thus at liberty for 2 99 days. At release it 

 measured 92 cm. (about 33 1b.); unfortunately 

 onrecovery it was cut up without being measured 

 or weighed. The only estimate of size is that it 

 was "about 3 feet long. " 



Considering t h e fact that over 1,000 

 yellowfin were tagged in 1955-56 and that, aside 

 from the fishing of local residents, there has 

 been a fair amount of fishing effort expended in 

 the area by both POFI vessels and Japanese 

 longliners, it is perhaps noteworthy that more 

 tagged fish have not been recovered. This is 

 particularly true for the small fish tagged close 

 to the islands and presumed to be "local resi- 

 dents." The small number of recoveries could 

 indicate that most of the small yellowfin are not 

 year-round residents of the islands, but rather 

 that they move about in the equatorial Pacific. 



SUMMARY 



1. This report reviews the general results of 

 iiine combination longUning and trolling 

 cruises to the Line Islands between January 

 1955 and February 1956. 



2. There is evidence to support previous findings 

 that variation of longline catch rates among 

 vessels fishing simultaneously in the same 

 area is small. 



6. Higher troll catch rates of yellowfin were 

 obtained more frequently at Palmyra and 

 Kingman Reef to the north {6''N. latitude) 

 than at Christmas Island (2°N. latitude) to 

 the south. 



7. Consistent with past experience the catch 

 rates of longline yellowfin were higher close 

 to islands than in the open ocean. 



8. The longline catches in the open ocean were 

 consistently low as compared with previous 

 years, with the highest catch rates during 

 September. 



9. The insular longline catches demonstrated 

 considerable variability that did not seem 

 ascribable to seasonal or areal differences 

 in fishing. 



10. The Japanese longlining results in the equa- 

 torial region during 1955 also showed low 

 catch rates. 



11. A tagging program was carried out in con- 

 junction with abundance studies during which 

 1,056 yellowfin, 21 skipjack, 1 little tunny, 

 and 2 bigeye were tagged with plastic tube 

 tags. As of September 1956, two tagged 

 yellowfin have been recovered, both from 

 the same area in which they were released. 



3. The average depth reached by the deepest 

 longline hooks varied about 40 fm. during 

 these cruises. Near the Equator in the open 

 ocean the deepest hooks usually did not fish 

 as deep as they did at about 6°N. latitude or 

 within 10 miles of the various islands. 



4. The composition of the longline yellowfin 

 catches did not differ greatly from past 

 catches from the area; the ratio of males to 

 females for all cruises averaged 2.26:1.00 

 and both oceanic and insular yellowfin size 

 distributions had principal modes at the 140- 

 149 cm. class interval, but the insular catches 

 contained relatively nnore small fish. 



5. The trolling catches of yellowfin in the Line 

 Islands indicated that (1) the fish, with a 

 mode at 70-79 cm, , were generally smaller 

 thanthose taken on longline, (2) the overall 

 abundance was too low to recommend com- 

 mercial exploitation by this method, (3) 

 there was a seasonal trend in catch rates 

 with the highest catch rates obtained in 

 March-April and the lowest catch rates 

 during May-September. 



LITERATURE CITED 



BATES, D. H. , JR. 



1950. Tuna trolling in the L-ine Islands in 

 the late spring of 1950. U. S. Fish 

 and Wildlife Service, Fishery 

 Leaflet 351: 1-32. 



BLUNT, C. E. , JR. 



1954. Two mid-Pacific recoveries of 



California-tagged albacore. Calif. 

 Fish and Game 40(3): 339. 



CROMWELL, T. , R. B. MONTGOMERY, and 

 E. D. STROUP 



1954. Equatorial undercurrent in Pacific 

 Ocean revealed by new methods. 

 Science 119(3097): 648-649. 



GANSSLE. D. and H. B. CLEMENS 



1953. California-tagged albacore recovered 

 off Japan. Calif. Fish and Ganne 

 39(4): 443. 



12 



