HANAN: BLUEFIN TUNA FISHERY 



Table 4. — Total occurrences of recorded bluefin tuna catch 

 per latitude and month during 1957-69 and 1974. Totals are 

 for the areas between a given parallel and the next higher par- 

 allel. 



MONTH 

 FMAMJ JASOND 



LU 

 Q 



<1 



1-3 



>3 



Figure 6.— Mean monthly effort for bluefin tuna (Jil.) for the 



13 

 period 1957-69 in boat-days per latitude. Totals are for areas 

 between a given parallel and the next higher parallel. 



part of the bluefin range (Figs. 8-10), and is at- 

 tributed to differences in searching and fishing 

 methods between the wetfish and the high-seas 

 fleets. 

 Because effort data are not available for the 



Y = 10.5-0.1 14X 



1955 1960 1965 1970 1975 1980 

 YEAR 



Figure 7.— Annual catch per unit effort (metric tons/boat- 

 day) of bluefin tuna plotted by year ( 1954-78) with a regression 

 line fitted to the curve. 



MONTH 

 J FMAMJ JASOND 



0*5 



6-75 



>75 



Figure 8.— Mean monthly catch per unit effort of bluefin tuna 



m 



< i 'per latitude (metric tons/boat-day) for the period 1957-69. 



13 

 Totals are for areas between a given parallel and the next high- 

 er parallel. 



1979-81 period, the rapid decline in total catches 

 during those years cannot be explained by direct 



111 



