Table 2. --Deviation of catch rates in certain unit areas west of 

 150 E. in December (cont'd) 



b. Area of 33°N. -35°N. , 143°E. -145°E. 



Note: Figures in ( ) are times of catch. 



As can be seen from table 2, the coefficients of variation for the 

 catch rates had high values, particularly in 19 50, when the majority were 

 over 100 percent. This shows that the catch rates, even within a single 

 unit area, can vary greatly from one day's operation to the next, and that 

 they can, in some cases, be widely different from the catch rates shown 

 in the average year's fishing condition charts. 



The most notable thing about tables 2a and b is that the average 

 catch rate is almost always somewhat higher than the most frequent catch 

 rate within an area, euid this is also true of the South Sea yellowf in grounds. 



In table 3 this whole area is divided into sections of 1 of latitude, 

 o 

 in 10 of longitude, and the coefficients of variation of the catch rates are 



shown for each section. In the table a tendency cam be seen for the values 



of this coefficient to be smaller in the south and larger in the north, with 



the highest values in the intermediate area. This shows that in the southern 



part of the area the fishing conditions are compairatively stabilized, with 



little deviation from the average catch rate, whereas in the northern part 



fishing conditons are unstable, with large catches in some cases and no 



catch at all in others. The very same sort of situation is found in the area 



north of 35 N. , between 150 E. auid 155 E. , which is considered to be a 



prolongation of the fishing grounds west of 150 E. 



This table shows that throughout this sea area as a whole the average 

 coefficient of variation is 70 percent, from which it can be seen that the 

 fluctuations in albacore fishing conditions in this region are rather large. 

 As will be noted later, the variations in the fishing conditions in the waters 

 east of 160 E. are not as great as they are in this area and, from this point 

 of view, it can probably be thought that the two fishing grounds differ in 

 character. 



35 



