Assistant Director Nakayama of the Federation of Japanese Tuna 

 Fishermen's Associations for their efforts in behalf of the publication. 



/s/ Motosaku Fujinaga 



Director of the Research Branch 

 of the Fisheries Agency 

 June 6, 1953 



ATLAS OF AVERAGE YEAR'S FISHING CONDITIONS 

 IN THE TUNA LONGLINE FISHERIES 



Editor's Preface 



The study of fisheries resources has come to be a subject of 

 general discussion in recent years, and the significance of this work 

 has gradually come to be correctly understood and highly valued. This 

 is very encouraging to those of us who are engaged in this field, but, 

 on the other hand, it nnakes us feel very keenly the importance of our 

 responsibilities. 



The final objective of the study of fisheries resources is, of 

 course, to make it possible for human efforts to regulate the resource. 

 To put it more plainly, according to nny way of thinking, it is to give 

 the maximum possible production without overstepping the limits of 

 overfishing and to endow mankind broadly and perpetually with the 

 blessings of aquatic products. Or, to state it from the opposite point 

 of view, it is a study of the application of planning to fisheries so as 

 to make planned production possible. 



Our Nankai Regional Fisheries Research Laboratory has been 

 given as its most important mission the carrying out of studies of this 

 sort with regard to the tuna fisheries. It is extremely simple to express 

 our objectives in such phrases as "management of resources" or "planned 

 production, " but it can be judged that this is not an easy task when we 

 consider that even in such limited bodies of water as lakes control of 

 production does not often succeed, or when we take the case of fisheries, 

 such as that for sardines, where the species exploited is produced only 

 from limited areas comparatively near the coasts, and yet cannot be 

 easily accounted for. I think it need hardly be stated how much more 

 this is the case in the tuna longline fishery, the fishing grounds of which 

 extend over broad areas of the open sea, and the catch of which comprises 

 a rather large number of species of fish. 



The approaches which we are using at present in the study of 

 fisheries resources may be very broadly listed as follows: 



