FISHERY BULLETIN: VOL. 70, NO. 1 



growth of scales from other areas (compare 

 these photographs with those of the Fish Creek 

 type on Plate 8). The second ocean zone is of 

 typical ocean growth — heavy textured, well- 

 spaced circuli. This zone, unlike that on scales 

 from other areas, is usually wider than the first 

 ocean zone. Often the winter check between 

 the first and the second ocean zones is diffuse 

 and indistinct. 



The whole scale shows two large areas of con- 

 trasting texture: the freshwater and first ocean 

 zones of fine-textured circuli and the second and 

 subsequent ocean zones with coarse-textured 

 circuli of typical ocean growth. On the scales 

 from fish of other areas there is a difference 

 in texture, but the zone of fine texture, the fresh- 

 water growth, is relatively small; and the coarse- 

 textured portion of the scale, the entire ocean 

 growth, is the major portion of the scale. 



In the Nimpkish River, some of the fish 

 of this age have scales of Rivers Inlet type 

 (secondary mode at 12 circuli in column 20 of 

 Table 4) . These fish generally have a few more 

 circuli in both the freshwater and first ocean 

 zones than the fish from Rivers Inlet, and the 

 circuli are also usually less broken and irregular 

 than those from Rivers Inlet. The difference 

 in texture, however, between the first and sec- 

 ond ocean zone is typical of Rivers Inlet type 

 scales. 



Most of the fish from Rivers and Smith Inlets 

 have scales of this type. In representative sam- 

 ples the following typical Rivers Inlet scales were 

 found: 



(Area and year) 

 Rivers Inlet, 1958 



River.s Inlet, 196.3 

 Smith Inlet, 1960 

 Smith Inlet, 1961 



Percentage of 

 Rivers Inlet type 



126 of 156 fish (76.2%) (Manzer, 



Bilton, and Mosher, I960)' 

 374 of 377 fish (98.4%) 

 123 of 132 fish (93.2%) 

 246 of 270 fish (91.1%) 



These percentages approximate the range of 

 typical Rivers Inlet type scales in this area. The 



few scales that are not typical of fish of these 

 areas usually resemble scales of the Skeena or 

 Nass Rivers; consequently they still are in 

 British Columbia. 



Only an occasional scale from the other areas 

 (Cook Inlet to the Fraser River) has the appear- 

 ance of a Rivers Inlet scale. In these few cases, 

 the number of circuli in the first ocean zone is 

 usually less than that of the Rivers Inlet fish.' 



In a test of 300 unlabeled scales from many 

 areas over the range of the species set up by an 

 assistant, I correctly identified 63 out of 64 

 Rivers Inlet scales. This indicates that these 

 scales are indeed distinct and can be identified 

 from their appearance with a high degree of 

 accuracy. 



The Rivers Inlet area is a good producer of 

 sockeye salmon. In most years more than 1 mil- 

 lion fish are caught there. The Nimpkish River 

 is a small producer, but escapements of 150,000 

 and 70,000 fish were recorded in 1957 and 1958, 

 respectively (Henry, 1961). 



Rivers Inlet type scales have been observed 

 widely in oflFshore samples (Manzer et al., see 

 footnote 7; Mosher et al, 1961). 



AGE 2., ASIA (Plate 10; Tables 6 and 7) 



Representative scales of sockeye salmon from 

 the Kamchatka, Ozernaya, and Bolshaya Rivers, 

 the Okhotsk Sea, and Lakes Blizhnee and Dalnee 

 are shown on this plate. Like those of age 1., 

 scales from these fish, except Lakes Blizhnee and 

 Dalnee, do not differ much between areas. The 

 freshwater zone is of moderate size, sometimes 

 with plus growth. The circuli are close together 

 and many are broken or irregular. (See Table 9 

 for a summary of freshwater scale characters of 

 Asian sockeye salmon from Krogius, 1958.) 



The first ocean zone of scales from these fish 

 also do not differ significantly and are similar to 

 the same zone of the scales of the age 1. fish from 

 the same areas. Usually the circuli are evenly 

 and moderately closely spaced and lack the open 



' Manzer, J. I., T. H. Bilton, and K. H. Mosher. 1960. 

 The ocean distribution of sockeye salmon originating in 

 Rivers and Smith Inlets. Fish. Res. Board Can. (Na- 

 naimo, B.C.) and Bur. Commer. Fish. (Seattle, Wash.) 

 (INPFC Doc. 407), 5 p. (Processed.) 



* From this point on, the term "Rivers Inlet" also 

 includes Smith Inlet and the Rivers Inlet type scales 

 of fish from the Nimpkish River. 



174 



