Figure 7. -- Yellowfin c a t c h rates by 10-day 

 periods from 0° to 20°S. and 165°W. to 180° 

 by vessels based at Pago Pago, American 

 Samoa. /Data from Van Campen 1954. / 



rates is good evidence of a change in the abun- 

 dance or distribution of the yellowfin. The pos- 

 sibility that this change is related to a change 

 in the environment will be considered later. 



Discussion of individual cruises: The results 

 of concentrated fishing around Christmas Island 

 by the North American and Alrita during Jan- 

 uary to March and March to May have already 

 been discussed by Iversen and Murphy ( 1954). 

 In the former period, yellowfin catches averaged 

 5.6 but ranged from to 17.8 per 100 hooks for 

 individual stations; in the latter period, they 

 averaged 4.4 but ranged from 0.4 to 12.2 per 

 100 hooks. As shown by the summary of catch 

 rates according to sectors (figs . 8 and 9) no one 

 area seems to be significantly superior to the 

 rest. We may conclude therefore that during 

 this period the yellowfin were distributed in a 

 somewhat random fashion. Only a few catches 

 were made elsewhere in the Line Islands. 



On John R. Manning cruise 20 (fig. 10), in 

 May-June 1954, the best catch rates of 9. 3 and 

 9.4 yellowfin per 100 hooks were made near 

 Fanning and the poorest, to 0.2 yellowfin per 

 100 hooks, near Palmyra. 



On Oceanic cruise 1 (fig. 11), the fishing 

 was generally poor, with an average catch rate 

 of 0.9 for Christmas Island and an average of 

 1 . 5 for the seven stations in the vicinity of 

 Fanning Island. The Bro thers cruise 2 (fig. 12) 

 occupied only four stations each at Fanning and 

 Christmas Islands, with very low catch rates for 

 both islands. The rate at Fanning averaged 0. 9 

 and that at Christmis 1 . yellowfin per 100 hooks . 

 On Oceanic cruise 2 (fig. 13), only a single 



Figure 8.--Jangaard longline fishing ( Alrita and 

 North A merican catches combined), cruise 1, 

 January -March. 



Figure 9. --Jangaard longline fishing ( Alrita and 

 North American catches combined), cruise 2, 

 March-May. 



station was occupied near Fanning; eight fishing 

 days were spent in the vicinity of Christmas 

 Island and show a high of 3.4 and a low of 0.2 

 yellowfin per 100 hooks. 



On Commonwealth cruise 1 (fig. 14), fishing 

 centered in the vicinity of Christmas Island. A 

 high catch rate of 3. 3 and a low of yellowfin per 

 100 hooks were obtained. The Sea Haw k also 

 fished in the vicinity of Christmas Island with 

 poor results (fig. 15). Her best catch rate of 

 3. Oyellowfin per lOOhooks was made in the lee 



