Size of fish . --The size of skipjack tuna caught 

 in Hawaiian waters is an important factor in 

 the success of a fishing season. The influx of 

 large numbers of "season" fish in the fishery 

 marks the height of the fishing season, usually 

 from May to September, and these fish consti- 

 tute a major portion of the landings annually. 



There appear to be four size groups in the 

 catch: < 4 kg. = small; 4-7 kg. = medium; 7-10 

 kg. = season; and > 10 kg. = extra large. Be- 

 cause large fish bring better prices, the Ha- 

 waiian tuna fishermen usually pass up schools 

 of small and sometimes medium fish for large 

 "season" fish. In table 12 and figure 10, 

 which show the size of fish caught by the seven 

 vessels in June-August 1967, we noted that 

 "season" fish were rather scarce in the catch, 

 constituting only about 5 percent of the schools 

 fished. Much more frequent were schools of 

 extra-large fish (63 percent), which are usually 



not as frequently encountered as schools of 

 "season" fish, and schools of small fish (25 

 percent), with schools of medium fish only 

 slightly more frequent in the catch than schools 

 of "season" fish. We also plotted the averages 

 of catch per school, amount of bait used per 

 school, number of men hooking per school, and 

 fishing duration, by fish size, and found that 

 some tended to increase whereas one decreased 

 as fish size increased; only two of the correla- 

 tions, those for the number of fish caught per 

 school and for the number of men fishing per 

 school with size of fish, did not differ signifi- 

 cantly (table 8). The fact that the correlation 

 coefficient of the average number of men fish- 

 ing and fish size did not differ significantly led 

 us to our earlier conclusion that variation in 

 the number of men fishing did not contribute to 

 variation in average fish size. 







16 



0' 





15 



9. 





■ 



15 



NOF 



8° 



ITH 





15 



7° 





15 



6" 



w. 



15 



5° 

















2 

 2 







 1 



















N. 











.AUAI 1 



5 

 8 









5 

 7 



1 



2 









 3 















-22° 



NIIH/ 



2 



3 



r 



"4 



5 

 8 



10 

 12 



2 

 10 





 2 



13 

 18 



18 

 31 



2 

 3 







1 



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 1 









22»- 







1 

 1 



5 

 7 



8 

 9 



5 

 8 



14 



29 



57 

 95 



^ \^ 

 240AHU(5 



29a ^ \ 



24 

 36 



17 

 29 



5 

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-21" — 



WESl 





7 

 8 



10 

 17 



9 

 18 



19 

 41 



68 

 142 



80 

 149 



24 

 25 



7 

 9 















EAST 







1 



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 2 





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 2 



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 8 



23 

 42 



24 

 35 



33 

 43 



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 5 











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— 2I°- 















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 1 



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 6 



3 

 7 



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 9 





 1 



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 2 





< 















-20»— 









1 

 1 



1 

 1 



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 1 



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— 20»- 



















1 



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 1 













n M Tf M 1 1 





H9» 

















SOI 



JTH 

























16 







15 



9° 





15 







15 







15 







15 



19°- 



5° 



Figure 12. — Ratio of the number of schools successfully fished (upper figure) to the number of 

 schools sighted (lower figure), by 20-minute areas of longitude and latitude in Hawaiian waters, 

 June-August 1967. 



17 



