were fished on Latin-square schedules as follows: four 

 1.5-h periods (2100 to 0300) each sampling day from 31 

 May to 2 August and sixteen 1.5-h periods each sam- 

 pling day from 16 to 23 August. Seven Latin-square 

 sampling schemes were completed, three of 4 days 

 length and four of 1 day. The estimated outmigration 

 for each of the Latin-square schemes was: (1) from 

 2100. 31 May to 2100, 5 June (sampled every other 

 day). 43,700 age I and older; (2) 2100, 8 June to 2100, 

 15 June (sampled every other day), 3,210 age I and 

 older; (3) from 2100, 26 July to 2100, 2 August (sam- 

 pled every other day), 160,703 age 0; (4) 2100, 16 Au- 

 gust to 2100, 17 August, 151,240 age 0; (5) 2100, 18 

 August to 2100, 19 August, 50,075 age 0; (6) 2100, 20 

 August to 2100, 21 August, 13,120 age 0; and (7) 2100, 

 22 August to 2100, 23 August, 28,940 age 0. The num- 

 bers of each age of sockeye salmon migrating from 

 Coville Lake to Grosvenor Lake from 21 May to 15 

 September 1962 (based on the sampling with fyke nets) 

 were about 2,237,000 age and 60,500 age 1 

 (Table 13). 



1963. — In 1963 the outmigration of sockeye salmon 

 from Coville Lake was sampled from 20 June to 17 

 September. Fyke nets were fished in Coville River 

 from a cable as in 1962, but the location was about 15 

 m downstream where the river is 30 m wide and the 

 depth more uniform. Nets were fished on Latin-square 

 schedules 5 to 12 August and 13 to 17 September with 

 four sites and four 6-h fishing periods each day. The 

 estimated outmigration for each of the Latin-square 

 schemes was: (1) from 2100, 5 August to 2100, 12 Au- 



Table 13. --Estimated numbers of age and age 

 I sockeye salmon migrating from Coville Lake 

 to Grosvenor Lake (by 10-day periods) , May 29 

 to September 15, 1962, based on results of 

 fishing with 4-ft fyke nets in Coville River. 



Table 14. - -Estimated numbers of age and age 

 I sockeye salmon migrating from Coville Lake 

 to Grosvenor Lake (by 10-day periods), June 20 

 to September 17, 1963, based on results of 

 fishing with 4-ft fyke nets in Coville River. 



Several thousand age fish were captured 

 in 1-m fyke nets fished intermittently along 

 shore. These fish are assumed to have origi- 

 nated from spawning in Coville River. 



gust (sampling every other day), 120,100 age and (2) 

 2100, 13 September to 2100. 17 September, 28,275 age 

 0. The estimates of the juvenile sockeye salmon migra- 

 ting by 10-day periods from 20 June to 17 September 

 are 918,000 age and 8,300 age I (Table 14). The rela- 

 tively few age fish that migrated before 12 July were 

 probably not interlake migrants, but were progeny of 

 females that spawned in Coville River. 



1964. — The migration of juvenile sockeye salmon 

 from Coville Lake was sampled with the same 

 techniques and at the same cable site in 1964 as in 1963. 

 Sampling was done intermittently from 1 1 July to 8 

 September. The index net was fished on 31 days and 

 two Latin-square schedules were completed — one 

 from 31 July to 4 August and the other from 20 to 25 

 August. The estimated outmigration for each of the 

 Latin-square schemes was: (1) from 1800, 31 July to 

 1800, 4 August, 122,569 age and (2) from 1800, 20 

 August to 1800, 25 August (22-23 August not fished). 

 715,719 age 0. The estimates of the juvenile sockeye 

 salmon that migrated in 10-day periods from 1 1 July to 

 7 September 1964 are about 3,036,000 age and 3,900 

 age I (Table 15). 



Migration from Grosvenor Lake to Hiuk Arm 



The numbers of presmolt sockeye salmon migrating 

 from Grosvenor Lake to lliuk Arm, the next basin 

 downstream, was estimated from the results of fyke 

 netting in Grosvenor River. The nets were fished in- 

 termittently on 29 days between 30 May and 17 Sep- 

 tember 1962 and on 4 days between 10 August and 10 

 September 1963. On the basis of the seasonal variation 

 in the rate of catch of age fish in Coville and Gros- 

 venor Rivers, I assumed that the summer interlake 

 migration of this age group began about 15 July. Some 

 age I fish were usually found in the fyke net catches in 

 Grosvenor River and I assumed that these fish had 



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