stayed with the vessel longer. Excluding fish- 

 ing duration of longer than 60 minutes, we cal- 

 culated correlation coefficients for the data in 

 table 10 and found that they differed signifi- 

 cantly from p = 0. Figure 9 shows that the av- 

 erage number and weight of fish caught per 

 school were larger with more time spent fish- 

 ing the schools. It also turned out that the ves- 

 sels usually had more men fishing those schools 

 that bit longer, possibly because the captains 

 and engineers spent more time fishing and 

 were, therefore, included in the effort. Our 

 data showed that the vessels usually caught 

 larger fish from schools that bit longer. 



Table 11. — Number and percentage of 585 schools 

 fished by seven Hawaiian skipjack tuna fishing 

 vessels, tabulated by reasons cited for aban- 

 doning successfully fished schools , June-August 

 1967 



Reason for abandoning schools 



Schools 



Biting slowed 



Biting stopped 



School sounded 



Other reasons (small fish, 



presence of predators, no 



bait left) 



Number Percent 



24A 

 232 

 A6 

 63 



A1.7 

 39.6 

 7.9 

 10.8 



400 



200 





 100 



' 1 1 1 1 [ r- 



NUMBER CAUGHT PER SCHOOL 



■y 



WEIGHT CAUGHT PER SCHOOL 



I 1 1 1 1 1 1 1 



ANflOUNT OF BAIT USED PER SCHOOL 



qI I I I I L _J I L 



I I r 



"T 1 1 1 \ r 



NUMBER OF MEN FISHING 



I I I I I L 



1 I I I I r 



AVERAGE SIZE 



J m 



NUMBER OF SCHOOLS 



I 6 II 16 21 26 31 36 4! 46 51 56 > 60 

 I I I I I I I I I I I I 

 5 10 15 20 25 30 35 40 45 50 55 60 



FISHING DURATION (MINUTES) 



Figure 9. — Relation between fishing duration and 

 average values of catch per school, amount of 

 bait used per school, number of men fishing per 

 school, and size of fish per school, June-August 

 1967. 



100 



50 



NUMBER CAUGHT PER SCHOOL 



1 i 1 \ 1 1 r- 



WEIGHT CAUGHT PER SCHOOL 



T 1 1 1 1 1 1 [— 



AMOUNT OF BAIT USED PER SCHOOL 



NUMBER OF MEN FISHING PER SCHOOL 



J I I \ I \ I \ , 



1 1 1 \ 1 1 1 J- 



FISHING DURATION PER SCHOOL 



Oi_J 1 L 



300 1 



J \ I I I L 



NUMBER OF SCHOOLS 



\}f}>l una 



1 



II 2 1 3 1 4 I 5 1 6 1 7 1 e I 9 1 10. 1 Ml 12 I 13.1 

 2 30 4.0 50 60 7 80 90 100 110 120 13 > 

 SIZE OF FISH (KG.) 



Figure 10. — Relation between size of fish and 

 average values of catch per school, amount of 

 bait used per school, number of men fishing per 

 school, and fishing duration per school, June- 

 August 1967. 



15 



