FISHERY BULLETIN: VOL. 70, NO. 1 



Asian fish can be considered of North American 

 origin and classified accordingly. 



In the area east of lonpr 175° W into the Gulf 

 of Alaska, the number of circuli and the general 

 api^earance of the freshwater and first ocean 

 zones of most scales of age 1. fish can be evalu- 

 ated and the most probable area of origin can 

 be determined by comparison with the scales in 

 Plates 4 to 7. 



Rivers Inlet scales can be identified easily by 

 their appearance. They stand out distinctly 

 from the scales of other areas in all freshwater 

 ages because of the fine-textured circuli of the 

 freshwater and first ocean zones (Plates 1, 9, 

 and 14). 



Some scales may be found that have large 

 freshwater zones. In age 1. these are most 

 likely from Unalaska or Kodiak Island, Fish 

 Creek, or the Ximpkish River (Plate 8) . In age 

 2., they may be from Kodiak Island, Fish Creek, 

 Copper River, the Ketchikan area, the Nimpkish, 

 Fraser, or Columbia Rivers (Plate 14). None 

 of these stocks are abundant in these ages, but 

 some are taken at times. The number of circuli 

 in the first ocean zone may assist in determining 

 from which specific area the fish originated. 



Migration routes to the various streams have 

 not yet been determined for most stocks, but 

 certain indications are given by tagging studies. 

 Research by the Canadians for the INPFC (Fish- 

 eries Research Board of Canada, 1967a, 1967b) 

 shows that fish recovered in the Rivers Inlet- 

 Fraser River area tend to have been tagged 

 farther southward in the Gulf of Alaska in 

 spring and summer than those recovered from 

 the Cook Inlet and Copper River areas. Fish 

 recovered from Bristol Bay tend to have been 

 tagged farther westward than those recovered 

 from the Rivers Inlet-Fraser River areas. Hartt 

 (1962, 1966) and Kondo et al. (1965) indicated 

 that many Bristol Bay fish move westward along 

 the south side of the Alaska Peninsula and the 

 Aleutian Islands, turn north through the passes, 

 and then migrate eastward into Bristol Bay. 



Thus if the scale (age 2.) under study has a 

 large freshwater zone and a large number of 

 circuli in the fir.st ocean zone (over 27 circuli) 

 and was taken in the southern part of the Gulf 

 of Alaska, it would be most likely from the Nimp- 



kish River (Plate 14) . If the scale had 23 to 27 

 circuli in the first ocean zone and was taken in 

 the northern part of the Gulf, it would probably 

 be from Cook Inlet, Kodiak Island, or Fish Creek; 

 if it had 28 to 30 circuli, it would probably be 

 from the Copper River or southeastern Alaska 

 (Plate 14) ; and if it had less than 23 circuli, 

 it would probably be from a Bristol Bay fish 

 (Plate 11), or possibly from a spawning stream 

 on Adak or Unalaska Island (Plate 12)) if 

 caught near the Aleutian Islands. 



In age 3. sockeye salmon, a scale with a large 

 freshwater zone and about 26 circuli in the first 

 ocean zone indicates most likely a Kodiak Island 

 fish; less than 23 circuli, Bristol Bay or Unalaska 

 Island origin; and over 30 circuli, Nimpkish Riv- 

 er origin (Plate 16) . A scale with a very small 

 freshwater zone and 25 to 28 circuli in the first 

 ocean zone indicates a fish probably from the 

 Copper River or southeastern Alaska (Plate 16) . 



In age 0. fish, aside from the Rivers Inlet fish 

 which are distinguishable by their compact, fine- 

 textured first ocean zone (Plate 1), the number 

 of circuli in the first zone oflfers the best indi- 

 cation of area of origin : a few circuli ( 20 to 25 ) , 

 Bristol Bay; a large number (over 34), south- 

 eastern Alaska southward; or an intermediate 

 number (26 to 34), the area from Bristol Bay 

 to southeastern Alaska (Plate 1). 



In age 4., any fish found in the Gulf of Alaska 

 will most likely be from Kodiak Island (Plate 

 17) . If the scale is from a fish taken near the 

 Aleutian Islands and has relatively few circuli 

 in the first ocean zone, it may be from a stream 

 on Attu or Adak Island (Plate 17) or from 

 Bristol Bay. 



South of lat 50° N in the southern Gulf of 

 Alaska, the intermingling of stocks may be com- 

 plex. Very few fish have been tagged in this 

 area; catches are very small as a rule, and con- 

 sequently little is known about these fish. Study 

 of their scales oflf"ers the best means of identi- 

 fying their origin and determining other features 

 of their life history. 



Evidence from fishing by United States, Jap- 

 anese, and Canadian research vessels south of 

 lat 50° N in the late autumn, winter, and early 

 spring indicated that sockeye salmon of many 

 stocks may be present over a wider area to the 



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