Extraordinarily high biomass benthic community on Southern Ocean seamounts

• Published in: Scientific Reports
• Main Authors: Thresher, R. E., Adkins, J., Fallon, S. J., Gowlett-Holmes, K., Althaus, F., Williams, A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Publishing Group 2011
• Subjects: Biodiversity; Zoology; Ecology; Oceanography; Antarc*; Antarctic; Southern Ocean
• Online Access: https://doi.org/10.1038/srep00119; https://www.ncbi.nlm.nih.gov/pmc/PMC3216600

We describe a previously unknown assemblage of seamount-associated megabenthos that has by far the highest peak biomass reported in the deep-sea outside of vent communities. The assemblage was found at depths of 2–2.5 km on rocky geomorphic features off the southeast coast of Australia, in an area near the Sub-Antarctic Zone characterised by high rates of surface productivity and carbon export to the deep-ocean. These conditions, and the taxa in the assemblage, are widely distributed around the Southern mid-latitudes, suggesting the high-biomass assemblage is also likely to be widespread. The role of this assemblage in regional ecosystem and carbon dynamics and its sensitivities to anthropogenic impacts are unknown. The discovery highlights the lack of information on deep-sea biota worldwide and the potential for unanticipated impacts of deep-sea exploitation. © 2011 Nature Publishing Group. Received 03 August 2011. Accepted 03 October 2011. Published 18 October 2011. We thank E. Anagnostou, B. Barker, A. Beck, W. Cho, J. Cordell, A. Gagnon, R. Gurney, S. John, A. Kennedy, H. Kippo, M. Lewis, F. McEnnulty, N.Meckler, D. Mills,M. Sherlock, D. Staples, A. Subhas and N. Thiagarajan, and the crews of the AUV ABE, the ROV Jason and RV Thomas T. Thompson and RV Southern Surveyor for their invaluable and professional assistance in the field, P. Alderslade, S. Cairns, D. Fautin, M. Mitchel and K. Moore for taxonomic assistance, P. Brodie and J. Dowdney for assisting in the photographic analyses, T. Trull for discussion regarding the radiocarbon analyses, J. Guinotte and R. Matear for discussions on regional patterns of productivity and export, and N. Bax, F. McEnnulty and the NSR sub-editor,M. Scardi, for valuable comments on the ms. This work was supported by the U.S. National Science Foundation, the Australian Department of Environment, Water, Heritage, and the Arts, the Australian Commonwealth Environmental Research Fund Marine Biodiversity Hub, and a grant of ship time by the Australian National Research ...