pacific Ocean, and Indian Ocean and drives upwelling of Circumpolar Deep Water, Antarctic Bottom Water, and Weddell Sea Deep Water. The region experiences strong westerly winds known as the Roaring Forties and Furious Fifties that influence the Antarctic Polar Front. Seasonal sea ice dynamics are affected by interactions with the Southern Annular Mode, El Niño–Southern Oscillation, and long-term trends observed in satellite remote sensing datasets from missions like ERS-1, ERS-2, Envisat, and ICESat. Ice–ocean processes include formation of brine rejection, development of polynya systems such as the Maud Rise polynya, and iceberg calving events associated with glaciers like Pine Island Glacier, Thwaites Glacier, and the Lambert Glacier.

The marine food web is structured around primary productivity in the Antarctic Convergence and blooms of phytoplankton and microalgae that sustain large aggregations of Antarctic krill, sponges, cold-water corals, and benthic communities on the Antarctic continental shelf. Key vertebrates include Emperor penguin, Adélie penguin, Chinstrap penguin, king penguin, minke whale, fin whale, southern right whale, killer whale, Weddell seal, Crabeater seal, and Ross seal. Notable invertebrates and fishes include Antarctic silverfish, Patagonian toothfish, Euphausia superba (krill), Euphausiacea, sea spider, brittle star, and endemic benthos such as Antarctic sponges and hexactinellid sponge grounds. Habitats of conservation interest include seamounts, cold-water coral reefs like those on the Kerguelen Plateau, and unique assemblages in glacial bays such as Ronne-Filchner Ice Shelf margins.

Human presence is concentrated in research stations operated by programs from Argentina, Australia, Chile, France, Germany, India, Japan, New Zealand, Norway, Russia, United Kingdom, and United States. Commercial fisheries target species such as Patagonian toothfish and Antarctic krill, with harvesting regulated by the Commission for the Conservation of Antarctic Marine Living Resources and national administrations including Fisheries and Oceans Canada-style agencies. Historic sealing and whaling by companies like Compagnie française de la Terre Adélie and fleets from United Kingdom and Norway reshaped populations of fur seal and whale species. Shipping routes through the Drake Passage and around the Antarctic Peninsula support tourism operators licensed by organizations such as the International Association of Antarctica Tour Operators, while icebreaker operations by navies and research fleets from China, India, Russia, United States, and Australia facilitate logistics but raise concerns over biosecurity and invasive species like Mytilus galloprovincialis and Tricula montana.

Conservation governance is driven by multilateral agreements including the Antarctic Treaty System, the Convention on the Conservation of Antarctic Marine Living Resources, and provisions developed through the Commission for the Conservation of Antarctic Marine Living Resources and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) designation of Marine Protected Areas such as the Ross Sea MPA and proposed areas around East Antarctica and Weddell Sea. Regional measures involve candidate protections for the Prince Edward Islands and South Orkney Islands Southern Shelf while NGOs like BirdLife International, World Wildlife Fund, Greenpeace International, Wildfowl & Wetlands Trust, and research consortia such as the Scientific Committee on Antarctic Research advocate for biodiversity safeguards. Threats addressed include illegal, unreported and unregulated fishing, climate-driven habitat loss affecting species like Emperor penguin and Antarctic krill, and pollution from microplastics documented in studies by British Antarctic Survey, Plymouth Marine Laboratory, and Scripps Institution of Oceanography.

Category:Marine regions