The fin whale is a vast, fast-swimming baleen whale found across the world's oceans, second in size only to the blue whale. Hunted in enormous numbers during the twentieth century, it is one of the better-documented success stories of international whaling regulation, though its populations remain far below historical levels. This page summarizes what primary scientific and government sources report about the species' biology, status, and recovery.
Biology and Identification
The fin whale is the second-largest living animal, reaching roughly 75 to 85 feet (about 23 to 26 meters) in length and weighing between 40 and 80 tons, with individuals in the Southern Hemisphere generally larger than those in the north [NOAA 2024]. A long, slender, streamlined body and a speed that earned it the nickname "greyhound of the sea" distinguish it; it is among the fastest of the great whales [NOAA 2024]. A diagnostic feature is its asymmetrical jaw coloration: the right lower jaw is white while the left is dark, with the reverse pattern on the tongue [NOAA 2024].
As a baleen whale, the fin whale is a filter feeder, consuming krill, small schooling fish such as herring, capelin, and sand lance, and squid; it can eat up to about 2 tons of food per day during the summer feeding season, then largely fasts in winter [NOAA 2024]. Fin whales are often seen in small social groups and may feed alongside other whale species [NOAA 2024]. They are long-lived, with lifespans estimated at 80 to 90 years and physical maturity reached around 25 years of age [NOAA 2024].
Habitat and Range
Fin whales occur in deep, offshore waters of all major oceans, primarily in temperate to polar latitudes [NOAA 2024]. The species is highly migratory in many regions, moving seasonally between higher-latitude feeding areas, such as Arctic and Antarctic waters, and lower-latitude wintering grounds [NOAA 2024]. The IUCN Red List describes the species as having a near-global distribution spanning the North Atlantic, North Pacific, and Southern Hemisphere, with recognized regional populations and subpopulations [IUCN 2018]. A genetically distinct Mediterranean subpopulation has been separately assessed by the IUCN [Panigada et al. 2021].
Conservation Status
The fin whale is listed as Vulnerable on the IUCN Red List, assessed in 2018 [IUCN 2018]. This represented an improvement from its previous global listing: the IUCN reported that the global population had roughly doubled since the 1970s, reaching an estimate of around 100,000 mature individuals with an increasing population trend [IUCN 2018; IUCN 2018b]. The IUCN attributed this recovery to the near-complete protection of the species, following international bans on commercial whaling in the North Pacific and Southern Hemisphere in place since 1976, and significant reductions in North Atlantic catches since 1990 [IUCN 2018b].
The Vulnerable classification reflects that, despite recovery, the species remains a small fraction of its pre-whaling abundance [IUCN 2018b]. In the United States, the fin whale is listed as Endangered throughout its range under the U.S. Endangered Species Act and is designated as Depleted under the Marine Mammal Protection Act [NOAA 2024]. Internationally, the species is listed on Appendix I of CITES, which prohibits commercial international trade in the species and its products [CITES 2023]. The genetically distinct Mediterranean subpopulation, with fewer than 10,000 mature individuals and an inferred continuing decline, is separately assessed as Vulnerable [Panigada et al. 2021].
Threats
NOAA Fisheries identifies the principal current threats to fin whales as vessel strikes, entanglement in fishing gear, ocean noise, climate change, and reduced prey availability linked to overfishing [NOAA 2024]. Vessel collisions are a documented cause of injury and mortality, particularly where shipping lanes overlap with feeding habitat [NOAA 2024]. Although commercial whaling no longer occurs across most of the species' range, commercial hunting persists in parts of the North Atlantic: Iceland issued five-year licenses in December 2024 authorizing the take of fin whales, and under a separate license, 99 fin whales were permitted to be hunted during Iceland's June–September 2024 season [Mongabay 2024]. Historical industrial whaling, which removed hundreds of thousands of fin whales over the twentieth century, remains the underlying reason the species sits well below its original abundance [IUCN 2018b].
What Is Being Done
The most consequential protection has been the International Whaling Commission's commercial whaling moratorium, adopted in 1982 and in force since 1986, together with earlier regional bans that allowed populations to begin recovering [IWC 2024; IUCN 2018b]. The IUCN SSC Cetacean Specialist Group conducts the scientific assessments that underpin the species' Red List status and monitors population trends [IUCN 2018]. In the United States, NOAA Fisheries manages the species under the Endangered Species Act and Marine Mammal Protection Act, including stock assessments and measures to reduce vessel strikes and entanglement [NOAA 2024]. CITES Appendix I listing restricts international trade [CITES 2023], and the U.S. Department of the Interior has acted under the Pelly Amendment to certify that Iceland's continued commercial whaling and trade in whale products diminishes the effectiveness of CITES [USFWS 2014].
How You Can Help
Members of the public can support fin whale recovery in factual, constructive ways. Reporting whale sightings, strandings, or entangled animals to national marine authorities such as NOAA Fisheries contributes to monitoring and rapid response [NOAA 2024]. Supporting established science-based organizations and the work of bodies such as the IUCN SSC Cetacean Specialist Group helps sustain the population assessments that guide policy [IUCN 2018]. Boaters can reduce risk by maintaining distance and slowing down in areas where whales are present, and informed advocacy for strong international whaling and trade protections supports the agreements credited with the species' recovery [NOAA 2024; IUCN 2018b].
References
[CITES 2023] Convention on International Trade in Endangered Species of Wild Fauna and Flora (2023). Appendices I, II and III. https://cites.org/eng/app/appendices.php
[IUCN 2018] Cooke, J.G. (2018). Balaenoptera physalus. The IUCN Red List of Threatened Species 2018: e.T2478A50349982. https://www.iucnredlist.org/species/2478/50349982
[IUCN 2018b] IUCN (2018). Fin Whale, Mountain Gorilla recovering thanks to conservation action – IUCN Red List. https://iucn.org/news/species/201811/fin-whale-mountain-gorilla-recovering-thanks-conservation-action-iucn-red-list
[IWC 2024] International Whaling Commission (2024). Commercial Whaling. https://iwc.int/management-and-conservation/whaling/commercial
[Mongabay 2024] Raman, S. (2024). Hundreds of whales to be harpooned as Iceland issues new hunting licenses. Mongabay. https://news.mongabay.com/2024/12/hundreds-of-whales-to-be-harpooned-as-iceland-issues-new-hunting-licenses/
[NOAA 2024] NOAA Fisheries (2024). Fin Whale (Balaenoptera physalus). National Oceanic and Atmospheric Administration. https://www.fisheries.noaa.gov/species/fin-whale
[Panigada et al. 2021] Panigada, S., Gauffier, P. & Notarbartolo di Sciara, G. (2021). Balaenoptera physalus (Mediterranean subpopulation). The IUCN Red List of Threatened Species 2021: e.T16208224A50387979. https://www.iucnredlist.org/species/16208224/50387979
[USFWS 2014] U.S. Fish and Wildlife Service (2014). Interior Certifies that Iceland's Commercial Whaling Undermines International Wildlife Conservation Treaty. https://www.fws.gov/press-release/2014-02/interior-certifies-icelands-commercial-whaling-undermines-international