Molecular genetic techniques are proving to be an invaluable tool for learning more about cetaceans. All cetaceans are difficult to study and analyses of molecular genetic markers provide insight about a species movement patterns and social structure. And this insight is particularly valuable for our studies of false killer whales and short-finned pilot whales, because, in general, there is little known about these species.
The false killer whale and short-finned pilot whale are two of the cetacean species that have been observed taken by the longline fishery that operates in the central Pacific, and using our best available data, the false killer whale has been identified as a 'strategic' stock (Nitta and Henderson, 1993; Carretta et al., 2004). Both species are largely pelagic in distribution and are found in tropical and temperate waters of all ocean basins. We have been using the mitochondrial DNA control region sequences to examine population structure. Our preliminary results show that for both species, the animals sampled around the Hawaiian Islands are separate, reproductively isolated populations and have likely been isolated from animals living in the eastern tropical Pacific for a long time. The data for short-finned pilot whales also suggest additional structure within the eastern tropical Pacific, and that neither species has a strictly matrilineal pod structure.
Chivers, S.J., R.W. Baird, D.J. McSweeney, D.L. Webster, N.M. Hedrick, and J.C. Salinas. 2007. Genetic variation and evidence for population structure in eastern North Pacific false killer whales (Pseudorca crassidens). Canadian Journal of Zoology 85:783-794.
Nitta, E. and J. R. Henderson. 1993. A review of interactions between Hawaii’s fisheries and protected species. Marine Fisheries Review 55:83-92.
Carretta, J., K. Forney, M. Muto, J. Barlow, J. Baker, B. Hanson, and M. Lowry. 2004. US Marine Mammal Stock Assessments: 2004. NOAA-TM-NMFS-SWFSC-375. 323pp.