Balaenoptera physalus
fin whale

The fin whale is global in distribution but is not common in tropical seas and polar seas with ice.

Fin whales are a pelagic and nearshore species, sometimes occuring in water as shallow as 30 meters..

Fin whales are brownish grey above and white below. The color pattern is asymmetrical: the lower jaw is white on the right side and dark on the left. Fin whales are second only to blue whales in length but are more slightly built. The dorsal fin is strongly curved and is about 60 cm high. Fin whales have an average of 85 throat grooves that extend to the navel. Each side of the upper jaw bears 350-400 baleen plates. At physical maturity, males and females average 19 and 20 meters in length, respectively. Adults have not been weighed, but calculations suggest that a 25 m animal could weigh as much as 70,000 kg.

Fin whales are variably gregarious. The usual pod size is 6 or 7 individuals, but groups as large as 300 have been observed migrating together. Fin whales are migratory. In general, the spring and early summer are spent in cold, high latitude feeding waters. In the fall populations tend to return to low latitudes for the winter breeding season, though may remain in residence in their high latitude ranges if food resources remain plentiful. Because of the alternation of seasons in the two hemispheres, northern and southern populations never meet in equatorial waters. The fin whale is among the fastest cetaceans and can sustain speeds of 37 km/hr. They can reach depths of 230 m with ease and remain under for up to 15 minutes. Fin whales are known to leap completely out of the water. The spout is vertical and narrow and can reach heights of 6 m. Fin whales produce a wide variety of low frequency sounds and may also produce high frequency pulses.

Fin whales eat a variety of planktonic animals, including crustacea, squid, and fish. In the Antarctic Sea the crustacean Schizopoda constitutes a large part of the diet.

Fin whales were heavily hunted for their blubber, oil and baleen.

The fin whale is listed as endangered by the USDI and is on Appendix 1 of CITES; it is only listed as vulnerable by the IUCN. Fin whales were heavily hunted over the last century. Harvests from 1946-1965 exceeded 10,000 animals per year. International Whaling Commission quotas were lowered in the mid '70s and were reduced to zero by 1985, with the exception of a small (e.g., 10 in 1987) aboriginal catch and catches for "research" purposes. However, these restrictions may have come too late. Southern ocean populations are currently estimated to be no more than 5,000 individuals and probably only 2-3000. As with the blue whale, it is not certain that the fin whale has been saved from extinction by wanton overhunting.