Table 1.- -Percentage of bottom materials passing through 0.833-mm. sieve and 

 coefficient of permeability of 19 bottom samples measured on three dates 



[Permeability readings corrected for standard viscosity of 1.0 centipoise at 68° F.] 



August 29 August 30 Mean 



Percentage 

 passing through August 26 

 0.833-mm. sieve 



percentage by volume of a bottom sample 

 passing through an 0.833-mm, sieve. Per- 

 centage of materials passing through an 0.833- 

 mm. sieve are given in table 1 along with the 

 observed values of the permeability coefficient. 

 Mean permeability is plotted against per- 

 centage of materials passing through an 0.833- 

 mm. sieve in figure 6. 



It is apparent that permeability is high 

 where bottom materials contain less than 5 

 percent by volume of sands and silts passing 

 through an 0.833-mm, sieve. Low permeability 

 occurs where bottom materials contain more 

 than 15 percent by volume of sands and silts 

 passing through an 0,833-mm, sieve. 



SIZE COMPOSITION AND 

 SPAWNING SUCCESS 



Bottom samples were obtained from sam- 

 pling areas in six streams. Most of the effort 



was expended in five streams near Hollis 

 (Old Tom, Maybeso, Indian, and Twelvemile 

 Creeks, and Harris River). Samples also were 

 collected from Anan Creek, which is located 

 about 75 miles northeast of Hollis and is one 

 of the most productive pink salmon streams 

 in Southeastern Alaska. ^ 



All six streams were sampled in summer 

 1959 shortly before spawning began. Table 2 

 gives the mean percent by volume of solids 

 retained by sieves and settling from suspen- 

 sion in 10 minutes. Pronounced differences 

 were found in volumes of fine sands and silts 

 in the various spawning beds (fig, 7). 



^ For estimates of spawningescapementssee"Stream 

 Catalog of Southeastern Alaska Regulatory District No. 

 2" (Special Scientific Report--Fisheries No. 453) and 

 "Stream Catalog of Southeastern Alaska, Regulatory 

 Districts Nos. 5, 6, 7, and 8" (in preparation at the 

 Fisheries Research Institute for publication as Special 

 Scientific Report— Fisheries). 



