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were captured the first time. The fidelity to these areas 

 persisted even though streamflow discharges dropped by about 20% 

 between the times of the two inventories. 



The possibility of interspecific competition between brook 

 trout and Arctic grayling was investigated. Distinct differences 

 in habitat utilization by age I and older fish were seen. Brook 

 trout were most abundant in the higher gradient, upper sample 

 sections of the Study Area, but were present throughout the Study 

 Area. In sample sections where both species occurred, there was 

 a tendency for brook trout to occupy faster water, often in 

 association with undercut banks or overhanging terrestrial 

 vegetation. The brook trout were not restricted to this type of 

 water, however, and were found in lesser numbers in typical 

 grayling habitat as well, which was slow runs or pools with 

 depths typically at least 2-3 ft. Often, the pools could be 

 characterized as backwater areas with foam on the water surface. 

 Differences in habitat utilization by young-of-the-year fish were 

 also seen. In areas where high densities of Arctic grayling fry 

 were found, brook trout fry tended to occupy a wider range of 

 habitats than the grayling — using areas ranging from slow, 

 shallow runs to fast riffles. Occasionally the two species were 

 found in the same areas. The possibility of spatial segregation 

 by the two species of fry was investigated by linear regression 

 analysis. Although the negative correlation was not significant, 

 there was a tendency for one of the species to be in low numbers 

 if the other species was in high numbers. 



