FISHERY BULLETIN OP THE FISH AND WILDLIFE SERVICE 257 



weir and the still water at the Larson Bay portage. The mortality included adult red salmon, hump- 

 backs, and trout, as well as young fish. The cause is unknown unless it was due to overcrowding of 

 humpbacks, with a possible fall of the water level in the river ... it is estimated that over four 

 million humpbacks passed through the weir this season. 



Quoting from Lucas' notes taken while visiting the red-salmon spawning grounds 

 at Karluk Lake, September 16 to 24: 



. . . Behind every rock and in every eddy piles of humpback eggs lay. Within twenty-two 

 steps the writer counted twelve piles that would average five gallons to a pile; and behind a small 

 island about six feet in diameter there were more than a fifty-gallon barrel full of humpback eggs. 

 These eggs were all dead; ... a small percentage of red eggs was among them. In fact, more or 

 less red eggs were noticed adrift in every stream where humpbacks had spawned . . . The dead, red 

 eggs . . . were more numerous than the live ones. All of these live eggs will probably be picked up 

 by the birds and trout before they hatch. . . . 



It was apparent that there was too large a pink-salmon escapement, and this was 

 borne out by the failure of the pink-salmon run of 1926, the total return from the 

 escapement of over 4,000,000 being less than 100,000 fish. The overcrowded con- 

 ditions on the spawning grounds in 1924 not only resulted in a very poor return of 

 pink salmon in 1926 but undoubtedly were largely responsible for the poor return 

 from the red-salmon escapement. 



The. escapement of 1925 (1,620,927), while good, also produced a relatively poor 

 return, and the total return was slightly less than the number of fish in the escapement. 

 Karluk Lake was not visited during the summer of 1925, and consequently no infor- 

 mation as to conditions on the spawning grounds during that year is available. The 

 moderately large escapement should not have caused an undue mortality due to over- 

 crowding under normal conditions, and there is no reason to believe environmental 

 conditions were abnormal during the spawning period. It is known that the winter 

 of 1925-26 was exceptionally mild. A mild winter should cause the eggs to hatch 

 earlier than usual, but just what effect this would have on the fry is impossible to 

 state. 



The excellent escapement of 1926 (2,533,402) suffered from unfavorable conditions 

 caused by an exceptionally warm, dry summer, and the return was 1,000,000 fish less 

 than the number of spawners in the escapement. The lack of rainfall coupled with a 

 large escapement of red salmon produced conditions somewhat similar to thoso 

 encountered in 1924. Quoting from notes made by Willis H. Rich in 1926: 



On July 18, in Spring Creek ... it was very noticeable that many of the females were not 

 completely spawned out; six of twelve examined had eggs apparently still in good condition. Most 

 of these were apparently not spawned at all, although ripe . . . Upper Thumb lliver ... we saw 

 many dead females, ripe but unspawned, and many others that were not completely spawned out. 

 Causes of death quite unknown, as most of them appeared to be in fine condition. 



Observers at Karluk Lake in 1926 considered that "about 25 percent of the 

 females that reached the lake died only partially spawned out." Not only did many 

 fish die before spawning, but large numbers of eggs deposited in the gravels died 

 because the spawning grounds dried up. Again quoting from Rich's notes: 



August 9 ... In Thumb River, where the spawning had been heaviest, many of the nests were 

 exposed by the lowering of the water. We dug in some of them and found mainly dead eggs, 

 although a very few live ones were found. 



In many of the other streams similar conditions were noted. Thus, the poor 

 return from the spawning of 1926 might have been due largely to the conditions on 



