FISHERY BULLETIN: VOL. 71, NO. 3 



same action has been observed to occur regu- 

 larly at Brooks and Chilko Lakes it is obviously 

 a regular part of the spawning behavior of 

 sockeye salmon that spawn in rivers below 

 lakes. It has not been observed regularly at 

 Karluk Lake but it must occur, since the weir 

 was made to pass fish downstream as well as 

 upstream sometime in the late 1950's. 



Thompson (1950, 1951) proved conclusively 

 that the bimodal structure of the Karluk sockeye 

 runs after 1921 was an artifact caused by the 

 fishery. He provided a series of figures from 

 the total weekly Karluk pack of the largest 

 canner in that area, that showed the transition 

 from a run with a single mode in the late 1890's 

 through the gradual destruction of the center 

 of the run, finally ending before 1921 with 

 the two modes representing the spring and 

 fall remnants. These had not been fished as 

 hard as the center and after 1921 they were 

 protected by federal regulations of the catch. 

 Rounsefell's Figure 2, based upon runs since 

 1921, is therefore of no significance concerning 

 the original runs. 



The reports of the International Pacific Salm- 

 on Fisheries Commission document the var- 

 iability in age at which fish of the same race 

 return fi'om the sea to spawn. Every peak cycle 

 of the major Fraser River races is normally pre- 

 ceded by a large run of 3-yr-old jacks that are 

 almost all males. The peak years are also usually 

 followed by a large run of 5-yr-old fish. This is 

 shown in the annual reports of the Commission 

 which describe the returns from the large Adams 

 River run or from the Chilko run. This varia- 

 bility in age of return is part of the normal 

 variability within any race of sockeye and 

 represents the adaptability of each race to 

 environmental variations. The age of return of 

 each race is never fixed, though in the success- 

 ful ones most fish usually return at a certain 

 age. The variation in age of return provides 

 protection against disasters such as occurred 

 at Hells Gate on the Fraser River in 1913, and 

 increases the probability of survival of each 

 race. Of course if a number of different races 

 are lumped together as Rounsefell has done 

 for both the Karluk and Fraser Rivers and the 

 variations in returning age classes are studied 

 without regard for the individual variation of 



each race, the results are meaningless. Correla- 

 tions between the main age group and inconse- 

 quential segments of any group of races such as 

 those mentioned by Rounsefell on page 655 of 

 his comments are of no significance and cer- 

 tainly do not prove that races do not exist in the 

 Karluk. Variations in time and space of the 

 numbers of 5- and 4-yr-old fish must be expect- 

 ed though the returning fish of each race to be 

 most successful conform in time within each 

 season with limits imposed upon it by the 

 composite of environmental factors that race 

 encounters during its entire life history. We 

 would expect the most successful portions of 

 the run to produce the most "strays" that re- 

 turn at odd times and places. 



It is difficult to appreciate Rounsefell's dis- 

 missal of the numbers of redds estimated for 

 the terminal streams, lateral streams, and lake 

 beaches in the Karluk watershed by the biolo- 

 gists who have been working on the Karluk (see 

 Rounsefell page 658 and compare with Burgner 

 et al., 1969). Rounsefell multiplied the number 

 of potential redd sites noted by Burgner et al., 

 in terminal streams by 4, in lateral streams by 

 about 4.2 and on the lake beaches by 10 with 

 no apparent justification other than his state- 

 ment that the estimates made by Burgner et al. 

 cannot be taken seriously. Using his most 

 conservative factor of 4, he should also have 

 increased the number of potential redd sites in 

 the Karluk which would then exceed 500,000. 

 The Karluk River could be expected to accom- 

 modate about 1,000,000 spawners. This would 

 in fact agree with 3 times the 400,000 estimated 

 to have spawned there in 1926, i.e., when that 

 figure is multiplied by the difference observed 

 by Bevan and Walker (1955) between stream 

 estimates of spawners and weir counts which 

 they established on Moraine Creek (see our 

 paper page 631). This also agrees with the 

 factor of about 3.0 established for Forfar Creek, 

 one of the small streams in the Stuart Lake 

 system of the Fraser River when the senior 

 author was chief biologist for the International 

 Pacific Salmon Fisheries Commission. Much as 

 we have always admired the pioneering biolog- 

 ical work of Rutter we cannot conceive that 

 his stream counts would be more accurate than 

 those of our modern salmon biologists. How- 



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