SKIPJACK IN HAWAII FISHERY 



285 



Figure 4. — Hawaii skipjack fishery fishing zones and regions and the extent of fishing in 1952 and 1953. 



making the catch. The number of fishermen is 

 used as a factor in the computation of fisliing effort 

 because it seems reasonable that in pole-and-line 

 fishing the efficiency of a vessel is more or less di- 

 rectly related to the number of men hooking fish. 

 No adjustments were made for ditl'erences in trip 

 time or for deviations from the official number of 

 fishermen. Inasmuch as a fish-catch report is re- 

 quired only if fish are caught, the imit of effort 

 employed in this study is the productive fisher- 

 man-trip. Thus, if a vessel with a regi.stered crew 

 of 10 men reported a catch of 20,000 pounds, the 

 effort is considered to be 10 units and the catch 

 per unit of efi'ort is 2,000 pounds. If two or more 

 catch reports were combined, the sum of the 

 catches was divided by the sum of the efi'ort to 

 oht ai n t he catch per unit of effort. 



To gain some knowledge of the reliability of the 

 productive trip as a factor in tiie unit of efi'ort, 

 the logbooks of two Honolulu-based skipjack fish- 

 ing sampans were analyzed to determine the ratio 

 of productive trips to the actual number of days 

 spent fishing; i.e., the time spent in scouting for 

 and catching skipjack. The results of this analysis 

 appear in table 2. Boat .1 is typical of the fleet 

 as a whole in that it makes freciuent trips of sel- 

 dom more than a single day. Boat B. on the other 

 hand, is probably the most atypical in the fleet 

 since it ventures far afield and may remain at sea 

 for as many as 4 days, especially when skipjack 

 are relatively scarce. The ditl'erences between the 

 two boats are apparent in the number of trips per 

 biweekly period (col. 7) and the number of trips 

 per day's fishing (col. 10). 



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