36 MANAGEMENT OF HIGH SEAS FISHERIES 



of the conditions of abstention tliat tiie regulating bodies in- 

 sure the complete and full exploitation of the stocks concerned. 



(4) Sampling of the catches of halibut taken in the eastern Bering 

 Sea by United States and Canadian fishermen indicates a de- 

 cline in the average age, size, and abundance of these fish. For 

 example, in the 1960 Annual Report of the Halibut Commis- 

 sion the percentage of the catch that consisted of fish younger 

 than 12 years of age was reported to have risen from 62 per 

 cent in 1958, to 78 per cent in 1959, and 84 per cent in 1960. 

 The preponderance of young fish in the catch is in sharp con- 

 trast to Area 3 A, where fish under 12 years of age have averaged 

 55 per cent of the total catch during the past five years (IPHC, 

 1952-1961). This is the normal reaction of any stock, such as 

 the halibut, to a heavy fishery, and indicates the gradual re- 

 moval of the accumulated stock of older fish. It does not 

 necessarily indicate an inidesirable decrease in abundance, but 

 the rapidity of the decline is indicative of a very high rate of 

 removal. The fishing mortality calculated from the age com- 

 position is higher than on grounds where full utilization is 

 recognized. 



(5) Finally, as stated in Report No. 30 (IPHC, 1961, p. 20), "Re- 

 coveries (of tagged halibut) ^vithin Bering Sea during the past 

 three years from the 1956 experiments have provided first 

 quantitative estimates of v38 per cent and 40 per cent annually 

 for fishing mortality and emigration respectively. This fishing 

 mortality rate is higher than that found in any other section 

 of the coast, and indicates a high rate of utilization of Bering 

 Sea halibut by the present fishery in that region. The 40 per 

 cent annual rate of emigration accomits for the recovery of a 

 high proportion of Bering Sea tags in Areas 3 A and 2 and is 

 evidence of a close relationship between the stocks in Bering 

 Sea and those south and east of the Alaska Peninsula." 



The first two points could mean a very close relationship between 

 the eastern Bering Sea halibut stocks and the halibtU stocks in the 

 Gulf of Alaska and in Area 2. Of course, the extent of this relation- 

 ship has not been developed sufficiently to provide incontrovertible 

 evidence that these two stocks are actually dependent upon each 

 other. 



