Marine Mammals
Fin Whale
Balaenoptera physalus
ALSO KNOWN AS
Finback, Finner, Common Rorqual, Herring Whale
DISTRIBUTION
Global, except Arctic Ocean
ECOSYSTEM/HABITAT
Coastal and offshore waters
FEEDING HABITS
Filter feeder
TAXONOMY
Suborder Mysticeti (baleen whales); Family Balaenopteridae (rorqual whales)
SHARE
Fin whales are the second largest animals on Earth, only the blue whale is larger. Despite their massive size, fin whales have a slender and streamlined body that helps them to reach speeds up to 40 km/hr, making them one of the fastest swimmers of all the whales and earning their nickname of the “greyhounds of the sea”. Like all baleen whales, their diet consists of some of the tiniest animals in the sea, including krill, copepods, and small schooling fish. They expand the 60 grooves along their throats to help them engulf massive amounts of water. Unable to swallow saltwater, they filter out food using their baleen plates like a strainer. Interestingly, baleen is made of keratin, like our hair and fingernails.
Fin whales are the second largest animals on Earth, only the blue whale is larger. Despite their massive size, fin whales have a slender and streamlined body that helps them to reach speeds up to 40 km/hr, making them one of the fastest swimmers of all the whales and earning their nickname of the “greyhounds of the sea”. Like all baleen whales, their diet consists of some of the tiniest animals in the sea, including krill, copepods, and small schooling fish. They expand the 60 grooves along their throats to help them engulf massive amounts of water. Unable to swallow saltwater, they filter out food using their baleen plates like a strainer. Interestingly, baleen is made of keratin, like our hair and fingernails.
Fin whale bodies have evolved to be long, slender, and streamlined to help enable their great swimming speeds, which can exceed 40km/h. Their snout or rostrum is shaped like a wedge and they are easily identified by their small, hooked dorsal fin. Interestingly, the coloration of the fin whale’s jaw and baleen plates are asymmetrical; the lower right jaw is white and the lower left is black! Growing up to 27 metres in length and weighing up to 74 tonnes, females are usually between 5-10% larger than males.
Fin whales can dive up to 470 metres and hold their breath for up to 17 minutes when feeding, but considerably more shallow and shorter dives when resting and travelling. All three of the fin whale sub-species are highly migratory and live throughout all of the world’s oceans, except the Arctic Ocean. They are very social and can normally be found in groups of 6-10 individuals, although during feeding frenzies, groups of 100 or more have been documented.
Fast migratory animals, fin whales will travel great distances to follow their food all around the world. In the summer, the whales are found in high latitudes feeding on krill, copepods, herring, capelin, sand lance, and squid. In winter, they travel south to tropical and subtropical waters where they breed, although not much is yet known about these breeding grounds. Following an 11-12 month gestation period, females normally birth one calf every 2-3 years, although mothers can produce up to six calves at once. Calves can measure up to 6 metres in length, and will reach sexual maturity at approximately 12 years old. Full physical maturity is reached at 25-30 years old and fin whales can live to be 140 years old.
Despite being relatively safe from hunting in the 19th century thanks to their speed, fin whales became the target of the commercial whaling industry as technologies advanced in the 20th century. In the Atlantic, over 13,000 whales were harvested in the first half of the century; in the Pacific, thousands of whales were caught in the 1970s alone. While commercial whaling ceased in the 1970’s and 1980’s, some subsistence whaling continues today in Iceland and Greenland.
As a direct result of whaling and ongoing threats, the global population of fin whales is estimated to be less than 100,000 individuals and continues to decline. However, without reliable and recent estimates of all the populations it is difficult to say how the populations have changed over time and compare to pre-whaling population sizes. The recovery of fin whale has been hindered by the ongoing decline of their prey.
Although the Pacific and Atlantic populations of fin whales are considered distinct, both their conservation statuses were changed in 2005-2006 to better reflect the increasing risk of becoming endangered. Fin whales face many threats as a direct result of harmful human activity, with the greatest risk of mortality or injury due to shipping collisions, as well as entanglement in fishing gear, chemical and noise pollution.
Below are the conservation statuses of each Canadian population:
- Atlantic population. COSEWIC listing: Special Concern – 2005, SARA listing: Schedule 1, Special Concern – 2006
- Pacific population. COSEWIC listing: Threatened – 2005, SARA listing: Schedule 1, Threatened – 2006
