CONTENTS 



Page 



Material and methods 1 



Geographical variation in the catch rates 2 



Yellowfin tuna 4 



Albacore II 



Japanese longline fishing 13 



Size of tunas 16 



Sex ratios of the tunas 18 



Vertical distribution of tunas 20 



Improvement of longline gear , 27 



Shark damage to the catch 28 



Summary 29 



Literature cited 30 



Appendix 32 



