FISHERY BULLETIN: VOL. 72, NO. 4 



There are two large fisheries in the Pacific, on 

 the Peruvian anchoveta and on the Alaska pol- 

 lack. Recently the anchoveta recruitment failed, 

 possibly due to fishing and possibly due to El Nino 

 and perhaps due to both; because there is only 

 about one decade of observations, the cause of fail- 

 ure will probably remain unknown, although it 

 must always be admitted that the fishing mortal- 

 ity is high. In the Bering Sea there is a rising 

 fishery on the Alaska pollack that also had been in 

 existence for less than a decade. The potential 

 managers of this fishery might like to have avail- 

 able now a yield curve before the data are avail- 

 able to describe the stock and recruitment curve. 

 The source of scientific failure here is the inability 

 to generate an analytic stock and recruitment 

 model. 



SCIENCE AND MANAGEMENT 

 IN THE COMMISSIONS 



When a fish stock fails the question arises 

 whether the failure should be attributed to the 

 Commission charged with its management or to 

 the scientists. There is a distinction between the 

 North Atlantic Commissions and those in the 

 North Pacific. In the North Atlantic the two insti- 

 tutions (International Commission for the North- 

 west Atlantic Fisheries and Northeast Atlantic 

 Fisheries Commission) are responsible for all 

 stocks exploited in the area, whereas in the east- 

 ern North Pacific only those of interest to North 

 American fishermen are conserved. Consequently 

 the Commissions in the North Atlantic cannot 

 disclaim responsibility for any failures that occur 

 in their area, whereas the North Pacific Commis- 

 sions may be able to do so. 



In the North Atlantic, decline of the main de- 

 mersal stocks has with one exception been pre- 

 vented. The best conservation has not yet been 

 achieved, but with the use of catch quotas and 

 international enforcement there is considerable 

 hope that conservation will ultimately be very 

 effective. The scientific basis for this was the ini- 

 tial use of the yield per recruit model and in recent 

 years the successful application of first, cohort 

 analysis (Gulland, 1967), and secondly, the 

 Clayden model (Clayden, 1972). On the other 

 hand, the collapse of herring stocks in the north- 

 east Atlantic was due entirely to the scientific 

 failure to understand the nature of the stock and 

 recruitment problem. Both success and failure in 

 the Commissions can be linked to success or fail- 

 ure in the science. 



In the North Pacific there are large areas of 

 unregulated fishery, which the North Pacific 

 Commission has not taken under its aegis. The 

 cause of the increase in the maximum sustainable 

 yield of the yellowfin tuna in the area of the 

 Inter-American Tropical Tuna Commission is un- 

 known, although a number of possible reasons 

 have been cited. Halibut are caught by trawl by 

 nations outside the control of the International 

 Pacific Halibut Commission. The question of the 

 offshore exploitation of the Pacific salmon stocks 

 remains unresolved because the boundary be- 

 tween the North American and Asian stocks is not 

 precise and the degree of mixture in the exploited 

 area has not been established. 



It remains true, of course, that the stock density 

 of the halibut recovered from 1930 to 1960 by the 

 action of the Halibut Commission, that the 

 offshore exploitation of the North American salm- 

 on was prevented by the abstention principle, 

 and that the yellowfin tuna stock is well exploited. 

 Some of the failures in the North Pacific, like those 

 in the North Atlantic, are rooted in scientific 

 deficiencies (apart from the North Pacific failure 

 to consider stocks that are outside the aegis of the 

 Commissions). 



The International Whaling Commission failed 

 to conserve the stock of blue whales. The problem 

 was solved in principle for the fin whale by Ruud 

 (International Whaling Commission, 1956) but 

 the solution was rejected by Schlijper (Interna- 

 tional Whaling Commission, 1957) who said that 

 the age determination was faulty. The Committee 

 of Four evaded this by expressing the results in 

 the form of a Schaefer curve (International Whal- 

 ing Commission, 1964); Schlijper never saw that 

 age determination was used in the estimation of 

 (recruitment less mortality) which played a con- 

 siderable part in the solution. Part of the failure to 

 conserve the stock was the delay in reaching an 

 agreed scientific solution. 



In contrast to the Whaling Commission, the 

 North Pacific Fur Seal Commission has been well 

 served by its scientists. A form of stock and re- 

 cruitment relation has been established and the 

 surplus stock is taken each year at somewhere 

 near the best point for exploitation, and some 

 progress has been made towards establishing the 

 nature of the density-dependent control in the 

 population. The Fur Seal Commission is the oldest 

 of the international commissions and its records 

 go back a long way, into the early 19th century. 



From this very brief account of the role of 



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