FISHERY BULLETIN: VOL. 70, NO. 1 



There are, however, a number of different scale 

 types among those that do occur. 



Most fish from the Copper River, Yakutat, and 

 Petersburg areas have scales much like those 

 of Chignik and Cook Inlet. The scales are char- 

 acterized by small- to medium-sized freshwater 

 zones in which most of the circuli are broken 

 or irregular. The first ocean zone of these scales 

 averages slightly more circuli than those of the 

 Cook Inlet area, however, and the circuli are 

 more closely and evenly spaced. 



A second type of scale from this area has a 

 large freshwater zone with numerous circuli. 

 These scales are found in small numbers in var- 

 ious areas from the Copper River to the Columbia 

 River and are shown in Plate 14. 



Scales showing this freshwater age from the 

 Nass, Skeena, and Fraser Rivers and some from 

 the Nimpkish River (the British Columbia fish) 

 usually have moderately large, well-marked 

 freshwater zones. Usually the broken circuli are 

 confined to the winter checks. In the first ocean 

 zone, fish from the Nimpkish River have more 

 numerous, regular, evenly spaced circuli than 

 those from any other area. Scales of these 

 British Columbia fish are relatively easy to in- 

 terpret and often difl'er from Bristol Bay scales 

 only in having, on the average, a few more circuli 

 and more evenly spaced circuli in the first ocean 

 zone. The scales tend to have a less open appear- 

 ance than those of Bristol Bay fish. 



The few scales of this age group of sockeye 

 salmon from the Ketchikan area occur in at 

 least three types: (1) scales like those of the 

 Copper River-Petersburg area, like the one pic- 

 tured on this plate from a fish taken near Peters- 

 burg, (2) scales with a larger freshwater zone 

 like those from Nass River fish, and (3) very 

 few scales with very large freshwater zones like 

 the one pictured from the Copper River on Plate 

 14. In the Ketchikan area there are many small 

 streams that produce some sockeye salmon. In 

 addition, many channels and bays serve as water- 

 ways through which fish migrate to other areas. 

 Thus it is possible that many of the Petersburg 

 and Nass type scales taken in this area may 

 actually be from fish migrating to the Petersburg 

 area or the Nass River. 



Most fish of this age found in the Columbia 



River have large freshwater zones varying from 

 those like the one pictured on this plate to ones 

 with very large freshwater zones, shown on 

 Plate 14. On all of these Columbia River scales, 

 the freshwater circuli are well marked and well 

 separated, even if many are broken or irregular. 

 The circuli of the first ocean zone of these scales 

 are also usually well marked; they are evenly 

 and widely spaced. The zone averages some- 

 what fewer circuli than on scales from the Nimp- 

 kish, Nass, Skeena, and Fraser Rivers but more 

 than on the scales from Bristol Bay fish. An 

 area of wider spaced circuli may occur at any 

 position within the first ocean zone, but the dif- 

 ference between the widely spaced and the closely 

 spaced circuli is not as great as in the Bristol 

 Bay scales. 



Fish of this freshwater age are rare in Rivers 

 Inlet. These scales can be identified as typical 

 Rivers Inlet type from their appearance (see 

 Plate 14). 



Areas with Some Distinctive Scales (Plate 14) 



In most years a number of areas from'Kodiak 

 Island to the Columbia River have some fish 

 with very large freshwater zones on their scales, 

 but except for the Nimpkish River, there were 

 not enough fish to provide data for frequencies 

 of the number of circuli. Only slight diflferences 

 in the freshwater zone of the fish from the var- 

 ious areas can be found. 



In some years, scales from some Bristol Bay 

 and Aleutian Island fish may also have these 

 very large freshwater zones." These are not 

 pictured on this plate because they resemble the 

 ones shown from the Copper River to the Co- 

 lumbia River, and they do not occur in most 

 years. 



Differences in the number and character of 

 the circuli in the first ocean zone of the scales 

 from fish of the diflferent areas, however, offer 

 an indication of the locality from which the fish 

 came. The largest number of circuli in this zone 

 tends to be on scales of the Nimpkish River sock- 

 eye salmon; fewer circuli (and more broken 



" A number were observed in Bristol Bay samples for 

 1970. 



176 



