H.IORT and SCHRKCK: PHKNOTYPIC DIFFKRKNCKS AMONC (OHO SALMON 



FIGURE 3.— Transferrin gene frequencies of wild coho 

 salmon stocks for 1976 and 1977 brood years. Stocks are 

 arranged from north to south. Bars represent 95% con- 

 fidence intervals and the sample sizes are above the bars. 

 Location codes are as in Figure 1. 



23 54 50 28 



UJ 



Ld 



< 



UJ 



c_> 

 or 



UJ 

 0- 



»" m s 



Table 6.— Statistically significant correlation coefficients 

 between the characteristics of the coho salmon stocks and the 

 environmental characteristics of their respective stream 

 systems, r = 0.28 at a = 0.05 and 0.37 at a = 0.01. 



Characteristics 



coast hatchery stocks (Fig. 2). The gene fre- 

 quencies of hatchery stocks may have been 

 altered by earlier importing of stocks with dif- 

 ferent gene frequencies, or by disease epizootics. 

 If fish with certain transferrin genotypes have 

 different resistances to diseases, and if epizootics 

 are more severe because of the higher densities of 



ttOr 



ar>- 



60-- 



< 



;< 40- • 



g *H" 



10 



BASIN AREA (Ln SO. Ml.) 



Figure 4.— Transferrin gene frequencies for wild and 

 hatchery coho salmon stocks arranged by basin area, in ln 

 square miles. 



fish in hatcheries, then the transferrin gene fre- 

 quency of a given year class could be altered 

 without affecting the other two year classes. 



The phosphoglucose isomerase variant (Table 

 7) was present only in samples from Oregon 

 stocks — particularly those from the northern 

 Oregon coast. May ( 1975) reported this variant in 

 Washington stocks. 



Similarity of Stocks 



The groups of stocks of coho salmon found to 

 be most similar by the agglomerative cluster 

 analysis (Fig. 6) were composed of northern 



113 



