GENETIC VARIATION IN CHINOOK, ONCORHYNCHUS TSHAWYTSCHA, 



AND COHO, O. KISUTCH, SALMON FROM 



THE NORTH COAST OF WASHINGTON 



R. R Reisenbichler' and S R Phelps^ 



ABSTRACT 



We used starch-gel electrophoresis to genetically characterize the populations of chinook salmon, 

 Oncorhynchus tshawytscha . and coho salmon, O. kisutch, in the major drainages of the north coast 

 of Washington (the Quillayute, Hoh, Queets, and Quinault Rivers). Of 55 loci examined for elec- 

 trophoretically detectable variation, 6 were polymorphic (frequency of the common allele was less 

 than 0.95) in chinook salmon and 3 in coho salmon. Statistical tests of interdrainage and intra- 

 drainage variation for coho salmon were tenuous because most of the fish examined were from a 

 single year class so that we could not account for variation among year classes. Nevertheless, these 

 tests suggested that distinct stocks of coho salmon exist within drainages, and that variation was not 

 significantly greater am6ng drainages than within drainages. Interdrainage variation for wild chi- 

 nook salmon was not significant. The data suggested that summer chinook salmon were elec- 

 trophoretically different from fall chinook salmon, and the hatchery populations of chinook salmon 

 were distinct from wild fish. A hatchery population developed primarily from north coast fish was 

 electrophoretically more similar to wild chinook salmon than were the others. 



Effective conservation and management of natu- 

 ral organisms require protection of the genetic 

 resources (genes, gene combinations, gene pools) 

 of these organisms (Altukhov 1981; Frankel 

 1983). Conservation of anadromous salmonids 

 from the north coast of Washington (the area 

 from the Quinault River to the Strait of Juan de 

 Fuca) is receiving national attention because 

 many of these fish spawn or rear in Olympic Na- 

 tional Park, and the United States Congress has 

 directed that the natural resources of National 

 Parks be conserved. Olympic National Park is the 

 only natural area administered by the National 

 Park Service outside Alaska with substantial 

 numbers of native anadromous salmonids. There 

 is also international concern for conservation of 

 natural (including genetic) resources in Olympic 

 National Park, as indicated by inclusion of the 

 park in the International Biosphere Reserve Pro- 

 gram (Franklin 1977). 



The present study was initiated to genetically 

 characterize the populations of chinook salmon, 

 Oncorhynchus tshawytscha , and coho salmon, O. 

 kisutch , from the major drainages of the north 



lU.S. Fish and Wildlife Service, Seattle National Fishery Re- 

 search Center, Building 204, Naval Station, Seattle, WA 98115. 



'■^U.S. Fish and Wildlife Service, Seattle National Fishery Re- 

 search Center, Building 204, Naval Station, Seattle, WA 98115; 

 present address: Washington Department of Fisheries, Room 

 115, General Administration Building, Olympia, WA 98504. 



Manu.scnpt accepted July 1987. 



FISHERY BULLETIN VOL 85, NO. 4. 1987. 



coast: the Quillayute, Hoh, Queets, and Quinault 

 Rivers (Fig. 1). Coho salmon from two other 

 streams in northwestern Washington (the Sno- 

 homish River and Snow Creek) and chinook 

 salmon from Elwha Hatchery and the Wynoochee 

 River were also sampled to enhance our perspec- 

 tive for examining north coast fish. Chinook and 

 coho salmon are native to the west coast of North 

 America from California to Alaska (Scott and 

 Crossman 1973) and are the only species of 

 Pacific salmon that are abundant in each of the 

 major north coast drainages. Starch-gel elec- 

 trophoresis was used to genetically characterize 

 the fish. 



Our objectives were 1) to develop a baseline set 

 of allele frequency data; 2) to determine whether 

 allele frequencies varied among major drainages; 

 3) to determine the degree of genetic structuring 

 in coho salmon within major drainages; 4) to de- 

 termine whether summer chinook salmon are 

 electrophoretically distinct from fall chinook 

 salmon; and 5) to determine whether hatchery 

 populations of chinook salmon are electrophoreti- 

 cally distinct from wild (i.e., naturally spawned) 

 fish. 



We could not examine genetic structuring in 

 chinook salmon within major drainages because 

 wild adults were sampled in the lower portions of 

 the rivers and thus their destinations within the 

 major drainages were unknown, and samples of 



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