Hanamoto, E. 1974. Fishery oceanography of bigeye 

 tuna - I Depth of capture by tuna longline gear in 

 the eastern tropical Pacific Ocean. La Mer 

 (Bull. Soc. Fr.-Jpn. Oc^anogr.) 12 (3) : 128-136 . 



Shallow longline hooking depths between lat. 

 3 N and 3 s were believed to be influenced by 

 the Equatorial Undercurrent. The swimming 

 layer of bigeye was deeper than the capture 

 depth indicated by longline depth data. 



KEY WORDS: tuna, bigeye, catch, depth, 

 currents, habitat. 



Hanamoto, E. 1975. Fishery oceanography of bigeye 

 tuna - II Thermocline and dissolved oxygen content 

 in relation to tuna longline fishing grounds in 

 the eastern tropical Pacific Ocean. La Mer (Bull. 

 Soc. Fr.-Jpn. Oc^anogr.) 13(2):58-71. 



Areas of high bigeye catch were found in 

 shallow thermocline areas such as off Ecuador 

 and along the equator. Catch rates were low 

 in areas where the top of the thermocline was 

 below 100 m. Depths of capture of bigeye 

 were principally within or below the thermo- 

 cline. 



KEY WORDS: tuna, bigeye, thermocline, 

 oxygen, concentration, temperature, catch, 

 depth . 



Hanamoto, E. 1976. The swimming layer of bigeye tuna. 

 Bull. Jpn. Soc. Fish. Oc^anogr. 29:41-44. [Transl. 

 21 by T. Otsu, SWFC Honolulu Lab. May 1977.] 



Bigeye catch rates varied with depth. Some 



latitudinal differences were noted, but those 



were attributed to water structure (cur- 

 rents) . 



KEY WORDS: tuna, bigeye, depth, habitat, 

 catch, currents, geography, distribution. 



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