N. by April. In figure 15 we can see that the 

 center of effort is located at long. 160° E., lat. 

 26° N. in November and moves south and west 

 to long. 155° E., lat. 19° N. in April. The cen- 

 ter of effort is to the west of CPUE in Novem- 

 ber, but by April the center of effort is to the 

 east of the CPUE. Latitudinally, however, the 

 relative positions of CPUE and effort are sta- 

 ble; the centroid of effort is always several 

 degrees to the south of CPUE. Thus, the dis- 

 tribution of effort is not centered on apparent 

 abundance. 



The striking feature of figure 14 is that there 

 is only a slight variation (for fishery data) of 

 the observed points around the general mean. 

 This consistency is especially striking when 

 one considers that the moment could be dis- 

 tributed over a much larger area of ocean. The 

 low variability in the distribution of the CPUE 

 data suggests that highly accurate predictions 

 could be made for the location of apparent 

 abundance of albacore during the peak months 

 by the use of only the data in figure 14. 



55 



Sfc 



Y=!52.I6+0 4I73X 



1 1 r 1 1 ' i i r 



Y = 26 70-0 5I56X 



Y=I3 30 + 7468X 



1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 I960 1961 

 Figure 11. --Trends in February effort spatial statistics. 



17 



