The Southern ocean The Southern Ocean has the unique distinction of being alarge circumpolar body of water totally encircling thecontinent of Antarctica; this ring of water lies between 60degrees south latitude and the coast of Antarctica andencompasses 360 degrees of longitude 20.327 million sq km - slightly more than twice the size ofthe US Coastline - 17,968 km The Southern Ocean is deep, 4,000 to 5,000 m over mostof its extent with only limited areas of shallow water;Much is deep seafloor with generally unknown fauna. he Antarctic continental shelf is generally narrow andunusually deep, its edge lying at depths of 400 to 800 m(the global mean is 133 m) Continental shelf is unusually deep due to isostaticdepression and ice scour. The Antarctic icepack grows from an average minimumof 2.6 million sq km in March to about 18.8 million sq km inSeptember, better than a sixfold increase in area
Benthic Ecology of the Antartic A critical feature: absence ofdurophagous predators – fish anddecapod – no brachyuran crabs, lobsters,sharks, or rays, low diversity of skates, andonly 2 common clades of teleosteans(nototheniods and liparids).
Wedell seals eat mostly freeswimming prey – noequivalent to the walrus orgray whales of the Arctic. Functionally Paleozoic withslow moving invertebrate toppredators including asteroidsand nemerteans And dense and large areas ofepifaunal suspension feederspopulations. Functionally archaic does notmean the organisms are notas evolved.
Bentos gemeinschaftAntarctic sponges and ascidians from the sea floor during the current 29th Antarctic expedition of RV Polarstern East of theWestantarctic Peninsula. Photo: Julian Gutt/Dieter Piepenburg, Alfred-Wegener-Institut/IP…ÖA paradise for animals. The dense biotic community of Antarctic sponges creates habitats for diverse other fauna.Photo: A. Starmans, W. Dimmler; Alfred-Wegener-Institut
REFERENCES Alfred Wegener Institut fuer Polar undMeeresforschunghttp://www.awi.de/en/news/images_video_audio/image_galleries/picture_gallery_antarctic_benthos/ Ice shelf picture:http://www.swisseduc.ch/glaciers/earth_icy_planet/glaciers08- en.html?id=5) http://animals.nationalgeographic.com/animals/mammals/weddell-seal/ Wikipedia -http://en.wikipedia.org/wiki/Antarctic