Fin Whale 



Balamoplera physalus fLinnaeus, 1758) 



The widespread distribution of fin whales in r!-.e North Pacific, 

 fi'om the ice edge in the Arctic to lower latitudes around 20 N along 

 Asian and North American coasts, has confused many attempts to 

 define the species' seasonal movements. In summer, large concentra- 

 tions of fin whales have frequently been seen in high latitudes feeding, 

 primarily on dense concentrations of euphausuds. Such feeding ag- 

 gregations helped support shore whaling stations at Akutan (eastern 

 Aleutians), Kodiak Island (Gulf of Alaska) and along the coasts of 

 Washington, Oregon and California during the early 1900 s. Whalers at 

 these stations killed large numbers of whales (mostly fin, blue and 

 humpback J from small catcher boats operated within an approximately 

 loonm radius of the whaling stations. The seasonality of observations 

 and kills of whales at these stations (both primarily in summer) long 

 provided our best understanding of the distribution and migration 

 patterns of most great whales in the eastern North Pacific. From such 

 data, fin whales were noted to appear off Vancouver Island, British 

 Columbia, as early as March. Fin whales were killed, and were 

 apparently most abundant, off Admiralrv Island in the Gulf of Alaska 

 in August. Nearly all fin whales killed by Akutan and Port Hobron 

 whalers were killed from May through September with a peak in 

 August. Collectively, these data suggest an influx ot some fin whales 

 into northern temperate waters for the summer season. The absence of 

 whaling in winter months has left open the question of whether or not 

 some fin whales remained in northern temperate waters year-round. 



Farther south, fin whales were commonly taken off California in 

 May, June, July, and August, indicating that not all whales migrated 

 from subtropical to northern temperate/subarctic waters. Further- 

 more, miscellaneous sightings of fin whales during the past thirty years 



FlGURL 11. [in whales, the second largest ot the rorquals, are present in the 

 SCB in small numbers at all seasons but their numbers apparently peak, 

 mainly in waters west of the Channel Islands, in early summer. (Photo by P. 

 C Howorth.) 



indicate that significant numbers of this species occur oft Southern 

 California in all seasons, although numbers in that area peak, mainly in 

 waters west of the Channel Islands, in late May to early June. Mid- 

 summer whales may be either those transiting through the the area or 

 on their way north or south, those that reside in local waters year- 

 round, or both. In surveys conducted by the U.S. Navy and others from 

 1969 through 1978 fin whales were seen in low numbers but were 

 recorded in all months of the year. In surveys conducted in the SCB 

 1975-1978 by the University of California Santa Cruz for the Bureau of 

 Land Management fin whales were documented off Baja California 

 and in the SCB at all seasons, but the frequency of sightings in the SCB 

 did increase from June through September. 



Within the SCB, fin whales have been reported near the Santa 

 Rosa-Cortez Ridge, the Tanner-Cortes Ridge and near San Nicolas 

 and San Clemente islands. In winter they appear to reside principally 

 offshore, as they are most often seen outside the Channel Islands. In 

 summer we have seen them ourselves and are aware of sightings by 

 others off Painted Caves (N.W. Santa Cruz Island), in the Santa 

 Barbara Channel east of Yellow Bluffs, off San Nicolas Island, at four 

 locations along the southwest side of Santa Cruz Island, and at two 

 locations off the southwest side of Santa Rosa Island. 



Females are bred in winter and give birth one year later. Calves are 

 nursed for about seven to eleven months and are generally weaned 

 (often before the end ot the summer following birth ) while on 

 northern feeding grounds or while females are moving south in 

 autumn towards wintering grounds. Limited tagging data indicate that 

 some fin whales move from wintering (November - January) areas ofif 

 Southern California to summering (May - July) areas off Oregon and 

 British Columbia and in the Gulf of Alaska. 



It is generally assumed that some whales from the "Asiatic" and 

 "American" stocks move northward in summer to the Aleutian Islands 

 and into the Bering Sea, where they may intermingle. It is not known if 

 whales move between wintering areas as a result of such intermingling. 



Although the IWC considers the North Pacific as one management 

 unit, there is evidence supporting the idea that at least two stocks of fin 

 whales exist in the North Pacific; a "western" or "Asiatic" stock that 

 ranges along the coast of Japan and Siberia, and an "eastern" or 

 "American" stock that ranges along the coasts of Washington, Oregon, 

 California and Baja California and in the Gulf of California. Alter- 

 natively, it has been suggested that fin whales m the Gulf of California 

 (perhaps resident), in the East China Sea, and off California (including 

 whales occurring off British Columbia) may belong to isolated stocks. 



Small numbers of fin whales were killed off the coast of Japan from 

 at least the mid-seventeenth century through the early 1900s when 

 modern whaling techniques were introduced there. Annual catches 

 then increased to a peak of 1040 in 1940 and continued at joo to 400 

 per year until World War II. Catches in Japanese waters began to 

 decline in the mid-i940s and continued to decline until 1975, when the 

 IWC prohibited the taking of fin whales there. 



