Figure 8.- -Generalized distribution pattern of tag returns from king and silver salmon 

 and steelhead trout tagged at sea from 1956 to 1959. 



high seas fleet. Red salmon are overwhelmingly American 

 (Bristol Bay) across the full length of the Aleutians. Chums 

 are a mixture, and Asian fish probably predominate in areas 

 west of 170° West longitude. Pinks are abundant and over- 

 whelmingly Asian in odd years, whereas in even years this 

 species is scarce, but principally American in origin. 



The problem of boundaries of distribution of Asian and 

 American salmon is thus made more complex by the dis- 

 similar distribution of the several species. These distri- 

 butions can be expected to vary annually in accordance with 

 relative abundance and perhaps according to varying migra- 

 tion patterns, oceanographic conditions, and the like. 



Canadian and United States regulations prohibit all szilmon 

 fishing, except some trolling, on the high seas. This permits 

 much more effective regulation since intensity of fishing 

 upon rtms to individual rivers may be regulated according 

 to size of runs. Depleted stocksmay be protected, and healthy 

 runs fished more. High seas harvesting permits no such indi- 

 vidual controls and cilso takes many immature salmon. 



This paper presents a brief outline of results to date of 

 one phase of a large research program on Pacific salmon at 

 sea. In addition to providing data for the purposes of the 

 International North Pacific Fisheries Conunission, the re- 

 search is providing a wezilth of new information on the ocean 

 biology of scdmon. The saltwater life-history of salmon and 

 steelhead is proving no less remarkable than their much- 

 studied yet little-understood freshwater life-history. 



MS. 978. 5-60 

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