0CCURRH4CE OF ALBACORE AND FISHING RESULTS 

 Fishing results of the 1950 albacore exploration indicate the following: 



(1) That early in the season albacore are available to commercial fish- 

 ing methods in the wann offshore water, and the occurrence of the fish fol- 

 lows extension of the warm-water zone shoreward and northward along the coast. 



(2) That albacore may be found far from the center of the fishery over 

 widely scattered areas; and although favorable water temperatures (57° F, 

 and above) and presence of feed affect the movements of the fish, the exist- 

 ence of these two factors does not necessarily insure the presence or avail- 

 ability of the tuna to commercial fishing. 



(3) That fishing with nylon and linen gill nets can produce albacore 

 in substantial quantities, and at times when trolling fails. 



(4) That some of the best fishing may be found along the boundaries of 

 blue and green water or in fingers of wsurm water which extend into the colder 

 green water. 



(5) That the northward limit of available commerciail concentrations of 

 albacore this year was the Queen Charlotte Islands. 



The John N. Cobb catight a total of 1,148 eilbacore in approximately 976 

 hours of actual fishing, or slightly more than on© fish per hour. The total weight 

 of adl fish was roughly 19,000 pounds. Surface trolling accounted for 896 al- 

 bacore, floating linen and nylon gill nets caught 25I albacore, and 1 albacore was 

 taken on long-line gear. 



Indicated Migration Pattern 



From the pattern of early catches made by the Cobb , there is evidence 

 that the albacore, along with the extension of the warm surface-water zone, moved 

 inshore from the southwest and then spread gradually northward along the coastline. 

 The Cobb left Seattle on June 12, and steered a general southwest course from Cape 

 Flattery, Surface water temperatures were cold (52° - 54° F.) past the mouth of 

 the Columbia River and south until a general wanning was noted three hundred miles 

 off the southern Oregon coast. On the evening of June 17, 58 F, water was reached, 

 and the following morning the first albacore were caught on trolled Jigs at a 

 position 42° 12' N. latitude, 135° 05' W. longitude, approximately 480 miles off 

 Cape Blanco, Ore. (see fig. 2). The fish struck at intei^rals, usually in pairs, 

 but no large concentration was fovmd at this time. On running north of the area 

 no fish were taken, and water temperatures declined steadily. An easterly course 

 toward shore revealed still colder water and no fish. On June 23, 5 days later, 

 albacore were again caught in 57° and 58° F. water, which by this time was within 

 three hundred miles of Cape Blanco. Fish were taken in what appeared to be warm 

 fingers of water extending in from the southwest, and surface temperatures as high 

 as 60° F. were encountered in this area during the following few days. A run north- 

 ward showed surface temperattires still as low as 52° F, 320 miles west of the 

 Columbia River on June 26. An extremely rapid warming of the surface waters off 

 the Oregon coast was noted during the last of June and the first few days of Jvily; 

 temperatures as high as 59° F, were fovmd as far north as 35 miles off the mouth 

 of the Columbia River on July 3. At least part of this warming was believed due 

 to extended intervals of sunshine combined with 4 days of fairly steady southerly 

 winds which prevailed at that time. 



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