Scientific name: Balaenoptera physalus
Physical description and related species
The fin whale is a marine mammal of the baleen whale suborder. It is second in length only to the blue whale, growing to nearly 26 metres.
Fin whales are dark grey to brownish black dorsally (top side), grading to pale or white ventrally (belly side). The undersides of the flippers and flukes are also white. The head is asymmetrical in colour; it is mostly dark but the right lower jaw is white. Baleen plates are black on the left jaw and white on the right jaw.
Like all baleen whales, females are slightly larger than males.
The southern fin whale (Balaenoptera physalus quoyi) is a subspecies of fin whale that lives in the Southern Ocean.
Distribution and abundance
The highest population density occurs in temperate and cool waters, in open ocean and is absent from waters close to the ice.
The biology and life history of the species is poorly known. The fin whale was second to the blue whale in commercial importance because of its size and wide ranging distribution. There are no estimates of current fin whale abundance for the southern hemisphere or for Australian waters.
Fin whales are widely distributed in both hemispheres between latitudes 20–75°. The species is more common in temperate waters, and the Arctic and Antarctic Oceans. Areas of upwelling and interfaces between mixed and stratified waters may be an important feature of fin whale feeding habitat. In the Antarctic the species is seen feeding both at the ice edge and further to the north inareas of complex bathymetry.
In Australia, there are confirmed records of fin whales for all coastal waters except in New South Wales and the Northern Territory, but the available information suggests that the species is more commonly present in deeper water.
Threats
Like all other large whales, the fin whale was heavily hunted during the twentieth century. 700,000 were killed in the Southern Ocean from 1904, when intensive commercial whaling began, until protection in 1975.
Conservation status: endangered
Diet and feeding
In the Antarctic fin whales feed primarily on krill.
