Teel et al : Genetic analysis of juvenile Oncorhynchus kisutch 



645 



ture estimates derived from 100 simulated mixtures were 

 used to evaluate the accuracy of estimated contributions to 

 each region with mixture sizes of 100, 300, and 500 fish. 

 We analyzed mixtures composed of fish entirely from each 

 region and also mixtures that excluded fish from regions 

 south and north of our marine sampling area. Precisions of 

 the stock composition estimates for the actual mixtures were 

 estimated by bootstrapping baseline and mixture genetic 

 data 100 times as described in Pella and Milner ( 1987). 



Stock compositions were estimated for June and 

 September-October. We also combined samples over sur- 

 veys and made separate estimates from samples of marked 

 ( fin-clipped and tagged hatchery fish ) and unmarked fish to 

 examine hatchery and wild stock compositions. However, 

 because not all hatchery fish are marked, unmarked fish 

 are a mixture of wild and hatchery fish. We therefore es- 

 timated the proportion of hatchery fish for a region in the 

 sample of unmarked fish (Pyf^) by 



where P 



MH 



RvIRm 



^U^^M 



= the proportion of hatchery fish from a par- 

 ticular region in the sample of marked fish; 



= the ratio of unmarked to marked releases in 

 a region; and 



= the ratio of unmarked to marked fish in our 

 ocean samples. 



The R,,/Rf^f for 1997 and 1998 brood years varied consider- 

 ably among regions; California coast 1.0, Klamath River to 

 Cape Blanco 0.01, Oregon coast 0.12, Columbia River 0.12, 

 southern Washington coast 0.03, northern Washington 

 coast 0.69, Puget Sound 0.43, southern British Columbia 

 0.09, and Upper Eraser River 0.80 (Lavoy'; PSMFC^). We 



PuH =(Pmh(Ru'Rm^)/(S„/SJ, 



(1) 



Lavoy, L. 2001. Personal commun. Washington Department 

 of Fish and Wildlife, Olympia, WA. 98501. 

  PSMFC (Pacific States Marine Fisheries Commission). 

 2001. Regional Mark Information System (RMIS) coded-wire 

 tag on-line database. [Available from Pacific States Marine 

 Fisheries Commission, 45 SE 82°'' Dr., Suite 100, Gladstone, 

 OR 97027-2522.1 



