the present study the size of females did 

 not strongly influence their distribution. Fe- 

 males tagged August 20 and 21 demonstrated 

 a downstreann "shift" in their distribution 

 on the spawning ground in the latter half 

 of the spawning period in 1963. This change 

 in distribution occurred after streann dis- 

 charge increased from 0.3 to 3.0 m. /sec. 

 or more; hence, the increased turbulence of 

 the water in the upper area, which has a 

 steep gradient, could have caused late spawners 

 to seek the less turbxilent water in down- 

 streann low-gradient areas. 



If density of spawners is high in the upper 

 area of Sashin Creek only when the escape- 

 ment is large, it could be the result of 

 crowding in the middle and lower areas, 

 which might cause the spawners to "over- 

 flow" into the upper area. This behavior 

 could contribute to relatively low survival 

 of the population in years when spawners 

 are scarce and to relatively high survival 

 in years when spawners are abundant. Data 

 for 22 broods of pink salmon in Sashin Creek 

 show survival of fry from the 11 smaller 

 broods to average 4.5 percent of the potential 

 egg deposition and survival from the 11 

 larger broods to average 8.2 percent (table 13). 

 Although these data demonstrate that low 

 abundance of spawners offers no advantage 

 in terms of an increased percentage survival, 

 the average survival of the progeny of the 

 11 larger escapements was not significantly 

 greater than that of the 1 1 smaller ones 

 (t_ = 1.27; 20 degrees of freedom). 



The supposition that only highly productive 

 spawning beds are used in years in which 

 escapements are small is to be questioned; 

 when escapements are small, the more pro- 

 ductive spawning areas of Sashin Creek are 

 not always used. This behavior cannot be ex- 

 plained fully at this time. Yet if predation is an 

 important cause of mortality in the upper area, 

 mortality could increase in that area as the 

 size of the population decreases. If so, it could 

 be beneficial for small escapements to spawn in 

 the downstreann areas even though physical 

 characteristics for growth of embryos and 

 alevins might be less favorable. Additional re- 

 search on this problem is needed. 



Behavior traits that affect distribution of 

 spawners should receive consideration in the 

 management of pink salmon. Because of possi- 

 ble unequal distribution of spawners, it might be 

 desirable or necessary to provide escapements 

 in excess of those which would be required if 

 spawners were distributed uniformly. Crowding 

 on certain spawning beds may cause some 

 spawners to leave and use spawning beds that 

 are more favorable for developing embryos and 

 alevins. 



ACKNOWLEDGMENTS 



Robert Coats, Clark Fontaine, Dennis Shep- 

 perd, and Ralph Wells assisted in the field 

 studies. 



LITERATURE CITED 



DAVIDSON, F. A., ELIZABETH VAUGHAN, 

 S. J. HUTCHINSON, and A. L. PRITCHARD. 

 1943. Factors influencing the upstream 

 migration of the pink salmon ( Oncor- 

 hynchus gorbuscha ). Ecology 24: 

 149-168. 

 FABRICIUS, ERIC, and KARL- JAKOB 

 GUSTAFSON. 

 1954. Further aquarium observations on 

 the spawning behavior of the char, 

 Salmoalpinus L. Inst. Freshwater Res., 

 Drottningholm, Rep. 35(1953):58- 104. 

 HUNTER, J. G. 



1959, Survival and production of pink and 

 chum salmon in a coastal stream. J. 

 Fish. Res. Bd. Can. 16:835-886. 



KAGANOVSKII, A. G. 



1949. Nekotorye voprosy biologii i dinamiki 

 chislennosti gorbuschi. (Some prob- 

 lems of the biology and population 

 dynamics of pink salnnon.) Izv. Tikhook. 

 Nauch.-Issled. Inst. Rybn Khoz. Okea- 

 nogr. 31:3-57. (Translation in Pacific 

 Salmon, Nat. Sci. Found, and U.S. Dep. 

 Int., Israel Program for Scientific 

 Translations, Jerusalem.) 



McDonald, j. g. 



1960. A possible source of error in as- 

 sessing the survival of Pacific salmon 

 eggs by redd sampling. Can. Fish Cult. 

 26:27-30. 



McLARNEY, WILLIAM O. 



1964. The coastrange sculpin, Cottus aleu- 

 ticus : structure of a popxilation and 

 predation on eggs of the pink salmon, 

 Oncorhynchus gorbuscha . M. S. Thesis, 

 Univ. Mich., Ann Arbor, 83 p. 



McNeil, william j. 



1962. Variations in the dissolved oxygen 

 content of intragravel water in four 

 spawning streams of southeastern 

 Alaska. U.S. Fish Wildl. Serv., Spec. 

 Sci. Rep. Fish. 402, 15 p. 



1964a. Redd superimposition and egg ca- 

 pacity of pink salmon spawning beds. 

 J. Fish. Res. Bd. Can. 21:1385-1396. 



1964b. A method of measuring mortality 

 of pink salmon eggs and larvae. 

 U.S. Fish Wildl. Serv., Fish. Bull. 

 63:575-588. 



1966. Effect of the spawning bed environ- 

 ment on reproduction of pink and chum 



11 



