Worldwide population structure in Cuvier's beaked whales: identification of units for conservation

Small bone samples from over 500 Cuvier's beaked whales (Ziphius cavirostris) representing populations worldwide were collected from museums and other institutions. Genetic analysis of mitochondrial DNA (mtDNA) control region and cytochrome b diversity is underway. These data will be used for a robust statistical assessment of genetic differentiation between populations at regional and ocean basin levels and estimation of rates of dispersal, allowing units for conservation to be identified. Information on the mtDNA haplotype and sex of each specimen will also be provided. Preliminary median-spanning network reconstructions and analyses of molecular variance (AMOVA) for a subset of samples (control region--317 base pairs, n = 219; cytochrome b--326 base pairs, n = 190) revealed strong differentiation among the three ocean basins (North Atlantic, North Pacific, and Southern Hemisphere) at the haplotype and nucleotide level (p < 0.0001). There is also possible evidence of historical movements of these whales between the Atlantic and Pacific Oceans prior to the closure of the Isthmus of Panama approximately 3 million years ago. DNA extraction and sequencing are ongoing. The final deliverables for these contracts are expected in approximately 6 months' time.JG133F05SE6342, JG133F07SE2186