FISHERY BULLETIN: VOL. 81, NO. 1 



Table 5. — Yearly catch (metric tons) of bluefin tuna and effort (in parentheses) 

 by vessel size class for 1957-69 and 1974, from logbook data. Hold capacity in 

 short tons: 0-50 = Class 1; 51-100 = Class 2; 101-200 = Class 3; 201-300 = Class 4; 

 301-400 = Class 5; over 400 = Class 6. 



14 



12 



10 



3 



a. 

 o 



' NORTH 



1957 1960 1963 1966 1969 1972 1975 

 YEAR 



Figure 9. —Annual catch per unit effort of bluefin tuna (metric 

 tons/ boat-day) for 1957-69 and 1974 north and south of lat. 

 32 °N. 



CPUE evidence. However, if it is assumed that 

 effort remained at about the same levels, CPUE 



6.0 

 4.5 



2 3.0 - 



1.5 - 



0.0 L 



z> 

 a. 

 O 



20° 



_L 



24° 



28° 32° 

 LATITUDE 



36° 



40° 



Figure 10.— Bluefin tuna catch per unit effort (metric tons/ 

 boat-day) by latitude for 1957-69 and 1974. Latitude area is 

 that lying between a given latitude and the next higher lati- 

 tude. 



would have declined by an even greater rate than 

 that predicted by the trend in Figure 7. This in- 

 dicates that bluefin abundance in the eastern 

 North Pacific has declined severely. 



112 



