from Brooks River into Brooks Lake; 

 (5) migratory behavior of juveniles. 



and 



AGE AND LENGTH OF SEAWARD 

 MIGRANTS 



To assess relative abundance, samples of 

 juveniles were captured with fyke nets during 

 the downstream migration. No attempt was 

 made to estimate total migration. Three nets 

 were fished nightly at the lake outlet during 

 periods of heavy migration, one near each 

 shore and one in midriver (figs. 10 and 11). 

 Usually the nets were fished for only an hour 

 a night, but five 24-hour and five all-night 

 samples were also taken. After June 1 1 when 

 the migration tapered off, only one net (no. 1, 

 fig. 10) was fished, and the sampling schedule 

 was changed from every night to every third 

 night or less. 



BROOKS LAKE 



Figure 10. --Locations of fyke nets at Brooks Lake 

 outlet, 1957. 



Only portions of each nightly catch were 

 usually processed: from May 21 to 31 (except 

 for all-night samples) about 20 fish per net; 

 from June 1 to 11, 5 fish per net; and from 

 June 17 to October 1, 20 fish per net excepting 

 the June 1-11 period, on nights when the total 

 catch per net was less than 20 fish, the entire 

 catch was processed. 



Figure ll.--Fyke nets and method of collecting juvenile sockeye salmon at Brooks Lake outlet, 1957. 



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