Oral Presentation Leslie R. Noble1, Chrysoula Gubili1,2, Cory Robinson1, Clinton Duffy3, Geremy Cliff4, Sabine Wintner4, Mahoood Shivji5, Barry Bruce6, John Stevens6, Alison Kock7,8, Enrico Gennari9, Ryan Johnson9, Herman W. Oosthuizen10, Mike Meÿer10, Jane E. Sarginson1, Andrew P. Martin11, David W. Sims2, Catherine S. Jones1 1Institute of Biological and Environmental Sciences, Aberdeen University, Zoology Building, Tillydrone Avenue, AB24 2TZ, Aberdeen, Scotland, UK 2The Laboratory, Marine Biological Association of the United Kingdom, Citadel Hill, PL1 2PB, Plymouth, Devon, UK 3Marine Conservation Unit, Department of Conservation, Private Bag 68908 Newton, Auckland 1145, New Zealand 4KwaZulu-Natal Sharks Board, Private Bag 2, Umhlanga Rocks 4320 and Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000, South Africa 5Oceanographic Centre, Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, FL, 33004, USA 6CSIRO Marine and Atmospheric Research, GPO Box 1538, Hobart, TAS7001, Australia 7Department of Zoology, University of Cape Town, Cape Town, South Africa 8Shark Spotters, Cape Town, South Africa 9Oceans Center, Oceans Campus, Mossel Bay 6500, South Africa 10Department of Environmental Affairs and Tourism, Branch Marine and Coastal Management, Private Bag X2, Roggebaai, South Africa 11Department of Ecology and Evolutionary Biology, N122 Ramaley, University of Colorado, Boulder, Colorado 80309 Elasmobranch top predators are paramount to maintenance of marine ecosystem health, yet their recent depletions, slow life history characteristics and often widespread dispersal mark them as especially vulnerable yet difficult to protect globally. Although a species capable of long distance dispersal the natal philopatry exhibited by female white sharks (Carcharodon carcharias) further increases their vulnerability, making estimates of current population sizes and connectivity highly relevant to conservation management and protective legislation. However, knowledge of white shark population dynamics remains limited. Advances in molecular genetics and genomic analysis provide tools for objective indirect assessments of population connectivity, substructuring and dispersal. We illustrate the utility of conventional population genetic markers to conservation efforts by two studies, firstly of Mediterranean nursery stocks, which show little mitochondrial diversity and close ancestral affiliations with Pacific rather than geographically adjacent Atlantic populations. The second, by population genetic analysis of the largest widespread sample panel so far assembled, which currently affords the most highly resolved view of white shark population structure. This global phylogeographic study confirms the presence of matrilineal clades among oceans supporting the hypothesis of female philopatry and biparentally mediated gene flow. However, useful as conventional markers have been the characteristically low genetic diversity and slow evolution of sharks suggests these tools possess insufficient power to determine current population dynamics, information crucial for effective management. This has led us to employ Restriction site-Associated DNA (RAD) tag analysis of the white shark to identify highly resolving SNPs (Single Nucleotide Polymorphisms) of contemporary and historical samples to better determine contemporary population dynamics and connectivity within and outwith critically endangered populations, addressing environmental impact on genetic diversity and ecosystem sustainability.

• published: 03 May 2013
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