Southern Hemisphere Blue Whale Catalogue: preliminary results of IWC comparisons between Australia, New Zealand and Sri Lanka regions
Barbara Galletti Vernazzani, Catherine R.M. Attard, Dawn R. Barlow, Chris Burton, Asha de Vos, Michael Double, Peter Gill, Curt Jenner, Micheline-Nicole Jenner, Luciana M. MÃ¶ller, Paula Olson, Chandra Salgado-Kent and Leigh G. Torres
Blue whales are known to occur off Australia, New Zealand and Sri Lanka but little is known about their long-term movements. The Southern Hemisphere Blue Whale Catalogue is a platform to share individual photo-identification catalogues among blue whale research groups. Comparisons of 698 photo-identified blue whales from seven different research groups working in the Perth Canyon (western Australia), Geographe Bay (western Australia), Bonney Upwelling (southern Australia), around New Zealand, and Sri Lanka provided eighteen whales resighted between different areas. Matches were found within Australian catalogues and within New Zealand catalogues but no matches were found between regions. Some blue whales initially sighted in the Perth Canyon, Geographe Bay and the Bonney Upwelling were subsequently resighted in any of these three regions, representing a high level of connectivity among these sites and providing support that there is one distinct population of blue whales in Australia. Recaptures within New Zealand but not between Australia and New Zealand support the suggestion of New Zealand blue whales being a separate population. No matches to Sri Lanka suggest it is a separate population or, as indicated previously, a different subspecies. Further efforts are needed to compare photo-identification catalogues from these regions with other catalogues from the eastern South Pacific and Southern Ocean to better understand population structure.