intensity were not correlated significantly over 

 the 11-year period (r -0.343; df = 9; 

 p = 0.32). The lack of correlation suggested 

 that changes in the size of the Y/f were not 

 influenced by changes in the amount of fishing, 

 but by other fishery-independent factors, such 

 as variation in availability and vulnerability; 

 the strength of year classes also may be im- 

 portant (Rothschild, 1965). The eflfective fish- 

 ing intensity tended to decline over the years 

 under study, largely because of a decrease in 

 the number of vessels in the fleet. 



ACKNOWLEDGMENTS 



Two Hawaii State Government agencies as- 

 sisted in the preparation of this paper: The 

 Division of Fish and Game of the Department 

 of Land and Natural Resources made available 

 all its catch statistics and interview records 

 and the Division of Archives of the Depart- 

 ment of Accounting and General Services per- 

 mitted the use of its facilities. The Computing 

 Center of the University of Hawaii provided 

 technical assistance. Robert R. Parker reviewed 

 the manuscript. 



LITERATURE CITED 



Ahlstrom, E. H. 



1960. Fluctuations and fishing. In H. Rosa, Jr., 

 and Garth Murphy (editors), Proc. World Sci. 

 Meet. Biol. Sardines Related Species 3: 1353~ 

 1371. Food Agr. Organ. United Nat., Rome, Ital. 



GULLAND, J. A. 



1955. Estimation of growth and mortality in com- 

 mercial fish populations. Fish. Invest., London, 

 Min. Agr. Fish. Food, Ser. II, 18(9), 46 pp. 



1956. On the fishing eff'ort in English demersal 

 fisheries. Fish. Invest, London, Min. Agr. Pish. 

 Food, Ser. II, 20 (5), 41 pp. 



June, Fred C. 



1951. Preliminary fisheries survey of the Ha- 



waiian-Line Islands area. Part III. The live-bait 

 skipjack fishery of the Hawaiian Islands. Com. 

 Fish. Rev. 13(2) : 1-18. 



Rothschild, Brian J. 



1965. Hypotheses on the origin of exploited skip- 

 jack tuna {Katsinvonus pclamis) in the eastern 

 and central Pacific Ocean. U.S. Fish Wildl. 

 Serv., Spec. Sci. Rep. Fish. 512, iii -f 20 pp. 



RoYCE, William R., and Tamio Otsu. 



1955. Observations of skipjack schools in Ha- 

 waiian waters, 1953. U.S. Fish Wildl. Serv., 

 Spec. Sci. Rep. Fish. 147, v + 31 pp. 



Schaefer, Milner B. 



1963. Statistics of catch and effort required for 

 scientific research on the tuna fisheries. In H. 

 Rosa, Jr. (editor), Proc. World Sci. Meet. Biol. 

 Tunas Related Species 6(3): 1077-1086. Food 

 Agr. Organ. United Nat., Rome, Ital. 



Seckel, Gunter R. 



1963. Climatic parameters and the Hawaiian 

 skipjack fishery. In H. Rosa, Jr. (editor), Proc. 

 World Sci. Meet. Biol. Tunas Related Species 

 6(2): 1201-1208. Food Agr. Organ. United 

 Nat., Rome, Ital. 



Seckel, Gunter R., and Kenneth D. Waldron. 



1960. Oceanography and the Hawaiian skipjack 

 fishery. Pac. Fisherman 58(3): 11-13. 



Shimada, Bell M., and Milner B. Schaeffer. 



1956. A study of changes in fishing eff'ort, 

 abundance, and yield for yellowfin and skipjack 

 tuna in the eastern tropical Pacific Ocean. Inter- 

 Amer. Trop. Tuna Comm., Bull. 1(7) : 351-469. 



Shippen, Herbert H. 



1961. Distribution and abundance of skipjack in 

 the Hawaiian fishery, 1952-53. U.S. Fish Wildl. 

 Serv., Fi.sh., Bull. 61: 281-300. 



Yamashita, Daniel T. 



1958. Analysis of catch statistics of the Hawaiian 

 skipjack fishery. U.S. Fish Wildl. Serv., Fish. 

 Bull. 58: 253-278. 



Yuen, Heeny S. H. 



1959. Variability of skipjack response to live bait. 

 U.S. Fish Wildl. Serv., Fish. Bull. 60: 147-160. 



194 



SKIPJACK IN HAWAIIAN WATERS 



