576 



Fishery Bulletin 102(4) 



the continental shelf. Despite most of our effort being on 

 the continental shelf, the presence of several deep can- 

 yons in addition to the shelf edge, resulted in all species 

 being an average of less than 11 km from the 200 m 

 depth contour. The average surface water temperature 

 for species that were seen also varied and was likely 

 both a function of distance from shore and association 

 with upwelling areas (Table 9). Sea otters were seen in 

 the coldest waters (12.6°C) where they are predominant- 

 ly found. Among the more offshore species, humpback 

 whales, tended to be seen in colder waters (13.9°C) than 

 most other offshore species, probably because of their 

 association with offshore upwelling areas. 



Discussion 



Although humpback whales were the most abundant 

 large cetacean seen in our study, their numbers of a 

 few hundred still appear to be substantially lower than 

 numbers found prior to whaling. Commercial hunting 

 of humpback whales occurred in the 1900s from coastal 

 whaling stations in northern California, Washington, 



and British Columbia. In these areas, thousands of 

 humpback whales were killed over a relatively short 

 time period (less than 10 years) before catches dropped 

 precipitously with the depletion of the population. At 

 the south end of our study area, 1933 humpback whales 

 were taken from a station at Bay City (in Grays Harbor), 

 Washington, from 1911 to 1925 (Scheffer and Slipp, 

 1948). To the north, 5638 humpback whales were taken 

 from British Columbia stations from 1908 to 1967, of 

 which 60 f 'f (3393) were taken from 1908 to 1917 from the 

 two southernmost whaling stations on Vancouver Island 

 closest to our study area (Gregr et al., 2000; Nichol et 

 al., 2002). Additionally, 1871 humpback whales were 

 taken from two stations in northern California from 

 1919 to 1926 (Clapham et al., 1997). Although these 

 hunts encompassed areas larger than our study area, 

 the number killed in short periods dwarfs even the sum 

 of our abundance estimates for Washington and British 

 Columbia and the estimate of under 1000 whales esti- 

 mated in the 1990s for California. Oregon, and Wash- 

 ington (Calambokidis and Barlow, 2004). Moreover, 

 humpback whales have not returned to some of the 

 areas where they were once found prior to commercial 



