48 SALMON AND TROUT IN ALASKA. 



HUMPBACK SALMON. 



The fry of the humpback salmon leave the fresh water with the 

 breaking up of ice. In 1903 they were first taken April 12 at station 1 

 on the Naha, but the number secured, 240, indicates that this was not 

 the beginning of the run, though all the lakes were stiU covered with 

 ice. The number migrating increased from this date to the end of 

 the month, and they were found leaving the lagoon throughout 

 May. During this time there was uq increase in average size, the 

 fry apparently leaving as rapidly as they attained sufficient strength. 

 They traveled almost wholly by night, the heaviest movement 

 apparently being on the first of falling water after a rise. At these 

 times the average size was slightly less than at others. On April 19 

 a trap set near station 3 took over 1 ,500 iry. There is but a very small 

 spawn'ng ground below Jordan Lake above the point where this net 

 was set, and it is thought that the larger part of the run indicated 

 by this catch had passed through Jordan Lake under the ice. The 

 average size was a trifle greater than that of the fry taken at the same 

 time at station 1 , wholly because of fewer undersized fish. 



Very few humpback fry were seen at Karluk, a few were taken at 

 the mouth of the river May 11, and again July 3, but at no time did 

 they appear abundant. One example occurred in an experiment 

 testing for endurance of salt water and was found to survive the test. 



While the young humpbacks are in fresh water, feeding is only 

 incidental. A few have been found to contain remains of insects, 

 larva?, and Crustacea. As with the dog salmon and coho, the descent 

 from the small creeks in which many are hatched makes it necessary 

 that they be able to stantl a quick change to salt water. In carrying 

 a number from the trap in fresh water to the lower Naha Bay it could 

 not be observed that immediate immersion in salt water caused them 

 the least inconvenience. 



TROUT (STEELHEAD?) AND CHARR. 



The first trout fry appear in Steelhead Creek about July 1. On 

 that date in 1903, 255 were taken in the trap, and on the following 

 day 295. About the same number were present again in 1904, 283 

 being taken on July 9. While no further trials of the trap were made 

 in 1903 the fry were noted to continue in the creek in large numbers 

 until swept out b}^ the faU rains about the middle of September. 

 During this period their abundance was almost incredible when 

 viewed with regard to the number of adults seen in the spawning 

 season. 



In the lower Karta River July 26, 1903, trout fry were very numer- 

 ous. At this time the temperature was 64° and the stream very low. 

 Along the sandy bars in places the receding of the water had left 



