43 



Although assessment theory had held that increases in effort would 

 not greatly increase landings, the abundant year-class of 1963 as well as 

 the use of small mesh nets by the Soviets had a critical effect on the 

 stock: 



A Summary of the Trends from 1960 to 1965 



1960 1961 1962 1963 1964 1965 



(a) Percent of maximum equilibrium yield level 



A glance at landings in relation to effort (pounds per day fished) for 

 the period 1940 - 1969 shows that, while the basis of the 1962 prediction 

 might have been true over the long term, in fact the technological capacity 

 of fleets distorted assessment expectations by demonstrating a harvesting 

 capacity quite capable of continuing a high yield/effort ratio well into 

 the depletion area of the traditional yield/effort curve : ^ ' 



