are not surprising. Both may be partially excluded from the catches 

 by gear selection in respect to fishing depth and hook size. In 

 addition the albacore appears to be a temperate zone species and 

 therefore would not be expected to equal the yellowfin abundance in 

 the equatorial zone. 



Many important tuna fisheries, such as those of the Pacific 

 coast of the Americas, are located relatively close to land. It is 

 quite clear from figure 10 that the stocks of tuna under discussion 

 are not related to any land masses. This is particularly evident 

 from the lateral series extending along 2° N, latitude from Christmas 

 Island to 150° VJ', longitude., On the other hand there is some evidence 

 that the immediate vicinity of the small islands of the central 

 Pacific presents a generally favorable habitat for tunas independent 

 of the character of the general water masses surrounding them. 



The most graphic evidence available for concentrations of 

 tuna around the small oceanic islands is afforded by POFI trolling 

 recordSo Bates (1950) records an average catch of four tuna per 

 hour in the Line Islands area. The good fishing was limited to an 

 area extending up to 2 miles from the reefs. Catches by POFI vessels 

 beyond these limits are in the magnitude of one or two fish per day 

 at best. It should be pointed out, however, that the latter are the 

 catches resulting from trolling which is done during passage between 

 stations, when the speed of the vessel is faster than that considered 

 optimum for catching tuna. 



There is less material available on the distribution with 

 respect to land of the deep-swimming tunas. Three stations during 

 Cruise 7 of the Smith (19, 20, and 26) were located very close to 

 small islands and their catches appear to be generally higher than 

 their oceanic counterpartSo Fishing near Canton Island yielded good 

 longline catches (table 1, fig, ll), with the stations closer to the 

 island usually yielding the higher catcheso Station 17 of Smith 

 Cruise 11, located very close to Christmas Island, produced a catch 

 of about the same magnitude as the oceanic stations, but the size of 

 the yellowfin tuna was considerably smaller (fig, 15, table 11 ) 

 indicating that perhaps the island catch was drawn from a different 

 group of tuna. 



In summary, the evidence points to a rather consistent 

 relatively high abundance of yellowfin tuna in the immediate vicinity 

 of these small oceanic islands, with the level of the oceanic stocks 

 of deep-swimming tunas determined by factors independent of the 

 islands. Whether the island stocks represent complete discrete 

 populations or are merely aggregations of transient individuals is 

 not known. 



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