94 SALMON AND TROUT IN ALASKA. 



SELECTION OF SPAWNING GROUND. 

 CONDITIONS REQUIRED BY THE SOCKETE. 



Interesting preferences are shown by the mature salmon on coming 

 out of the lakes to spawn. The first run of sockeyes at Fortmann 

 Hatchery (usually of somewhat smaller fish) enters McCune Creek. 

 This creek is a mile or so in length and drains a slope to the southeast- 

 ward of the lake, the mouth, as will be seen from the map, being 

 but a few yards from the entrance of the main stream. The lower 

 course is over fine gravel and has but a moderate fall. 



On July 28, 1903, Heckman Lake at the surface was 64°, Naha 

 River at the hatchery 60°, McCune Creek 53°. There were no 

 spawners in sight. August 27 the river was 61° and the creek 52^°, 

 and fish had been spawning a week. At this time some fish were 

 showing a preference for the creek, which was fenced. Considerable 

 numbers of ripe fish were in the river. October 15 the river was about 

 46°; November 17, 36*°. 



Selective discrimination is also shown in Jordan Lake. Emma 

 Creek, tributary to that lake, has a small lake near its source in 

 which its water is somewhat warmed. Gibson Creek, a larger stream, 

 evidently has no expansion in its course, for its waters are always cold. 

 Sockeyes are never knowTi to spawn in Gibson Creek, which carries a 

 temperature of 48° or less, while Emma Creek, between 50° and 60°, 

 is to a small extent made use of. 



August 18, at Nowiskay, North Arm of Moira Sound, the main 

 stream above was 51°, the lake over the spawning beds 62^°. A 

 few fish were in sight, but none spawning. This stream is 44° and 

 the lake 46° to 45° during the spawning season. No sockeyes enter 

 the stream, though dog and humpback salmon do. The sockeyes 

 spawn about the lake shores. 



At Karta Lake, September 11, Willow Creek was 50^°; Alder 

 Creek, 47 i°. Sockeyes were spawning in both in about equal numbers, 

 or slightly preferring Willow Creek, perhaps for its greater size. The 

 main river below the lake was 53^° and full of dog and humpback 

 salmon. 



At Yes Bay, September 19, 1903, the river above was full of spawn- 

 ing sockeyes, temperature 50°; sockeyes were also entering the 

 flooded creeks at 70°. September 14, 1904, the surface of the lake 

 was 52°, the water over the beds, 49.5°; in the pool above, 48.5°; a 

 feeder of tliis pool, 46°. May 2, 1905, the temperature of the main 

 stream had reached 49°. Early in September of that year salmon 

 were spawning in water of 51°. 



At Quadra, August 1, 1903, the lake surface was 63° to 65°. Osten 

 Creek, at the head of the lake, in which the fish spawn, 51° at 3 p. m. ; 

 the sockeyes had just begun to appear at this stream. A fine creek 



