44 BULLETIN OF THE BUREAU OF FISHERIES 



natural conditions. The maximum productivity also will fluctuate widely, though 

 not necessarily in proportion to the actual abundance of fish, as it would seem probable 

 that a larger percentage could be taken in times of relative abundance than in times 

 of relative scarcity. This available surplus, which can be taken for commercial use, 

 will, then, on a percentage basis, fluctuate even more widely than will the general 

 abundance. In the early stages of the development of a fishery the number of fish 

 taken remains so far below the available supply that it is aff'ected less seriously by the 

 fluctuations in abundance. In times of scarcity the fishing effort may be adjusted 

 readily, so that the annual catches will not show nearly as violent fluctuations as 

 those of real abundance. When, however, the fishery has developed to the point 

 where the actual take of fish exceeds the available surplus and approaches the total 

 supply, it will be impossible to adjust the fishing effort so that in times of scarcity 

 the annual catch may be maintained and wider fluctuations in productivity will 

 appear. If, for instance, the annual catch of a fishery over a period of time is only 

 one-tenth of the total supply, the great preponderance of the total supply will act 

 as a buffer, so to speak, between the fluctuations in total abundance and the actual 

 catch, and adjustments of the fishing effort will serve to maintahi the catch at a fairly 

 constant level. However, as the annual catch approaches closer and closer to the 

 total abundance, until, for example, 75 per cent of the total supply is taken annually, 

 it will become increasingly difficult to maintam the catch at a constant level and it 

 will reflect more and more the inequalities in abundance. When this stage of develop- 

 ment has been readied, therefore, it is logical to expect that the fluctuations in 

 annual catches will become more violent, and we may assume that a fishery that 

 shows such violent fluctuations has at least reached a point where more intensive 

 exploitation will cut into the reserve necessary for the maintenance of the resource. 



The Alaska salmon fisheries apparently had reached this stage at least by 1918, 

 when the relatively smooth curve of development was replaced by the wide fluctua- 

 tions of the succeeding years. The general level for the past 10 or 12 years has been 

 around 4,500,000 or 5,000,000 cases, but if the hypothesis given above is correct it 

 would seem that this is more than the resource can stand without injury. Perhaps 

 the general level should be maintained at 3,500,000 or 4,000,000, but any such state- 

 ment in reference to the total pack is necessarily very indefinite, as the total pack 

 includes five species of salmon and an indefmitely large number of races taken throiigh- 

 out the vast extent of the Territory. In the more detailed analyses of separate 

 species and localities, which follow, we shall attempt to show the fluctuations in the 

 numerous components that together make up the total pack. 



The studies of Alaska salmon statistics iipon which this report is based were 

 begim in 1925. The passage of the act of June 6, 1924, had placed full responsi- 

 bility for the care and preservation of the Alaska fisheries upon the Department of 

 Commerce. To fulfill this responsibility adequately, a knowledge of the trends and 

 fluctuations in the fishery was imperative, and this report is the result of an effort 

 to collect and analyze the available data on the salmon fisheries of Alaska. Fortu- 

 nately, the bureau possessed detailed yearly statistics in the form of sworn annual 

 reports sxibmitted since 1904 by each firm or individual packing salmon in the Ter- 

 ritory. These reports give, among other things, the number of salmon of each species 

 caught, the locality where the capture was made, and the kind and amount of gear 



