to the North Equatorial Current (carried out in January 1953). The surface 

 water temperature rises to the south, and just in the area which corresponds 

 to this fishing ground the warm water is distributed to a considerable depth 

 and the thermocline is quite deep. (Since we have data from observations 

 only to 150 m. , the location of the thermocline is not very clear. ) Waters 

 of low temperatures form a pealc between this area and the area of the 

 North Equatorial Current (station 6), clearly showing its boundary and 

 indicating that conditions in this sea area are quite different from those 

 in the area of the North Equatorial Current. 



o o 



(2) Other Grounds in the Waters Between ION. and 25 N. Latitude 



It has already been remarked that there is always a scattering 

 of catches of large albacore over all areas of the Pacific, and at this 

 season, too, there are more or less albacore taken everywhere. Since 

 we have quite a bit of data for the bigeye tuna fishing grounds east of 

 the Marshall Islands on the north side of the boundary between the Counter- 

 current and the North Equatorial Current, we can offer some discussion 

 of this area. 



Although they cannot, in general, be said to be abundant, albacore 

 ajre taken here and at times the catch rates rise above 1.0. These catches, 

 as is shown by the following table, are composed of extremely large albacore. 



Table 13. --Albacore size composition 

 (%) east of Marshall Is., January. 

 Weights in kan = 8. 27 lbs. 



Table 14 shows the frequency of catch rates per day's fishing. 

 The column headed "0" represents the number of times when no albacore 

 at all were taken. This is a rather small percentage of the total number 

 of operations, being about 30 percent in 1951 and about 25 percent in 1952, 



Table 14. --Albacore catch rate frequency, 

 by years, east of Marshalls 



The year. 



1951 

 1952 



5)3 trim. 

 Number of 

 vessels in- 

 vestigated. 



7 

 8 



45 

 25 







} 

 0.25 



95 

 51 



0.25 



J 

 0.50 



13 

 12 



500. 



0. 



I 

 0.75 



1 

 6 



75 



I 



1.00 



1.00 

 1.25 



1.25 

 I 



1.501.75 



1.50 

 } 



Mean. 



0.11 

 0.21 



77 



