Fin whale (Balaenoptera physalus) off Lāna‘i, December 7, 2012
Our first fin whale sighting in the Hawaiian Islands wasn’t until December 2012, when we were able to return to Lāna‘i for the first time since 2003. This was also our first encounter with a species of baleen whale other than humpbacks in 13 years of research in Hawai‘i. Since the early 1800s whalers in Hawai‘i had recorded many “finback” whales, which could refer to fin whales, sei whales, or Bryde’s whales all of which have large dorsal fins. In this first encounter were able to collect a skin biopsy sample to confirm the species through genetic analysis, though fin whales can be positively identified by the asymmetrical coloration of their lower jaw (dark on left side and white on right).
Our second fin whale encounter, a pair of adults on February 12, 2015
Fin whales are the second largest of the baleen whales, sometimes close to 24m long, only slightly shorter in length than the blue whale. There have been more documented sightings of fin whales than blue whales in Hawaiian waters. Fin whales have been sighted off the Northwestern Hawaiian Islands during the 2002 and 2010 NMFS surveys, as well as around the main Hawaiian Islands.
Fin whales appear to be mostly absent in equatorial waters roughly between 20° N and 20° S in the Pacific. A pair of individuals was seen off Kona in January 2015, marking one of the southernmost sightings of fin whales in the central North Pacific. They appear to use Hawaiian waters primarily in winter, though they have been detected through acoustics in ten months out of the year (excluding June and July).
Fin whales in the North Pacific were a target species for whaling during the twentieth century, with more than seventy-five thousand fin whales killed in commercial whaling operations. Summer and fall abundance estimates from the 2010 NMFS survey was 154 individuals, but that number should be higher in the winter. There is evidence of a somewhat steady recovery of fin whales off the west coast of North America in the last twenty years, though nothing is known about population trends for this species. There has been an increase in fin whales in Alaskan waters, which suggests an increase in Hawaiian waters as well.
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Updated November 2021.