SALMON AND TROUT IX ALASKA. 97 



bers from the propagation stations of the upper river. A careful 

 study of the king sahnon's movements on the Cokimbia is much to 

 be desired. The greater length of the river, more numerous branches, 

 and higher latitude and altitudes make that basin an extraordinary 

 field for research, and its very great economic value demands the 

 results. 



SPAWNING STREAMS CHOSEN BY THE COHO, DOG, AND HUMPBACK 



SALMON. 



The coho apparently demands a yet lower temperature for spawn- 

 ing than the sockeye. Where it enters lake outlets early, it presses 

 into the higher waters in much the same manner. It differs in that 

 it often selects streams not connected with lakes, but in all cases its 

 later arrival from the sea finds the temperature low. While the most 

 active of any species, long journeys do not find favor with it. Wal- 

 lowa and Baker lakes seem to be at about the limit to which it travels. 



In the Naha in 1903 the cohoswere spawning October 27 in a tem- 

 perature of 46°. This is probably about the temperature at which 

 they begin. During October and later the small streams fall rapidly 

 in temperature, so that scarcely any running water after that date 

 would be too warm for spawning purposes. Since in favorable places 

 the coho continues spa^\^ling throughout most of the winter, any 

 temperature above freezing does not seem to be prohibitive. At 

 Hetta it is reported that the cohos sometimes spawn in small num- 

 bers throughout the winter, even as late as March. This lake is said 

 to have areas of open water, perhaps due to warm springs, about 

 which sockeyes spawn until February. Alexander (ms. notes) 

 states that in the winter of 1902-3, while the lakes and stream were 

 frozen over, one of the lakes of South Olga stream, Kadiak Island, 

 was visited by a party of white men and Indians who found a 

 large number of sockeyes and cohos frozen in the ice. These were 

 thought to be late-run fish entering after the canneries had closed. 

 Many carcasses of salmon that had been frozen in the ice were seen 

 by Rutter at Karluk Lake in the spring of 1903. In that stream 

 the occurrence at times of late runs arriving after the usual closing 

 time of the cannery early in September is well knowai. They more 

 frequently occur in seasons of a small early run, and at such times 

 the cannery is held open for them. The carcasses of winter spawners 

 were still to be seen on Trail Creek the last of May, 1904. 



The dog and humpback salmons apparently exercise less discrimi- 

 nation than other species. The hump])ack was noted as working 

 upstream in the Naha at 61° August 25, 1903, and in the Anan at 58° 

 August 30, 1904; yet it had completed spawning in the outlet of 

 Yes Lake September 11, 1905, in temperatures around 56°. Karta 

 River, September 12, 1903, was full of both dog and humpback sal- 



