I 



I 



5 10 15 20 



Percentage of bottom sample by volume 



passing through 0.883-mm. sieve 



Figure 6. — Relationship observed between coefficient 

 of permeability and the fraction of the total volume of 

 stream bottom materials passing through an 0.833-mm. 

 sieve. (Curve fitted by eye.) 



According to unpublished data on weir counts 

 and visual estimates, the number of adult 

 pink salmon spawning in Anan Creek on oc- 

 casion has exceeded 1 million, and in most 

 years exceeds 100,000. Five random samples 

 were obtained from a large spawning riffle 

 in Anan Creek about 3 miles upstream from 

 the estuary. Even with this small number of 

 samples, it was apparent that virtually no 

 silt and little fine sand were present and 

 that bottom materials were highly permeable. 



Estimated escapements of pink salmon have 

 been lower in Maybeso Creek than in any of 

 the other streams sampled. A few hundred pink 

 salmon spawn some years in the intertidal 

 zone of Maybeso Creek, where 20 percent of 

 the total volume of solids present in an inter- 

 tidal riffle were found to pass through an 

 0.833-mm. sieve, indicating extremely low 

 permeability. 



Escapement estimates indicated that in the 

 most years Twelvemile Creek was considered 



Anan 



upstream] 



Indian 



intertidal 



Old Tom 



intertidal 



Harris 



upstream 



intertidal 



Relative escapement 

 Very high 

 Medium to high 

 Medium to high 



Fair to medium 



Twelvemile 



upstream 



intertidol 



Low to fair 



Maybeso 



intertidal 



:lc 



10 



— 1 — 

 15 



— I — 

 20 



Percentage of solids passing through 0.833 -mm. sieve 



Figure 7.--Percentage of the total volume of bottom 

 materials in six Southeastern Alaska pink salmon 

 streams passing an 0.833-mm. sieve. Samples were 

 collected in summer 1959. The streams have been 

 ranked in accordance with approximate levels of pink 

 salmon escapements weighted by available spawning 

 area. 



to be a marginal spawning stream, although it 

 supported larger runs of pink salmon than 

 Maybeso Creek. Although Twelvemile Creek 

 comprises several miles of spawning ground, 

 pink salmon escapements rarely exceed a few 

 thousand adults. Size composition of bottom 

 samples shows that intertidal and upstream 

 spawning grounds in Twelvemile Creek con- 

 tain large volumes of fine sands and silts and 

 have low permeability. 



Estimates of pink salmon escapements into 

 Harris River, Indian Creek, and Old Tom Creek 

 have varied greatly, but sizable runs have 

 been recorded for each of these streams in 

 some years. Runs into Harris River and Old 

 Tom Creek commonly include tens of thousands 

 of adult pink salmon and may exceed 50,000 

 on occasion. Both streams have extensive 

 spawning grounds, with Harris River being 

 larger. Spawning grounds in Indian Creek are 

 limited by comparison, but escapements of 

 thousands of adult pink salmon commonly 



