To assess movements relative to stock boundaries and the long-line fishery exclusion boundary, satellite tags were remotely deployed on 11 false killer whales in Hawaiian waters in
2007 and 2008, 10 on individuals from the insular population and one on an individual from the offshore population. The offshore individual, tagged 123.8 km west of the island of Hawai‘i, moved as close as 62 km from the island, inshore of the long-line fishery exclusion boundary. Individuals from the insular population moved as far as 83.1 and 95.9 km offshore, indicating the two populations overlap in terms of distance from shore, and that individuals from the insular population may overlap with the long-line fishery. Although tagged off the leeward (west) side of the island of Hawai‘i, individuals from the insular population regularly moved to the windward (east) sides of the islands. One insular individual moved extensively, ranging among the main Hawaiian Islands as far as Kaua‘i over a 32-day period, while other individuals remained associated with the island of Hawai‘i for periods greater than 45 days before moving extensively among the islands. Comparisons of distances between individuals tagged on the same day over subsequent days indicated that individuals within groups frequently disassociated and re-associated, occasionally moving greater than 100 km apart before re-associating. Individuals repeatedly used an area where large groups of false killer whales were documented from aerial surveys in 1989, lending support to the supposition that those individuals were part of the insular population.
Citation:
Baird, R.W., G.S. Schorr, D.L. Webster, D.J. McSweeney, M.B. Hanson, and R.D. Andrews. 2008. Movements of Satellite-Tagged False Killer Whales Around the Main Hawaiian Islands. Document PSRG-2008-13 submitted to the Pacific Scientific Review Group, Kihei, HI, November 2008.
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