Table 6a. --Surface temperature and catch rate, December, 

 30°N. -35°N. , 140°E.-150°E. 



Note: The "mean" is the average catch rate. 



Table 6b. --Surface temperature and catch rate, December, 

 35°N. -40°N. , 140°E.-150°E. 



1.09°C. 



North of 35 N. 



made and the standard deviation are 19.6 



o o — 



these figures are 17.8 + 1.75 C. Thus the water temperature at 



which the highest catch rates are recorded is different in the two areas, 



amd it is thought to be probably unreasonable to attempt to determine a 



so-called favorable water temperature which can be applied to the whole 



fishing ground. 



Table 7. --Standard deviation 

 ((t) amd coefficient of varia- 

 tion (o-/M) of catch rate with 

 temperature 



Table 7 shows the difference in 



the catch rates at a given water tempera- 



o 

 ture for the areas north and south of 35 N. ; 



the coefficients of variation are greater 

 than 60 percent. It is thought that such 

 a large deviation indicates that there are 

 other important elements in the formation 

 of the fishing grounds besides water tenn- 

 perature. At any rate, the surface water 

 temperature, although it may be an essen- 

 tial element in the development of a 



41 



