gitudinal moments occurs during the beginning 

 of the second quarter of the year. The latitu- 

 dinal moments usually have their maximum 

 values in September or October and their mini- 

 mum values in the second or third quarter. 

 The maximum longitudinal standard deviations 

 occur mostly in the second quarter whereas 

 values tend to be minimal in March or April or 

 several months later, in the third or fourth 

 quarter of the year. The latitudinal standard 

 deviations exhibit maximum values most fre- 

 quently in the third quarter, and their minimal 

 values most typically are in the first quarter. 

 The correlation coefficient has its maximal 

 values in the latter half of the year; most min- 



imal values occur during the second quarter. 



Returning to figures 9 and 10, we can see the 

 relation of the spatial statistics for catch and 

 CPUE to the peak fishing period. The pattern 

 they exhibit is remarkably consistent among the 

 13 years for which we have data. The longitu- 

 dinal moment, for example, declines throughout 

 the peak period and reaches its minimum value 

 at or near the end of that period. The peak 

 period appears to be superimposed on the latter 

 portion of a net westward movement of the lon- 

 gitudinal moments. Similarly the latitudinal 

 moment for both catch and CPUE exhibit a net 

 decline throughout the peak period; the rate of 

 decline of the latitudinal moments, however. 



o 



< 

 > 



150' 

 E 

 140' 



t 10 



Figure 9-""Spatial statistics for catch ig^g-Sl on the North Pacific albacore 

 longline grounds. The heavy line represents the peal< fishing period from 

 December to March . --Cont i nued. 



13 



