length again decreased in February 1965, but by 

 tlie end of the year the albacore landed in Samoa 

 ■were even larger than in 1962-63. 



16. Several factors are responsible for changes 

 in mean lengths of albacore. One of the primary 

 causes is change of fishing grounds ; fishing is con- 

 fined during the early months of the year to more 

 northern waters, north of lat. 15° S., where the al- 

 bacore tend to be small. As some of the fishing 

 shifts southward beginning about June or July, the 

 lengths of albacore gradually increase since the 

 largest fish occur near lat. 20°-25° S. Albacore are 

 smaller to the south of lat. 25° S. 



17. We found no longitudinal differences in av- 

 erage fish sizes. 



18. The general decrease in average lengths of 

 albacore taken in 1964 as compared to 1962-63, 

 may have been due in part to an abundant year 

 class of small albacore that entered the fishery 

 early in 1964. As this year class moved through 

 the fisherj-, average size increased slightly toward 

 the latter part of 1964. The data suggest that an- 

 other large year class of small albacore entered 

 the fishery early in 1965. 



19. Although albacore are generally smallest in 

 areas north of 15° S., sizes also vary seasonally 

 within the same areas. The fish are smallest during 

 February-May when coincidentally the vessels 

 tend to concentrate their fishing in this northern 

 area. 



20. Males average 1 to 6 cm. longer than females 

 each month ; therefore, any change in the sex ratio 

 affects the average size of fish in the catch. Indeed, 

 during the periods of reduced mean sizes in 1964 

 and 1965, the percentage of males decreased, per- 

 mitting the smaller females to have an unusually 

 depressing effect on the average size of the alba- 

 coi-e. The smaller catch (in weight) per unit of 

 effort could be attributed partly to the change in 

 sex ratio. 



ACKNOWLEDGMENTS 



The early stages of the sampling (September 

 1962-April 1963) were supervised by Thomas 

 Annastas, then Supervisor of Fisheries for the De- 

 partment of Agriculture, Government of Ameri- 

 can Samoa. Our sampling field station in Pago 

 Pago was established through the cooperation of 

 Governor H. Rex Lee, of the Government of 

 American Samoa, and the management of the Van 

 Camp Sea Food Company in Samoa. The contin- 



ued success of the field station in providing data 

 from the fishery is due to the cooperation of the 

 management and staff of the Van Camp Sea Food 

 Company-Samoa and the recently established 

 (1963) Star-Kist Samoa, Inc., who allow our per- 

 sonnel to sample the landings at their canneries. 

 The fishing vessel operators from Japan, the Re- 

 public of Korea, and the Republic of China pro- 

 vided us with detailed information on their fishing 

 operations. 



The fishery technicians from the BCF Labora- 

 tory in Honolulu who have served and continue to 

 serve at the field station have collected the data 

 used in this study. Andrew Scanlan of Samoa as- 

 sisted our personnel at the field station. 



The following have read the manuscript and 

 have offered suggestions: Marvin D. Grosslein, 

 Cornell University, Ithaca, New York; Robert 

 W. Hetzler, Star-Kist Food, Inc., Terminal Island, 

 California; and Henry A. Regier, University of 

 Toronto, Toronto, Canada. We also wish to thank 

 Gordon Broadhead, Van Camp Sea Food Com- 

 pany, who read an early version of the manuscript. 



LITERATURE CITED 



HoNMA, MisAO, and Tadao Kamimura. 



19.57. Studies on the albacore. V. The fishing condi- 

 tion and size of albacore taken in the South Pacific 

 Ocean. Rep. Nanljai Reg. Fish. Res. Lab. 6 : 84-90. 

 [In Japanese with English summary.] 



Japan Fisheries Agency. 



1965. Annual report of effort and catch statistics by 

 area on Japanese tuna long line fishery 1962. Res. 

 Div. Fish. Agency Japan, 183 pp. 



1966. Annual report of effort and catch statistics by 

 area on Japanese tuna long line fishery 1963. Res. 

 Div. Fish. Agency Japan, 322 pp. 



Koto. Tsutomu. 



1966. Studies on the albacore. XI. Distribution of 

 albacore in the tuna longline fishing grounds of 

 the South Pacific Ocean. Rep. Nankai Reg. Fish. 

 Res. Lab. 23: 43-53. [In Japanese with English 

 summary.] 

 Nankai Regional Fisheries Research Laboratory. 



1959. Average year's fishing condition of tuna long- 

 line fisheries. 1958 ed. (Text and atlas.) Federation 

 of Japan Tuna Fishermen's Cooperative Associa- 

 tions, Tokyo, text 414 pp. [In Japanese with Eng- 

 lish figure and table captions.] 

 Suzuki, Goro. 



1961. On tuna fishing at the Samoa base in 1956. 

 Tuna Fishing {Maguro gyogyo) 76: 13-18. [In Jap- 

 anese.] 

 Van Campen, Wilvan G. 



1954. Tuna fishing at American Samoa, January- 

 April 1954. Commer. Fish. Rev. 16(11) : 1-9. 



ALBACORE TAKEN IN LONGLINE FISHERY IN AMERICAN SAMOA 



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