FISHERY BULLETIN: VOL. 70, NO. 1 



Table 2. — Geographical areas wliere scales were taken from sockeye salmon. (Scales are available at the Na- 

 tional Marine Fisheries Service, Northwest Fisheries Center, Seattle, Wash.) 



' Samples from the five major Bristol Bay rivers were taken each year since 1954. 

 but there is only one sample for some of the less important areas. 

 - Additional samples were taken, but numbers of scales were small. 



There ore samples for most other areas for a number of years. 



""3.4 occur, but in most localities most fish are 

 in affe groups 1.2, 1.3, 2.2, and 2.3. 



The number of years spent in fresh water 

 varies within and between many spawning areas 

 and influences many of the scale characters 

 (Mosher, 1963, 1968). Only a few adult fish 

 of age 0. or 4. are found, some fish of age 3. are 

 found in a few areas, but fish of age 1. and 2. are 

 present in substantial numbers in most areas. 

 Table 3 shows the percentage freshwater age 

 composition of sockeye salmon in stream samples 

 (except as noted) from areas around the North 

 Pacific Ocean available at the NMFS Northwest 

 Fisheries Center. 



Many features of sockeye salmon scales 

 can be used in racial studies. Scientists at 

 the NMFS Northwest Fisheries Center in Se- 

 attle have examined about 50 diff"erent features 



■^ Age designation follows the European system, Koo 

 (1962a) : the number of winters the fish spent in fresh 

 water since hatching, a decimal point, and the number 

 of winters the fish spent in the ocean (see Mosher, 19G8, 

 p. 259 and 262). 



such as counts of circuli, measurement of zones 

 and portions of zones, and various ratios based 

 on these counts and measurements; but only 

 scale characteristics with the greatest differ- 

 ence between Kamchatkan and Bristol Bay stocks 

 have been described in our publications (Mosh- 

 er et al., 1961; Mosher, 1963, 1968; Anas, 

 1964; Anas and Murai, 1969). In all of our 

 studies — published and unpublished — the best 

 features for racial studies have been in the fresh- 

 water and first ocean zones of the scale. 



Because of the large number of Asian and 

 North American spawning areas and the large 

 number of age groups in some areas, it is evi- 

 dent that space is not available for examples of 

 scales representative of each area and age group 

 over the geographic range of the species. Scales 

 from numerous areas are similar in many char- 

 acters; consequently I will group together scales 

 from fish of more than one stock or spawning 

 area that have a relatively similar ap])earance. 



The number of circuli in the freshwater and 

 first ocean zones (counted as indicated on p. 36 



144 



