506 



AbStrdCt.— Chinook salmon. Onto- 

 rhynchus tshawytscha, transplanted 

 from the Sacramento River, California, 

 to the Waitaki River catchment of New 

 Zealand at the turn of the century rap- 

 idly colonized many South Island riv- 

 ers. Allozyme genotype and mtDNA 

 haplotype frequencies were obtained 

 from tissue samples from chinook 

 salmon in Waitaki, Rakaia, Waimaka- 

 riri, and Clutha rivers in New Zealand 

 and compared with data from popula- 

 tions in the Sacramento River to pro- 

 vide further information on the origin 

 of the NZ populations and to ascertain 

 the genetic changes that have taken 

 place since the transplant. Neither 

 allozyme nor mtDNA unequivocally 

 identified an ancestral "seasonal" run 

 (fall, winter, or spring) for the NZ chi- 

 nook salmon. Sacramento River samples 

 collectively diverged from the NZ 

 samples at allozyme loci, and mtDNA 

 indicated greater similarity between 

 NZ samples and fall-run rather than 

 winter and spring runs from the Sac- 

 ramento River. Significant variation 

 was detected by mtDNA analysis be- 

 tween only two of the four populations 

 within NZ, one of which has been land- 

 locked by an impassable dam since 

 1956. The allozyme data identified sig- 

 nificant variation within NZ, although 

 less than has been documented among 

 Sacramento River populations. The NZ 

 populations also showed less genetic 

 diversity (mean number of alleles per 

 locus, proportion of loci that were poly- 

 morphic, and mean heterozygosity) 

 than the Sacramento River popula- 

 tions. These lower values are consistent 

 with a population bottleneck in the first 

 generations after transplantation into 

 the Waitaki River catchment and with 

 founder effects during the formation of 

 populations in the other NZ rivers. The 

 combination of genetic differences and 

 phenotypic variation among the NZ 

 populations indicates that Pacific 

 salmon populations can develop rapidly 

 after colonizing suitable habitat. 



Origin and genetic structure of 

 Chinook salmon, Oncorhynchus 

 tshawytscha, transplanted from 

 California to New Zealand: allozyme 

 and mtDNA evidence 



Thomas R Quinn 



School of Fisheries, University of Washington 



PO Box 357980 



Seattle. Washington 98195 



Jennifer L. Nielsen 

 Christina Gan 



United States Department of Agriculture. Forest Service 

 Pacific SW Research Station 

 800 Buchanan St., West Annex 

 Albany. California 94710 



and 



Hopkins Marine Station, Stanford University 

 Pacific Grove, California 93950-3094 



Martin J. Unwin 



National Institute of Water and Atmosphere 

 PO Box 8602, Chnstchurch, New Zealand 



Richard Wilmot 

 Charles Guthrie 



National Marine Fisheries Service Auke Bay Laboratory 

 I 1 305 Glacier Highway Juneau, Alaska 99801 



Fred M. Utter 



School of Fisheries, University of Washington 



PO Box 357980, 



Seattle, Washington 98195 



Manuscript accepted 15 April 1996. 

 Fishery Bulletin 94:506-521 ( 1996). 



Salmonids display great interpopu- 

 lation variation in life history traits, 

 structure, behavior, and other char- 

 acteristics, reflecting differences in 

 rearing conditions and genetic ad- 

 aptation to local environments 

 (Ricker, 1972; Saunders, 1981; Tay- 

 lor, 1991). Fisheries management 

 attempts to be population-specific, 

 reflecting the importance attached 

 to these adaptations (e.g. McDonald, 



1981 ). The past few years have seen 

 a series of reports documenting 

 losses of discrete Pacific salmon 

 populations in the U.S. Pacific 

 Northwest (Nehlsen et al., 1991; 

 Alkire 1 ) and in particular states 

 (Washington: Palmisano et al. 2 ; 



1 Alkire, C. 1993. The living landscape. 

 Vol. 1: Wild salmon as natural capital. Vol. 

 2: Pacific salmon and Federal lands. The 

 Wilderness Society, Seattle, WA, 174 p. 



