Overview

Fin whales (Balaenoptera physalus, Linnaeus 1758) are uncommon in Puget Sound and throughout the Salish Sea, but it is not known how often these whales used the area before commercial whaling decimated their populations worldwide. Currently, fin whale populations are recovering, and they number over 11,000 individuals along the west coast of the United States; they are still listed as Endangered under the US Endangered Species Act. As the second-largest species of animal on the planet, their occasional presence in the Salish Sea is notable, and only the future will tell if they will use these waters more regularly.

Status, trends & events

The fin whale is a rorqual whale, related to blue, minke, and humpback whales. There is little information on fin whale trends in the Salish Sea, since they are seen here so rarely. However, in 2018 the California/Oregon/Washington stock of fin whales (the likely source of whales seen in the Salish Sea) was estimated to number 11,065 individuals (CV=0.405) (Becker et al. 2020). This stock of fin whales has generally been increasing since about 1979, and during the period from 1991 to 2014 increased at a phenomenal rate of approximately 7.5% per year (Becker et al. 2020; Carretta et al., 2023).

In Washington State, fin whales are listed as Endangered, and in Canadian waters, COSEWIC lists them as Special Concern. The overall species is listed as Vulnerable globally on the IUCN Red List, and IUCN lists a population in the Mediterranean Sea as Endangered. In US waters, the species is not generally considered to be in trouble, but it is nonetheless still officially listed as Endangered under the US Endangered Species Act (Carretta et al. 2023; Muto et al. 2022).

Historically, fin whales were harvested in great numbers. Like other rorqual whales that are fast swimmers and sink when they die, fin whales were relatively safe from commercial whaling that occurred through the end of the nineteenth century.  Those traditional whalers, mostly using sail-powered vessels, and hunting by hand-thrown harpoons from small boats, simply could not effectively catch and process rorquals. That changed at the end of 1800s, with the invention of steam-powered catcher boats, guns that shot exploding harpoon heads, and factory ships with stern slipways that could process whales at sea. Blue whales (Balaenoptera musculus), the largest species, were the first to be decimated by this new technology and fin whales were the next major target of these whalers. From the 1930s-1960s, whalers killed tens of thousands of fin whales in the North Pacific, and up to 750,000 in the Southern Hemisphere. Global stocks plummeted, although never as badly as did those of the blue whale.

Whaling occurred throughout the globe, and there were several American and Canadian whaling stations that operated in the Salish Sea (Webb 1988; Goddard 1997). Fin whales were hunted mainly for their oil, but baleen and meat were also products of some commercial value.  In southern British Columbia, there were whaling stations at Mill Bay and Pages Lagoon, both on Vancouver Island, and at Jericho Bay and Pasley Island, on the mainland (Goddard 1997). Specific numbers of fin whales taken by these stations are hard to come by, but to give some idea of the magnitude of the kill, the whaling station at Bay’s City, near Gray’s Harbor, Washington, reportedly took 602 fin whales between 1911 and 1925 (Scheffer and Slipp 1948).  The main whaling season was from April through September. Several whaling stations in British Columbia (outside of the Salish Sea) killed 5,578 fin whales between the years of 1905 and 1967 (Pike and MacAskie 1969). Very small numbers of fin whales were also killed by native whalers in BC and Washington, for instance by the Makah tribe off the Olympic Peninsula.

Natural history

Fin whales are one of the most abundant baleen whales on Earth, and the current global population is likely well over 145,000 individuals, with the North Atlantic and North Pacific each having over 50,000 (Cooke 2018).  They are increasing in most areas, as populations recover from heavy exploitation by commercial whalers in the 1900s.

Fin whales inhabit deep, oceanic waters, but also can be seen near shore in some regions. They have an extensive global range that covers most marine waters from the tropics to high-latitude areas. Only a few enclosed seas (e.g., Baltic Sea, Black Sea, Gulf of Mexico, Persian Gulf, Red Sea, Salish Sea) are not normally inhabited, though occasional strays may show up in those places. While they can also be found in tropical waters, they are generally not common there, and their main area of occupancy is the temperate and subpolar zones. Interestingly, temperate populations migrate between warmer waters for mating and calving, and colder waters for feeding (Aguilar and Garcia-Vernet 2018).

While fin whales may once have been seen, at least occasionally, in the inshore waters of the Salish Sea, they are currently relatively rare in these waters (Calambokidis and Baird 1994). Scammon (1874) reported “finback” whales to be common in the Strait of Georgia and Strait of Juan de Fuca in the mid-1800s, but there is some question as to his possibly confusing minke (Balaenoptera acutorostrata) and fin whales. The pre-whaling range of fin whales off British Columbia was likely mostly offshore, according to habitat modeling studies (Gregr and Trites 2001). Sightings today are considered most likely to occur in the Strait of Juan de Fuca, which is closest to their migration route on the outer coast (Everitt et al. 1979). At least 14 sightings of four different fin whales have been photographically documented in inland waters in the past decade – one sighting of one individual in the Strait of Juan de Fuca in 2015; nine sightings of one individual in the Strait of Juan de Fuca, near Port Angeles, and in southern Puget Sound in 2016; one individual sighted near Victoria, BC, in 2019; and one individual sighted three times in central Puget Sound in 2022, which was later found dead in the inland waters of British Columbia (Erin Falcone, Marine Ecology & Telemetry Research, pers. comm.). These sightings seem to suggest that fin whales are using inland waters more than in the past.

Fin whales feed on small prey that gather in large aggregations, such as krill, copepods, and other small invertebrates, as well as schooling fishes, like capelin (Mallotus villosus), herring (Clupea pallasii), sand lance (Ammodytes hexapterus), mackerel (Scomber japonicus), and blue whiting (Micromesistius poutassou). They are batch feeders, using a lunging technique to take in huge mouthfuls of water and prey, assisted by the long pleats on their throats, which allow the distension of their mouths, greatly increasing the amount of food to be taken in. They then expel the water, and the prey are trapped on the fringes of the baleen plates inside their upper jaws (baleen are the plates of keratinous tissue hanging from their upper jaws).

Biology

The fin whale is the second-largest species of whale, and probably also the second-largest animal to have ever lived on this planet. Although they get larger in the Antarctic, Northern Hemisphere fin whales rarely reach lengths of over 24 m. Large fin whales can be as heavy as 120,000 kg, and females grow larger than males. Length at birth is around 6-6.5 m. The blow of a fin whale is tall and slender, reaching up to 4-6 m in height. Although they look quite similar to other large rorqual whales, the unique color pattern components (especially the asymmetrical lower jaw – right side white, left side gray/black) and prominent dorsal fin with a very shallow leading edge are diagnostic (see Jefferson et al. 2015).

Fin whales are fast swimmers, a characteristic which helped to keep them safe from whalers for some time (see Status and Trends). After a series of blows (also called spouts), fin whales will often submerge on a deeper, longer dive, but almost never throw their flukes up into the air the way blue whales usually do. Most fin whale populations have an annual migration cycle, which takes them from their winter breeding grounds in warmer, subtropical waters to their summer feeding grounds in higher-latitude regions of both hemispheres. When they are feeding, they often lunge sideways along the surface to engulf great quantities of prey, and this “lunge feeding” behavior is spectacular to observe.

A distinctive 20-Hz whale call has now been ascribed to fin whales, and it is thought that this may be used by males in breeding displays, similar to humpback whale song (Schevill et al. 1964). Mating and calving occur in subtropical areas that are not as distinct and predictable as those of humpback, right, or gray whales. Fin whales can live to be 80-90 years of age, and sexual maturity occurs at 6-10 years for males and 7-12 for females. Gestation lasts 11-12 months. Mating and the birth of a calf have not been observed clearly, but this is not surprising for an animal that lives nearly all its life underwater and has not been held in captivity.

Killer whales (Orcinus orca) are most certainly their main predator, though large sharks may sometimes pose a threat as well. Fin whales, like other rorqual whales (except the humpback, Megaptera novaengliae) appear to have a relatively simple social system and tend to be rather solitary outside the mother/calf pair bond. Multiple fin whales may come together on productive feeding grounds, but these usually appear to be opportunistic aggregations, with little long-term integrity. It is not known how fin whales use the Salish Sea, but most likely they come to the area searching for suitable patches of prey.

Fin whales are no longer hunted along the west coast of North America, but in the twentieth century they were heavily exploited in this area, leading to a decline in population size (see Status and Trends). Threats to fin whales in the North Pacific currently include entanglement and mortality in California large-mesh drift gillnets, longlines, and occasionally other fishing gear, as well as potential disturbance from naval sonar and shipping noise (Carretta et al. 2023). The major anthropogenic threat is probably strikes by vessels, which are often fatal and the major mortality factor seen in the Salsih Sea. Estimated vessel strike mortality is 43 animals per year (Carretta et al. 2023).

Most stranded or dead fin whales in the Salish Sea appear to have been hit by large vessels, and sometimes the animal’s carcass may have been carried long distances on the vessel’s bow (Douglas et al. 2008). There have been seven such cases in recent years (one in Tacoma in 1986; three in Seattle, Ferndale, and Sucia in 2002; two in Lummi Bay and Everett in 2006; and one near the Strait of Juan de Fuca in 2017 – see Douglas et al. 2008 and the Cascadia Research Collective). Sightings are more rare but may be increasing in frequency. There was a sighting off Minor Island in September 2015, and another off the Jordan River, BC, in July 2016. One was seen in September 2019, near Sequim by a whale-watching vessel. Another fin whale was sighted several times in 2021 near Golden Gardens Park, north of Seattle, and the most recent one appears to be a whale sighted repeatedly January 9-16, 2022, foraging north of Seattle (additional sources in KIRO 7 News and Puget Sound Express).

Fin whales are reasonably well studied in waters along the outer coast of North America and in the Gulf of California, Mexico, but specific studies on the species in the Salish Sea are very few. For this reason, there is not much known about the ecology of fin whales in Salish Sea or Puget Sound waters.

Data sources & gaps

Most status information in this report comes from Carretta et al. (2023).  While some monitoring and information gaps for this species exist, there is generally adequate information to determine the status and trends of this species along the west coast. Information specific to the Salish Sea or Puget Sound, however, is largely lacking.

Methods & statistics

Methods of determining the population status of the California/Oregon/Washington stock of fin whales mostly comes from vessel-based line-transect analysis, habitat-based species distribution modeling, and Bayesian trend analysis (see Carretta et al., 2023).

References

Aguilar, A. & R. Garcia-Vernet. (2018). Fin whale Balaenoptera physalus.  In Würsig, B., J. G. M. Thewissen & K. M. Kovacs. Encyclopedia of Marine Mammals (Third Edition). Pages 368-371. Academic Press.

Becker, E. A., K. A. Forney, D. L. Miller, P. C. Fiedler & J. Barlow & J. E. Moore. (2020). Habitat-based density estimates for cetaceans in the California Current Ecosystem based on 1991-2018 survey data. NOAA Technical Memorandum NMFS-SWFSC-638. ix + 69pp.

Calambokidis, J. & R. W. Baird. (1994). Status of marine mammals in the Strait of Georgia, Puget Sound and the Juan de Fuca Strait and potential human impacts. In R. C. H. Wilson, R. J. Beamish, F. Aitkens & J. Bell (Eds.), Review of the marine environment and biota of Strait of Georgia, Puget Sound and Juan de Fuca Strait. (pp. 282-303). Canadian Technical Report of Fisheries and Aquatic Sciences.

Carretta, J. V., E. M. Oleson, K. A. Forney, D. W. Weller, A. R. Lang, J. Baker, A. J. Orr, B. Hanson, J. Barlow, J. E. Moore, M. Wallen & R. L. Brownell Jr. (2023). U.S. Pacific marine mammal stock assessments: 2022. NOAA Technical Memorandum NMFS-SWFSC, 684, 404 pp.

Cooke, J.G. (2018). Balaenoptera physalus. The IUCN Red List of Threatened Species 2018: e.T2478A50349982. Accessed on 18 June 2024.

Douglas, A. B., J. Calambokidis, S. Raverty, S. J. Jeffries, D. M. Lambourn & S. A. Norman. (2008). Incidence of ship strikes of large whales in Washington State. Journal of the Marine Biological Association of the United Kingdom, 88, 1121-1132.

Everitt, R. D., C. H. Fiscus & R. L. Delong. (1979). Marine mammals of northern Puget Sound and the Straits of Juan de Fuca. NOAA Technical Memorandum ERL-MESA, 41, 141 pp.

Jefferson, T. A., M. A. Webber & R. L. Pitman. (2015). Marine Mammals of the World: A Comprehensive Guide to Their Identification. Academic Press/Elsevier.

Goddard, J. (1997). A Window on Whaling in British Columbia. Desktop Publishing, Inc.

Gregr, E. J. & A. W. Trites. (2001). Predictions of critical habitat for five whale species in the waters of coastal British Columbia. Canadian Journal of Fisheries and Aquatic Sciences, 58, 1265-1285.

Muto, M. M., B. J. D. V. T. Helker, N. C. Young, J. C. Freed, R. P. Angliss, N. A. Friday, P. L. Boveng, J. M. Breiwick, B. M. Brost, M. F. Cameron, P. J. Clapham, J. L. Crance, S. P. Dahle, M. E. Dahlheim, B. S. Fadely, M. C. Ferguson, L. W. Fritz, K. T. Goetz, R. C. Hobbs, Y. V. Ivashchenko, A. S. Kennedy, J. M. London, S. A. Mizroch, R. R. Ream, E. L. Richmond,K. E. W. Shelden, K. L. Sweeney, R. G. Towell, P. R. Wade, J. M. Waite, & A. N. Zerbini. (2022). Alaska marine mammal stock assessments, 2021. NOAA Technical Memorandum, NMFS-AFSC-441, 295 pp.

Pike, G. C. & I. B. MacAskie. (1969). Marine mammals of British Columbia. Bulletin of the Fisheries Research Board of Canada, 171, 54 pp.

Scheffer, V. B. & J. W. Slipp. (1948). The whales and dolphins of Washington State, with a key to the cetaceans of the west coast of North America. American Midland Naturalist, 39, 257-337.

Schevill, W. E., W. A. Watkins & R. H. Backus. (1964). The 20-cycle signals and Balaenoptera (fin whales). In W. N. Tavolga (Eds.), Marine Bio-Acoustics. (pp. 147-152). Pergamon Press, Oxford.

Webb, R. L. (1988). On the Northwest. Commercial Whaling in the Pacific Northwest 1790-1967. University of British Columbia Press, Vancouver.

Additional links

Caretta, James V, et al. DRAFT U.S. Pacific marine mammal stock assessments: 2023. NOAA Technical Memorandum NMFS-SWFSC-XXX. https://www.fisheries.noaa.gov/s3/2024-01/Draft-2023-Pacific-MMSARs.pdf

Fin whale (Balaenoptera physalus). Washington Department of Fish and Wildlife. https://wdfw.wa.gov/species-habitats/species/balaenoptera-physalus

COSEWIC Assessment and Status Report on the Fin Whale Balaenoptera physalus. Environment and Climate Change Canada. https://wildlife-species.canada.ca/species-risk-registry/virtual_sara/files/cosewic/sr-RoqualCommunFinWhale-v00-2019-Eng.pdf

Examination of fin whale reveals it was killed by collision with ship. Cascadia Reserach Collective. https://cascadiaresearch.org/project_article/examination-fin-whale-reveals-it-was-killed-collision-ship/

Fin Whale Mistaken For A Minke Whale Causes Excitement In Central Puget Sound. Sarah Montour Lewis. Our Wild Puget Sound. https://www.ourwildpugetsound.com/journal/fin-whale-mistaken-for-a-minke-causes-excitement-in-central-puget-sound

‘Rare sighting alert’: Fin whale spotted near North Seattle beaches. KIRO 7 News. January, 22, 2022. https://www.kiro7.com/news/local/rare-sighting-alert-fin-whale-spotted-near-north-seattle-beaches/F2OORUTV5FANPGEYJ424WE2W5I/

New 2019 Sighting of Rare Fin Whale in Salish Sea! Puget Sound Express. September 12, 2019. https://www.pugetsoundexpress.com/new-2019-sighting-of-rare-fin-whale-in-salish-sea/

Acknowledgments

The author thanks Erin Falcone for data on fin whale photo-ID sightings, Jeff Rice and Joe Gaydos for comments on an earlier draft, the University of Washington Puget Sound Institute for funding, and the Puget Sound Ecosystem Monitoring Program's Marine Mammals Work Group for facilitating the production of this chapter.

Licensing & attribution

Data and products from the PSEMP Marine Mammal Work Group are governed by a Creative Commons BY-NC-SA license. Attribution should be to: “PSEMP Marine Mammal Work Group” with a link back to https://psemp.net/mmwg.