Long-line Catches 



Four long-line trials were very inconclusive; only one albacore was 

 taken by this gear. It was alive when hauled aboard, and was caught on June 2k, 

 360 miles west of Cape Blanco, Oregon, on a surface hook not attached to a long 

 drop line. In addition to the albacore, there were seven blue sharics taken in 

 this set. The other 3 long-line trials caught 15 blue sharks. These results 

 were not encouraging; however, with improved gear and methods and a better londer— 

 standing of oceanic circulation the gear might possibly be uaed for albacore with 

 greater success in waters off the Pacific no^hwest coast. The Cobb used only 

 frozen herring and squid for bait; other baits may prove superior. Only daytime 

 sets were made, vrtiich also may be less effective than sets made at night. Reports 

 of Japanese tuna long lining (which is normally a daj'time fishery in tropical 

 waters) indicate that in certain temperate waters greater catch efficiency is ob- 

 tained if the gear is set in late afternoon and hauled the following morning 

 (Shapiro 1950), 



RELATED OBSERVATIONS 



Size of Albacore 



Length and weight data=/ for troll-caught and gill-net albacore are 

 based on 774-length measurements and 678 weights. The average length was 28 inches 

 (71.1 cm.), and the average weight was 17.1 pounds. Albacore ranged in size frcan 

 22 inches (55.9 cm.) to 35.7 inches (90.7 cm.) and varied in weight frcm 8 to 35 

 pounds . 



Floating gill nets 

 caught somewhat larger albacore 

 than did the surface-trolling 

 gear. The average weight of 

 235 gill-net ailbacore was 18.5 

 pounds as compared with 16. 3 

 pounds for 443 troll-caught 

 fish. It is possible with the 

 conventional trolling methods 

 that some of the larger al- 

 bacore are lost soon after 

 they strike. 



Length frequencies 

 from progressive fishing op- 

 erations and for the entire 

 season are presented in fig- 

 ures 24 and 25. 



I 



FIGURE 23 - ALBACORE WERE MEASURED IN A TROUGH-LIKE 

 WOODEN BOX WITH A METER STICK ATTACHED TO ONE SI^^E. 



In examining the composite histogram for troll-caught fish, three modal 

 groups are suggested. Brock (1944) found that most of the exploited populations 

 of albacore are made up of only a few (mostly 2 or 3) year classes. Canadian 

 studies (Hart and Pike 1948, Hart 1949) pertaining to length frequencies have shown 

 that two dominant length groups are present in the North Pacific fishery; however, 

 Partlo (1950) found four dominant length groups present in 1949. 



2/' ALBACORE WERE MEASURED IN MILLIMETERS FROM THE TIP OF THE SNOUT TO THE CAUDAL FRINGE IN THE 

 CENTER OF THE TAIL. WEIGHTS WERE TAKEN ON A SPRING-TYPE BALANCE AND RECORDED TO THE NEAR- 

 EST ONE-HALF POUND. 



30 



