720 



Fishery Bulletin 97(3), 1999 





 Late spring 1994 

 B Late summer 1994 









50 

 45 

 40 

 35 

 30 

 25 

 20 

 15 

 10 

 5 

 



B 



 Late spring 1995 

 BLate summer 1995 



L 



I 



i 







li 11 tl -li 



I 8 -31 



a 

 I 



fr 

 X 



W 



1 2 



5 > 



13 



Figure 2 



(A) 1994 late spring and late summer index of importance (/O/i values for predominant prey 

 items consumed by chinook salmon, Oncorhynchus tshawytscha. in the coastal waters off 

 Humboldt Bay, Trinidad Bay, and Crescent City, California. (B) 1995 late spring and late sum- 

 mer index of importance I/O/) values for predominant prey items consumed by chinook salmon, 

 Oncorhynchus tshawytschn. in the coastal waters off Humboldt Bay, Ti-inidad Bay. and Cres- 

 cent City. California. 



(.I0I=n7c}. The index of importance indicates that 

 interannual and seasonal variation in the feeding 

 habits of chinook salmon does in fact occur, most 

 likely, in response to variation in the relative abun- 

 dance of prey along the coast. 



Healey (1991) summarized regional trends for 

 coastwide data on chinook feeding habits and recog- 



nized that the importance of Pacific herring and Pa- 

 cific sandlance increased from south to north whereas 

 the importance of rockfishes and northern anchovy 

 decreased. Our data agree with this summary. The 

 diet of chinook salmon off northern California con- 

 tained characteristic prey items important to chinook 

 found both to the north and south. Although our study 



