To test the survival of spawn and 

 conditions affecting it during the incuba- 

 tion Season, eggs are planted in the gravel 

 as described by Gangraark and Broad (1955). 

 The planted eggs are then grouped around 

 standpipes into areas resembling salmon 

 redds. The eggs are removed in part during 

 the season and percentages of survival 

 determined from original counts. 



Table 5 gives the environment and sur- 

 vival data recorded during the 1956-57 

 incubation season. In agreement with Wolf, 

 there is evidence that early critical flow 

 levels may not take their toll until the 

 young Salmon reach hatching or post-hatching 

 stage. In face of some irregularities re- 

 vealed concerning critical limitations of 

 flow presented in table 5, larger numbers 

 of Such tests are in progress to establish 

 confidence in specifying these limitations. 

 This is especially true of critical levels 

 of dissolved oxygen. 



DISCUSSION AND CONCLUSIONS 



Some innovations have been utilized 

 in the construction and use of the standpipe 

 at Mill Creek, California. The pipe was 

 designed specifically to make available a 

 systematic history of the influence of 

 environment on the spawn of the king salmon 

 in natural stream gravel through the period 

 of incubation. After the experience in 

 which the methods described in the text have 

 been developed, the authors feel that the 

 extended sampling and recording approach has 

 advantages for stream-management work. 



To make this method effective, we have 

 made several special adaptations. One of 

 these is the use of noncorroding materials 

 for prolonged submergence of the standpipe 

 in water. Another is the use of a 2-part 

 instrument, the permanent part protruding 

 only slightly above the gravel and being 

 capped between readings. A third is the 



TABLE 5 SEEPAGE AND DISSOLVED OXYGEN VALUES COMPARED WITH SURVIVAL OF KING SALMON SPAWN AT MILL CREEK 



DURING THE 1956-1957 INCUBATION SEASON 



«v. 19. 1956 

 i Survival 



Otc. 13, 1956 

 v«l. D.o. 

 ft/hr. pp» *> 



* 3ur- 

 Tlval 



J«ii. 7, 1957 

 v»l. D.o. % Sur- 



ft/hr. H» °F rtv«l 



jaa. }1, 1957 

 v«l. D.o. * Sur- 



ft/br pi» ^ ylTOl 



Ifcr. 7, 1957 

 ■/•I. D.O. « Sur- 



ft/hr. pi» °T vlvml 



StUMl- 



Plp»i 



1 8^ 



? 9k^ 



3 87.0 



1.13 

 a.56 



6.7 



Bcvly astcbad Alcvtn 



UJi.O 89-5 2.56 11.1 Wt.O 71.^ .21 6.1 36.5 31.0 



Wt.O 65-0 3.1*7 10.9 1*3.0 81*. .87 6.5 36.5 22.5 



w*.o 81.5 3.52 U.J 1*3.0 79-5 2.1*0 9-3 36.5 68.0 



2:1 



22.0 



50.0 70.0 1.68 9J* U7.0 92.0 ^ 



50.0 71-5 2.16 10.7 1*7.0 95.5 ^ 



50.0 80.5 - 10.5 U7.0 89.5^ 



MDto I^r. 1 

 2 

 3 



81*. 5 

 61.0 



2.52 I*. 7 

 330 '•.9 

 2.96 ''■5 



2.60 3.2 1*2.0 89.7 

 3.32 3.6 1*2.0 60.2 

 1.1*1 5.3 l»2.0 83.6 



I. F. MU a. 



Rim* I 



1 Sii 



2 



3 95-0 



t* 



5 950 



3.62 

 l.k6 

 O.JO 

 0.27 

 2.70 



5.5 

 6.9 

 8.6 

 6.1* 

 6.3 



1*1*. &..0 

 1*1*. 



1*3.0 jro 



1*1*. 



1*1*. 87.0 



3.91 

 1.1.7 

 2.32 



0.23 

 1-35 



85.5 



10.5 

 9.1* 



39.0 

 39.0 

 39.0 

 39.0 

 39.0 75.0 



71.0 



2.73 

 1.25 



:.u 



0.15 

 3-95 



u.o 

 6.9, 

 10.9 



31*. 

 31*. 

 31*. 

 3*.o 

 31*. 



66.0 

 26.5 

 60.0 



I*. 6 

 3.8 



50.0 

 50.0 

 50.0 

 50.0 

 50.0 



1/ I)>plu)t«d vltb «0g« of ttmt 

 Ifcreb 7, 1957 d»t* for WU 



lot vb«a lov mtcr killad orl|tln»I pl*nt. 



Crack and Sacna«nto Plv«r uaobt&lokble bacuue of hl^ iMt«r. 



18 



