Regionalisation analyses are used to classify the environments across a region into a number of discrete classes. This helps modellers and managers to subdivide a region into spatial units, such that environmental conditions within a unit are fairly similar, and different to those of other units. The 2006 workshop on Bioregionalisation of the Southern Ocean (Grant et al. 2006) demonstrated a suitable method for Southern Ocean regionalisation analyses, and provided a circumpolar pelagic regionalisation based on four physico-chemical variables.
These analyses have recently been revisited, giving an updated pelagic regionalisation of the Southern Ocean south of 40°S, based on sea surface temperature, depth, and sea ice information. The results show a series of latitudinal bands in open ocean areas, consistent with the oceanic fronts. Around islands and continents, the spatial scale of the patterns is finer, and is driven by variations in depth and sea ice (Raymond, 2011).

Map of regionalisation results. Full size image

Properties of the region types. Full size image

The results of these analyses can be downloaded from here.

References

• Grant, S., Constable, A., Raymond, B., and Doust, S. (2006) Bioregionalisation of the Southern Ocean: Report of Experts Workshop (Hobart, September 2006). ACE-CRC and WWF Australia
• Raymond, B. (2011) A circumpolar pelagic regionalisation of the Southern Ocean. CCAMLR Workshop on Marine Protected Areas (Brest, France, 29 August to 2 September 2011). Document WS-MPA-11/6. http://data.aad.gov.au/regionalisation