COMMERCIAL POSSIBILITIES 



The only large-scale commercial longlme fishing for tuna 

 is conducted by the Janenese, In 1 P50 and 1951 the Japanese fishing 

 industry sent nine tuna mothership longline fishing expeditions into the 

 equatorial area west of 180° « Details of these can be found in 

 papers by Shimada (l95l)j Ego and Otsu (1952), and Van Campen (1952 )o 

 That these expeditions met vath success is implied by their numbero 

 This, however, does not mean that a similar venture in the same area, 

 if undertaken by American fishermen, would be financially successful, 

 because there are differences in basic costs. For instance, a 

 Japanese fisherman's income is equivalent to $50-75 for a fishing 

 trip lasting a month (Ego and Otsu 1952). 



The survey fishing reported herein has revealed a greater 

 concentration of tuna in the equatorial waters of the central 

 Pacific area than has been found in the far western Pacific by the 

 Japaneseo This is indicated by a ca^oh rate of 12„3 yellowfin tuna 

 p-iT hundred hooks in the rioh area just north of the Equator between 

 150* and 157° Wo longitude!/ as compared to an average of approxi- 

 mately three tuna of all species per hundred hooks for the nine 

 Japanese expeditions (Ego and Otsu 1952) in the western Pacific„ As 

 yet, definite conclusions in relation to an American fishery cannot 

 be drawn, since the 12o3 yellowfin per hundred hooks is based on one 

 cruise (Smith Cruise 11) covering 2 months, August and September 1951, 

 although some corroboration is found in the results of Smith Cruise 7o 

 By contrast the Japanese expeditions cover a number of months through 

 2 years. 



A detailed study of the catch rates, fishing time, seasonal 

 variation, and other factors concerning availability of tuna in the 

 central Pacific must be completed before definitive comparisons 

 between the two areas can be made. However, there is little doubt 

 that commercial fishing by an American vessel would be feasible if 

 catches were as high as those experienced by the Smith on Cruise llo 

 By way of comparison, the first six Japanese expeditions averaged 

 about three tuna totaling 250 pounds per hundred hooks o Our survey 

 fishing in the rich latitudes in the vicinity of 150* W, longituds 

 brought in 12,3 yello\vfin per hundred hooksj, equivalent to 1,500 

 poundso If a purse seine-type vessel with a crew of 12 men were 

 able to fish 900 hooks per day, and if it maintained an average rate 

 of capture of 12,3 yelloivfin, 13,500 pounds of yellowfin per day 

 could be expected. This probably is enough to support an American 

 fishing boat, even when considering deductions for shark damage and 

 cannery rejection. 



zZ 



This figure is based on stations 10-23 of Smith Cruise llj, 

 excepting station 14. The selection was not entirely arbitrary 

 as the poor catch stations to the north and south were fished 

 only in order to delimit the rich zonso 



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