249 



DRAFT 



'White (1938) found an inverse relationship between stream flow and 

 percent of brook trout in the diet of kingfishers ... evidently the 

 kingfisher experienced increased feeding efficiency in slower moving 

 waters caused by stream diversions. ' 



Did White (1938) cite the cause of stream flow changes as water diversions, or did the 

 study measure predation rates under natural fluctuations of stream flow? 



'Studies (Mathews, 1983) have shown that the common murre... ' 



'Thus, the estimated 40,(XX) birds that occur off the Oregon coast each 

 spring could account for the loss of several million smoltsfor each month 

 that their presence coincides with the arrival ofsalmonid smolts. " 



The referenced study is not included in bibliography, so we were unable to verify the 

 accuracy of the cited information. In addition, we question whether the estitnated 

 consumption of salmonids by common murres was reported by Mathews, or if this 

 calculation was completed by the OFIC report authors. A listing of the assumptions 

 inherent to this calculation should be provided so that the validity of the estimate can be 

 evaluated. 



"McNeil et al. (1991) demonstrated that survival of hatchery-reared coho 

 salmon could be markedly improved by transporting them in net- 

 pens. ..avoiding bird and fish predation in nearshore waters. It is likely 

 that wild salmon smolts would be susceptible to the same type of 

 predation. ' 



While we agree that wild smolts would be susceptible to the same typ e of predation 

 (birds and fish), the amount of predation on hatchery fish is likely to be markedly 

 greater due to releases of large numbers of smolts within a short time period. These 

 hatchery release strategies may attract predators due to the concentration of prey 

 species (salmonids). The implication that wild smolt survival would be markedly 

 increased in the absence of this predation (as reportedly occurred at the private 

 hatchery) is unsubstantiated. 



Marine Mammal Predation (Pages 106-112) 



The report notes that protective legislation has resulted in increases in some marine 

 mammal populations in the Pacific Northwest, and suggests that: 



'...these recent increases in marine mammal numbers are causing 

 irKreased predation rates on salmonids. ' 



No reference or scientific substantiation is provided for this statement. While there are 

 reports documenting increases in some mammal populations over time, there are no 



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