Effort . --Refer ring to table 3, the maximum 

 longitudinal first moment (eastwardmost exten- 

 sion) of effort occurred in July through October. 

 The minimum longitudinal first moment (west- 

 wardmost extension) came in March through 

 June. The maximum latitudinal moment (north- 

 ernmost extension) was most often in Septem- 

 ber, October, and November although this max- 

 imum did occur in March and April. All months 

 except August, September, and December 

 showed a maximum longitudinal standard devi- 

 ation and the minimum longitudinal standard 

 deviation occurred in January through April 

 and also in July. The latitudinal standard de- 

 viation of effort attained maximum values 



mostly in the third quarter — July, August, and 

 Septeniber--whereas the values were minimum 

 in the first quarter, in June and July, and in 

 October. The correlation coefficient was at a 

 maximum in November, December, and Janu- 

 ary; it was at a minimum in March through July 

 and also in September. 



From figure 8 we can see the relation be- 

 tween the spatial statistics for effort and the 

 peak fishing periods. The longitudinal moment 

 is generally at a minimum value during the 

 peak fishing period. The latitudinal moment 

 tends to be near its maximum value at the be- 

 ginning of the peak period and tends to decline 

 through the peak period. Both the latitudinal 



° 8 



o 



10 



5 







-5 



-IC 



160' 



w, 



170' 



170° 



150" 



E 



140' 

 40' 



N 

 30' 





Figure 8. --Spatial statistics for effort 1949-61 on the North Pacific albacore 

 longline grounds. The heavy line represents the peak fishing period from 

 December to March . --Cont i nued . 



II 



