250 
Fishery Bulletin 106(3) 
Table 4 
Mean pairwise population F st values observed over 14 microsatellite loci for 34 chum salmon (Oncorhynchus keta) populations 
from eight regions. Regions were the following: 1) Primorye, 2) Amur River, 3) Sakhalin Island, 4) Magadan, 5) Northern Sea 
of Okhotsk, 6) West Kamchatka, 7) East Kamchatka, and 8) Northeast Russia. Boldface font indicates significant difference 
(P<0.05). A dash indicates that it was not possible to determine within-region pairwise population F st values for the Amur River 
because only a single population was sampled. 
Region 
1 
2 
3 
4 
5 
6 
7 
8 
1 
0.012 
2 
0.032 
— 
3 
0.031 
0.035 
0.020 
4 
0.026 
0.021 
0.031 
0.004 
5 
0.036 
0.036 
0.046 
0.010 
0.000 
6 
0.028 
0.028 
0.027 
0.009 
0.014 
0.006 
7 
0.026 
0.024 
0.029 
0.006 
0.011 
0.006 
0.004 
8 
0.033 
0.033 
0.041 
0.014 
0.009 
0.016 
0.014 
0.000 
Table 5 
Mean estimated contribution (%) of populations of chum salmon ( Oncorhynchus keta) in Russia for simulated mixtures. Esti- 
mates are for only a single region (correct regional estimate = 100%) and were calculated from the populations listed for each 
mixture, with each population comprising 50% (100% for Amur River) of each simulated regional mixture. Estimates were deter- 
mined from 14 microsatellite loci for eight separate regional stocks. The region designation includes percentages allocated to all 
populations within a region. Simulations were conducted with a 34-population baseline, 150 fish in the mixture sample, and 100 
resamplings in the mixture sample and baseline samples. Standard deviations are shown in parentheses. 
Mixture 
Region 
Regional estimate 
Population 
Population estimate 
1 
Primorye 
89.5(2.5) 
Avakumovka 
43.9(4.5) 
Ryazanovka 
45.5(4.5) 
2 
Amur River 
98.2(1.1) 
Amur 
98.2 (1.1) 
3 
Sakhalin Island 
94.8(1.8) 
Naiba 
55.1 (4.8) 
Tym 
39.6(4.7) 
4 
Magadan 
90.0(3.0) 
Ola 
44.3(4.5) 
Okhota 
44.0(4.1) 
5 
Northern Sea of Okhotsk 
86.9(3.1) 
Oklan 
47.8 (4.7) 
Penzhina 
39.1 (4.3) 
6 
West Kamchatka 
95.9 (2.2) 
Vorovskaya 
49.2(5.4) 
Hairusova 
43.0 (5.2) 
7 
East Kamchatka 
86.1 (3.2) 
Ossora 
43.9(4.9) 
Kamchatka 
41.2 (4.7) 
8 
Northeast Russia 
89.8(2.9) 
Anadyr 
46.5 (4.9) 
Kanchalan 
43.3(3.7) 
stock compositions indicated that accurate regional esti- 
mates of stock composition should be obtained in samples 
containing individuals from multiple regions. 
Testing of accuracy of regional estimates of stock 
composition in multiregion mixtures was conducted 
by evaluating four simulated fishery samples. Esti- 
mated stock composition of a simulated mixture con- 
taining chum salmon from Primorye, Sakhalin Island, 
the Amur River, and Magadan was within 3 % of the 
actual population composition and 4% of the regional 
composition (Table 6, mixture 1). Similar results were 
observed for a simulated mixture comprising chum 
salmon from Sakhalin Island, Magadan, the northern 
Sea of Okhotsk, and west Kamchatka, with population 
estimates within 3 % of actual composition and regional 
estimates within 3 % (Table 6, mixture 2). Estimated 
stock compositions of a simulated mixture of chum 
salmon from west Kamchatka, east Kamchatka, and 
northeast Russia were within 6 % of actual population 
composition and within 5% for regional contributions 
(Table 6, mixture 3). Regional estimated stock composi- 
tions of a more complex simulated sample of fish from 
