CENTRAL NORTH PACIFIC ALBACORE SURVEYS 



JANUARY 1954 - FEBRUARY 1955 



By 



Richard S. Shomura and Tamio Otsu 

 Fishery Research Biologists 

 Pacific Oceanic Fishery Investigations 

 Honolulu, T. H, 



This is the first in a projected series of 

 reports by the Pacific Oceanic Fishery Investi- 

 gations (POFI) on the distribution of albacore, 

 Germo alalunga (Bonnaterre), in the Pacific 

 north of Hawaii. Financial support for the 

 studies was provided under the Saltonstall- 

 Kennedy Act (Public Law 466-83rd Congress). 



Albacore are widely distributed in the 

 tropical and temperate Pacific. They are taken 

 with longline gear along with yellowfin tuna in 

 the central and western equatorial waters 

 (Murphy and Shomura 1953b, Murphy and Otsu 

 1954) and support commercial fisheries in the 

 North Temperate Zone. During the summer 

 and early fall, albacore are taken in commer- 

 cial quantities by trolling and live-bait fishing 

 off the west coast of North America from south- 

 er n Baja California as far north as British 

 Columbia (Clemens 1955). In addition, there 

 are the Japanese fisherieB--a pole-ajid-line 

 fishery operating off the coast of Japan during 

 the early summer and early winter and a winter 

 longline fishery in the area from Japan east to 

 Midway Island (Suda 1954). 



The present paper reports the results of 

 three fishing cruises of the John R. Manning and 

 the incidental catches of four hydrographic cruis- 

 es of the Hugh M. Smith and the Charles H. 

 Gilbert over the period January 1954 to February 

 1955 (table 1). Also incorporated are the catches 

 of a portion of the Japanese albacore fleet that 

 operated in the same or contiguous areas during 

 the survey. The California Department of Fish 

 and Game participated in the first series of alba- 

 core cruises (January-March 1954, table 1), sur- 

 veying west to 140 W. longitude; their results 

 will be published elsewhere. 



Through this and subsequent reports we 

 will use the vernacular names of the fishes. 

 These, with their commonly accepted scientific 

 najnes, are listed in the Appendix as Table 23. 



ACKNOWLEDGMENTS 



We are indebted to fellow stJiff members 

 and officers and crew members of the vessels 

 for their part in carrying out the field work. We 

 would especially like to thank Mr. Toshizo 

 Nomura of the Kanagawa Prefecture Fisheries 

 Experinnent Station for making available Japa- 

 nese catch records. The vertical Jind surface 

 temperature contours were prepared by Mr. 

 T. S. Austin and the writers. Mr. Richard 

 N. Uchida assisted in summarizing the data 

 and Mr. Tamotsu Nakata drew the figures. 



DESCRIPTION OF FISHING GEAR 

 AND OPERATIONAL METHODS 



Two types of fishing, longlining and 

 trolling, were used to sample the North Pacific 

 albacore. The longline method of subsurface 

 fishing was developed by Japanese fishermen. 

 Shapiro (1950) gives an excellent discussion of 

 the history of the gear, and Shimada (1951) 

 gives details on its construction. The gear 

 used for this survey was essentially the same 

 as that described by Mann (1955). A set con- 

 sisted of about 60 "baskets" or skates of gear 

 joined end on end, with 13 hooks on each bas- 

 ket (fig. 1). One half of the gear was set with 

 5-fathom floatlines and the other with 15-fathonn 

 floatlines. Frozen sardine and herring were 

 used for bait on adl three longline fishing 

 cruises. The gear was set at daybreak in a 

 little over an hour. Hauling commenced at 



Table 1 . --Operational data on POFI cruises in the North Pacific, January 1954-February 1955 



