Community Structure and Benthic Habitats across the George V Shelf, East Antarctica: Trends Through Space and Time

• Published in: Deep Sea Research Part II: Topical Studies in Oceanography
• Other Authors: APOST (custodian), Beaman, R.J. (author), Commonwealth of Australia (Geoscience Australia) (owner), Commonwealth of Australia (Geoscience Australia) (pointOfContact), EGD (hasAssociationWith), Eleaume, M. (author), Manager Client Services (distributor), Manager Client Services (custodian), O'Brien, P.E. (author), Post, A.L. (author), Riddle, M.J. (author)
• Format: Text
• Language: unknown
• Published: Australian Ocean Data Network
• Subjects: geoscientificInformation; External Publication; Scientific Journal Paper; Antarctic data; abiotic surrogates; continental shelf; marine biodiversity; marine; AQ; EARTH SCIENCES; Published_External; Antarctic; East Antarctica; Antarc*; Antarctica; Iceberg*
• Online Access: https://researchdata.edu.au/community-structure-benthic-space-time/682437; https://pid.geoscience.gov.au/dataset/ga/69333; https://doi.org/10.1016/j.dsr2.2010.05.020

Maintenance and Update Frequency: unknown Statement: Unknown Physical and biological characteristics of benthic communities are analysed from underwater video footage collected across the George V Shelf during the 2007/2008 CEAMARC voyage. Benthic habitats are strongly structured by physical processes operating over a range of temporal and spatial scales. Iceberg scouring recurs over timescales of years to centuries along shallower parts of the shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf, and cross-shelf flow of high salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit and filter feeding communities. Long term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are shown to be important factors in the structure of benthic communities across the George V Shelf. The modern shelf communities mapped in this study largely represent colonisation over the past 8-12ka, following retreat of the icesheet and glaciers at the end of the last glaciation (Harris et al., 2001; Ingólfsson et al., 1998). Recolonisation on this shelf may have occurred from two sources: deep-sea environments, and possible shelf refugia on the Mertz and Adélie Banks. However, any open shelf area would have been subject to intense iceberg scouring (Beaman and Harris, 2003). Understanding the timescales over which shelf communities have evolved and the physical factors which shape them, will allow better prediction of the distribution of Antarctic shelf communities and their vulnerability to change. This knowledge ...