Fin whales are the second largest species of whale, therefore is the second largest living animal on earth (the blue whale is the largest). They are part of the family of rorqual whales (baleen whales with throat grooves), have a long sleek, streamlined body that can be up to 85 feet long and weigh between 80,000 and 160,000 pounds (40 – 80 tons). They travel singly, in pairs, or in pods of 6-7 – most often seen in pods 25 miles or more from shore.

Fin whales in U.S. waters have been divided into four stocks – Hawaii (2002 estimate of 174 whales), California/Oregon/Washington (reliable estimate not available), Alaska (1984 aerial survey of Akutan whaling grounds produced no sightings, 1994 Aleutians ship survey failed to find appreciable numbers), and Western North Atlantic (population estimate 1,678).

Populations in all oceans were greatly reduced by historical commercial whaling. Hunted in larger numbers than any other whale during the 20th century with 725,000 killed in the southern hemisphere, assessment estimates that the global population has declined by more than 70% over the last three generations (1929 – 2007). There is serious concern that due to lack of food supply, this decrease will not only continue, but is probably increasing. The trend in the North Pacific subpopulation is uncertain; based on ship surveys, the 2003 population estimate was approximately 2,541 whales, but there is not enough data available to assess trends.

Current threats to fin whales

• Ship strike – of all species of large whales, fin whales are most often reported as hit by vessels.
• Entanglement in fishing gear
• Reduced prey abundance due to overfishing
• Habitat degradation
• Disturbance from low-frequency noise
• Whaling – Despite the 1986 IWC ban on commercial whaling, some countries refuse to end their whaling operations.
  • Japan
    Almost immediately after the 1986 whaling ban came into effect, Japan launched its ‘scientific’ whaling program, widely recognized as a cover for its ongoing commercial whaling operation.Meat from these whales — supposedly killed for science — is then sold in food markets or given away free or at low costs to schools and hospitals in marketing drives to encourage the consumption of whale meat.The Japanese whaling fleet departs twice a year. In the North Pacific, Japanese whalers can kill up to 200 minke whales, 50 Bryde’s, 100 sei whales and 10 sperm whales under the guise of scientific research. Vessels had been killing up to 935 minke whales and 50 fin whales each year in the Southern Ocean Sanctuary before the International Court of Justice ruled that this was illegal.

    In the 2011/2012 season, Japan killed 445 whales, 2 of which were fin whales.

  • Norway
    Norway only respected the IWC’s whaling ban until 1993. Using a loophole in the International Convention for the Regulation of Whaling, Norway objected to the whaling moratorium, and resumed hunting for minke whales.Norway sets its own quota for the number of whales its whalers are permitted to kill for commercial reasons. There is no data available for possible fin whale kills.
• Fishing – Fin whales sometimes die as by-catch of the fishing industry.
• Drilling for oil and gas
  • There is a growing concern over the potential effects of human-produced underwater noise on large whales; the recovery rate of fin whale populations from past exploitation could be impeded by low-frequency sounds generated by human activies such as seismic surveys and drilling. During exploration, noise is also produced by supply vessels and low-flying aircraft, construction work, and dredging. The severity of this threat is unknown and the uncertainty of this threat is high (learn more about current Shell arctic drilling). Whales rely on sound to communicate – human-produced underwater noise hampers, among other things, the whales’ ability to attract a mate. Scientists estimate that the area over which whales can hear one another has dropped by 90% because of overall noise pollution.
  • It is often lamented that the most easily anticipated disaster is an oil spill. Frightening amounts of oil spilled in accidents are never recovered at all, but ‘dispersed’ with chemicals – leaving toxic oil in the ocean environment along with toxic clean-up chemicals. Note that the 1989 Exxon-Valdez oil spill (11 million gallons) in Alaska’s Prince William Sound destroyed fisheries that had been successful for generations. Wildlife in that area suffers consequences to this day, 26 years later. It is still possible to dig holes in beaches along the Prince William Sound and find pockets of oil left over from 1989. It’s also noteworthy that neither Exxon or BP – 2010 Deepwater Horizon spill (205 million gallons) – have actually paid all the costs levied against them for clean-up attempts. (Learn more about continuing effects.)
  • See underwater detonations listed under Naval training.
• Naval training
  • Sonar – The effect of active sonar on fin whales has not been studied extensively and remains uncertain; however, active sonar associated with naval training activities might adversely affect fin whales in several different ways. First, low-frequency sonar transmissions that overlap with fin whale vocalizations might mask communication between whales which would affect the social ecology and social interactions of fin whale groups. Second, overlap between fin whale hearing and low- to mid-frequency active sonar transmissions might result in noise-induced losses of hearing sensitivity or behavioral disturbance as fin whales avoid or evade sonar transmissions.
  • Underwater detonations (Naval and oil exploration) – Underwater detonations associated with military training activities range from large high explosives such as those associated sinking exercises or ship shock trials, to missile exercises, gunnery exercises, mine warfare, disposal of unexploded ordnance, and grenades. Detonations produce shock waves and sound fields of varying size. Animals that occur close to a large detonation might be killed or seriously injured; animals that are further away might suffer lesser injury (i.e., tympanic membrane rupture or extensive lung injury). The relatively large spatial scale, frequency, duration, and diverse nature of these training activities in areas in which fin whales also occur suggests that these activities have the potential to adversely affect fin whales. (Learn more about whale deaths attributed to underwater detonations.)

Quick facts

• Fin whales are the second largest animals on earth.
• Length: Up to 75-85 feet.
• Weight: Up to 80,000-160,000 pounds (40-80 tons).
• Fin whales are largest in the Southern Hemisphere.
• Appearance: They have a sleek, streamlined body with a V-shaped head. The back and sides of the body are black or dark brownish-gray and the ventral surface is white. Their unique, asymmetrical head color is dark on the left side of the lower jaw and white on the right side. Fin whales have 50-100 throat grooves which expand when feeding. With fin whales, the dorsal fin is backswept in a graceful arc.
• Orcas are their only hon-human predator.
• Lifespan: 80 – 90 years.
• Males become sexually mature at about 6-10 years of age and females at 7-12, but physical maturity is attained around 25 years of age.
• Newborn calves are typically 18 feet long and weight about 4,000 – 6,000 pounds.
• Diet: Krill, small schooling fish such as herring, capelin, and sand lance, and squid.