Short-finned pilot whale phylogeography and stock structure

August 9, 2013

Principal Investigator: Amy Van Cise, Marine Mammal Genetics Group

Currently, two stocks of short-finned pilot whales are recognized in U.S. waters, in the eastern North Pacific and the Hawaiian Islands. The major anthropogenic threat to the animals in these areas is entanglement in fishing gear. These two stocks are thought to be of the same species, but recent evidence suggests that a subspecies or species-level distinction may exist in the Pacific Ocean (Kasuya et al. 1988; Oremus et al. 2009). Short-finned pilot whales in the Eastern Tropical Pacific face a similar threat to those in the Hawaiian Islands and eastern North Pacific, yet their phylogenetic status is also unknown. These animals are abundant in the ETP (N = 160,200) and common in the Hawaiian Islands (N = 8,806), but very rare in the eastern North Pacific (N = 304). If the stocks are genetically different, they may require different levels of management under conservation policy. Moreover, in the Hawaiian Islands it is possible that two or more distinct populations may exist, although the mechanism by which these populations have formed is currently unknown.

We aim to determine the phylogeographic status of these stocks, and further inform the possibility of a subspecies or species-level distinction amongst short-finned pilot whales in the Pacific Ocean. Continued research in focusing in the Hawaiian Islands will allow us to determine whether a higher degree of population substructure exists in these islands, and examine how relatedness and social structure affects population structure in short-finned pilot whales.

Last modified: 2/2/2015