Poster Annual Conference of the Genetics Society of Australasia with the NZ Society for Biochemistry & Molecular Biology

Hierarchical metapopulation structure in the southern Australia coastal bottlenose dolphin (Tursiops cf. australis) (525)

Eleanor AL Pratt 1 2 , Luciano B Beheregaray 2 , Kerstin Bilgmann 3 , Nikki Zanardo 1 2 , Fernando Diaz-Aguirre 1 2 , Luciana M Moller 1 2
  1. Cetacean Ecology, Behaviour and Evolution Laboratory, School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia
  2. Molecular Ecology Laboratory, School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia
  3. Biological Sciences, Maquarie University, Sydney, New South Wales, Australia

Little is known about the population ecology of the recently described bottlenose dolphin species Tursiops australis. The species is thought to be comprised of small and genetically distinct populations (including sub-populations under increasing anthropogenic threats) and is likely endemic to coastal southern Australia. Mitochondrial DNA (mtDNA) control region sequences and microsatellite loci were used to assess genetic variation and hierarchical population structure of coastal T. cf. australis across a range of spatial scales and environmental discontinuities between southern Western Australia (WA) and central South Australia (SA). Overall, genetic diversity was similar to that typically found for bottlenose dolphins, although very low mtDNA diversity was found in Gulf St. Vincent (GSV) dolphins. We found historical genetic subdivision and likely differences in colonisation between GSV and Spencer Gulf, outer- and inner-gulf locations, and SA/WA and previously identified Victorian/Tasmanian populations. A hierarchical metapopulation structure was revealed along southern Australia, with at least six genetic populations occurring between Esperance, WA and southern Tasmania. In addition, fine-scale genetic subdivision was observed within each SA/WA population. In general, contemporary migration was limited throughout southern Australia, but an important gene flow pathway was identified eastward along the Great Australian Bight. Management strategies that promote gene flow among populations should be implemented to assist with the maintenance of the inferred metapopulation structure. Further research into the population ecology of this species is needed to facilitate well-informed management decisions.