Antarctic patterns of shallow subtidal habitat and inhabitants in Wilke’s Land

• Main Authors: Johnston, Emma L., Connell, Sean D., Irving, Andrew D., Pile, Adele J., Gillanders, Bronwyn M., 1963-
• Format: Article in Journal/Newspaper
• Language: English
• Published: Germany : Springer 2007
• Subjects: Pure basic research; 960306 Effects of Climate Change and Variability on Antarctic and Sub-Antarctic Environments (excl. Social Impacts); 960502 Ecosystem Assessment and Management of Antarctic and Sub-Antarctic Environments; 960802 Coastal and Estuarine Flora; Fauna and Biodiversity; 050206 Environmental Monitoring; 050102 Ecosystem Function; 050104 Landscape Ecology; Antarctica > Macroalgae > Benthic community; Journal Article. Refereed; Scholarly Journal; Antarctic; Austral; Coast Island; Windmill Islands; Antarc*; Antarctica; Polar Biology; Sea ice
• Online Access: http://hdl.cqu.edu.au/10018/1034541

Studies of east Antarctic marine assemblageson hard substrata are rare. In relation to sea-ice breakout, we assessed benthic patterns of habitat and inhabitants between islands and bays at each of two depths (6 and 12 m) across the Windmill Islands coast. Island sites experience sea-ice breakout in the austral spring, while bay sites typically retain sea-ice cover into the summer and in some places the cover is virtually permanent. Composition of assemblages differed between sheltered bays and exposed islands. Islands were dominated by macroalgae, which also varied with depth. Immediately below the ice–foot zone at 6 m, substratum space were monopolised by foliose red (Palmaria decipiens) and foliose brown (Desmarestia sp.) algae, whereas at 12 m large canopies of Himantothallus grandifolius was abundant. The understorey consisted of a mixture of turfs and encrusting red algae at 6 m, and coralline algae at 12 m. Sheltered bays hadl arge areas of sediment/algal complex and no canopy forming macroalgae. We found more sponges and hydroids in bays, and more brittle stars around islands. Experiments testing factors that covary with exposure and depth in Antarctica, such as light, sedimentation and ice scour are necessary to determine processes that maintain these striking patterns.