Miller and Brodeur: Diets of and trophic relations among dominant marine nekton within the northern California Current ecosystem 



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Percent similarity of diets between nekton species 

 varied by year (Tables 2 and 3). During 2000 (Table 2), 

 highest similarity values were found between yearling 

 Chinook and yearling coho salmon (94%), yearling and 

 adult Chinook salmon (88%), and yearling coho salm- 

 on and adult chinook salmon (88%). Trophic groups B 

 (yearling and adult chinook salmon and yearling coho 

 salmon) and C (jack mackerel. Pacific saury, and Pacific 

 sardine) had the highest similarities in diet (mean 90% 

 and 58%, respectively). For trophic group B, larval- 



juvenile Osteichthyes and adult euphausiids together 

 accounted for over 80% of the total percent similarity 

 in diets among the three nekton, and larval-juvenile 

 Osteichthyes accounted for 60% of the overlap. Other 

 nekton that had significant (>60%) percent similarity 

 in diets (Table 2) were 1) jack mackerel and juvenile 

 steelhead trout and 2) juvenile steelhead trout and Pa- 

 cific herring; and the similarities were primarily due to 

 euphausiids, or to species that fed on euphausiids and 

 other mixed zooplankton, or in the case of adult coho 



