KARLUK RIVER RED-SALMON INVESTIGATION 



67 



be observed about the weir, through which they had no difficulty in passing, and were 

 especially conspicuous in the brackish lagoon below the weir, where they seemed to 

 linger a brief while, accustoming themselves to the denser medium. In the lagoon 

 the red-salmon fingerlings have the habit of leaping freely into the air, thus giving 

 some clue to the distribution of schools within the lagoon and to the density of the 

 population. The general belief of all observers in 1925 was that the fingerling 

 migration compared well with previous years and may have been larger than was 

 observed in 1924; but the basis for this judgment obviously was inadequate, and 

 little dependence can be placed on it. If we were dealing with well-ascertained data, 

 which indicated a fingerling migration in 1925 equal or superior to that of 1924 (the 

 foundation of the run of 1926), we could ignore the dismal predictions based on the 

 very limited spawning reserve of 1922 and could look forward confidently to a suc- 

 cessful run in 1927. In that case we should be forced to conclude that the relatively 

 few spawners of 1922 had encountered extraordinarily favorable conditions and had 

 produced a colony of fingerlings far beyond the ordinary. The possibility of such 

 an occurrence emphasizes the high value of a fingerling estimate, even if this be only 

 roughly approximate; but the general impressions concerning the fingerlings of 

 1925 are not of sufficient validity to do more than inject a certain element of doubt 

 into the situation beyond that which was already present. 



3. There remains to consider the evidence obtainable from the size of the 4 3 

 grilse group present in the 1926 run. As we have shown elsewhere, these grilse 

 appear in limited numbers in the early part of each run, then dwindle in numbers or 

 wholly disappear during the middle of the season, and reappear in a run of consider- 

 able proportions late in August and during the first half of September. Our observa- 

 tions cover the years 1924, 1925, and 1926, and are derived in part from random 

 sampling throughout the season, but chiefly from special studies of their relative 

 abundance carried on late in the season. These studies were also based on the method 

 of random sampling, but on a much larger scale than was found adequate for other 

 purposes. We shall confine our attention here to the special examination of the 

 catch made during certain days in September of each of the three years, the fish 

 being taken at random from the fish bins at Larsen Bay or Uyak. 



In 1924, on September 8, 300 fish were taken at random from the bins at Larsen 

 Bay, 44 of which (14.7 per cent) were of the 4 3 group. On September 9, 300 more 

 were examined, of which 45 (15 per cent) were 4 3 's. A third sample, of 300, was 

 taken on September 11, which proved to contain 32 of the 4 3 group (11 per cent), 

 and a fourth sample, on September 12, of 200 fish, contained 25 (12.5 per cent). 

 Of the above 1,100 fish examined from September 8 to 12, there were 146 4 3 's, 

 amounting in all to 13.4 per cent; 90 per cent of these were males and 10 per cent 

 females. 



In 1925, similar series of determinations were made on September 8, 9, and 11. 

 Five hundred were examined on each of the first two dates and 300 on the last, and 

 the percentages of the 4 3 group ran, respectively, 11, 25, and 15. In view of the 

 wide disparity of the three dates, it would have been desirable to extend our series 

 in both directions from the dates selected; but limitations placed on the fishing 

 season that year made further experiments along this line impossible. We are left 

 in doubt, therefore, whether the 25 per cent observed on September 9 or the 11 and 



