Physical controls on deep water coral communities on the George V Land slope, East Antarctica

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doi: 10.1017/S0954102010000180
Authors:Post, A.; O'Brien, P.; Beaman, R.; Riddle, M.; De Santis, L.
Main Author Affiliation:Post, A., Geoscience Australia, Marine and Coastal Environment Group, Canberra, A.C.T.
Volume Title:Antarctic Science
Source:Antarctic Science, 22(4), p.371-378. Publisher: Cambridge University Press, Cambridge, United Kingdom. ISSN: 0954-1020
Publication Date:2010
Note:In English. 31 refs. Ant. Acc. No: 89497; illus., incl. 1 table, sketch map
Abstract:Dense coral-sponge communities on the upper continental slope at 570-950 m off George V Land, East Antarctica have been identified as Vulnerable Marine Ecosystems. The challenge is now to understand their probable distribution on other parts of the Antarctic margin. We propose three main factors governing their distribution on the George V margin: 1) their depth in relation to iceberg scouring, 2) the flow of organic-rich bottom waters, and 3) their location at the head of shelf cutting canyons. Icebergs scour to 500 m in this region and the lack of such disturbance is a probable factor allowing the growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons which receive descending plumes of Antarctic Bottom Water formed on the George V Shelf, which could entrain abundant food for the benthos. The canyons harboring rich benthos are also those that cut the shelf break. Such canyons are known sites of high productivity in other areas due to strong current flow and increased mixing with shelf waters, and the abrupt, complex topography. These proposed mechanisms provide a framework for the identification of areas where there is a higher likelihood of encountering these Vulnerable Marine Ecosystems.
Index Terms:Anthozoa; Cnidaria; Communities; Continental slope; Ecology; Ecosystems; Marine environment; Nutrients; Reefs; Slope environment; Antarctica; East Antarctica; Antarctica--East Antarctica; George V Land; Invertebrata
Coordinates:S673000 S653000 E1470000 E1390000
Publication Type:journal article
Record ID:303450
Copyright Information:GeoRef, Copyright 2018 American Geosciences Institute.
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