contributed usually to high average catches 

 were off Kahului, off Kahuku Point, and in off- 

 shore west Oahu (fig. 5). Other regions of high 

 apparent abundance were off Kawaihae and in 

 the offshore region south of Oahu, where, inci- 

 dentally, the apparent abundance usually showed 

 the largest increase between the second and 

 third quarters. Another region which showed a 

 large average increase in apparent abundance 

 between these quarters was the offshore region 

 west of Oahu. In all the remaining regions ex- 

 amined in the third quarter, the Y/f averaged 

 between 2 and 3 metric tons. 



The apparent abundance of skipjack tuna was 

 usually higher in the fourth quarter than in the 

 first quarter but considerably lower than in the 

 second and third quarters. Figure 6 shows that 

 the distribution of apparent abundance was sim- 

 ilar to that shown for the first quarter, with 

 two exceptions (fig. 3). In the region off Hilo 

 Y/f averaged less than 1 metric ton in the first 

 quarter, whereas it averaged between 1 and 2 

 metric tons in the fourth quarter. The region 

 off Kawaihae also had higher apparent abun- 

 dance in the fourth than in the first quarter. 

 The regions off Kawaihae and offshore west 

 Oahu had the highest apparent abundance, av- 

 eraging 2.40 and 2.28 metric tons, respectively, 

 in this quarter. Although the decline in appar- 

 ent abundance in the fourth quarter was evi- 

 dent in all regions, two regions showed sharper 

 declines than the others. The Y/f decreased 

 from 3.57 to 1.69 metric tons in the offshore 

 region south of Oahu, and from 3.67 to 1.82 

 metric tons off Kahului. 



ACKNOWLEDGMENTS 



Tamotsu Shimizu, statistical clerk of the 

 Hawaii Division of Fish and Game, and Robert 

 M. Oka, leading fisherman aboard the R/V 

 Charles H. Gilbert , gave special help. Francis 

 M. Fukuhara, BCF Biological Laboratory, 

 Seattle, Wash.; Richard C. Hennemuth, BCF 

 Biological Laboratory, Woods Hole, Mass.; and 

 James Joseph, Inter-American Tropical Tuna 

 Commission, La JoUa, Calif., read the manu- 

 script. 



LITERATURE CITED 



SHIPPEN, HERBERT H. 

 1961. Distribution and abundance of skipjack 

 in the Hawaiian fishery, 1952-53. U.S. 

 Fish Wildl. Serv., Fish. Bull. 61: 281-300. 

 UCHIDA, RICHARD N. 



1967. Catch and estimates of fishing effort 

 and apparent abundance in the fishery 

 for skipjack tuna ( Katsuwonus pelamis ) 

 in Hawaiian waters, 1952-62. U.S. Fish 

 Wildl. Serv., Flsh.Bull. 66: 181-194. 

 YAMASHITA, DANIEL T. 



1958. Analysis of catch statistics of the Ha- 

 waiian skipjack fishery. U.S. Fish 

 Wildl. Serv., Fish.BuU. 58: 253-278. 



MS #1925 



