15 



BUREAU OF COMMERCIAL FISHERIES PROGRAMS 



North Pacific Fishery Investigations 



RESULTS OF SALMON 



RESEARCH CRUISES, SUMMER 1966 



BCF conducted three research cruises in 

 the North Pacific Ocean during June -Septem- 

 ber 1966. The objectives: to study distribu- 

 tion and relative abundance of immature sock- 

 eye and chum salmon, compare indices of 

 relative abundance from catches of gill nets 

 and purse seines fished simultaneously, and 

 to determine the percentage of salmon lost 

 from gill nets during fishing (dropouts). 



These cruises, which represented the 

 Seattle Biological Laboratory's greatest ef- 

 fort in manpower and vessels in several 

 years, were terminated in early September 

 after successfully accomplishing their major 

 objectives. 



The charter vessels Paragon and St.. Mi - 

 chael and the Bureau's George B. Kelez 

 fished gill nets of various meshes. Typical- 

 ly, a string of gear consisted of 12 to 14 50- 

 fathom s hac k le s of 2|- and 3^ -inch mesh, 

 and 12 to 16 of 4j- and S^-inch mesh 

 (stretched measure). 



A total of 119 gill net sets made in the 

 three sampling areas (chart) produced a 

 catch of 15,750 salmon and steelhead trout. 



175° 180° 175° 170° 165° 160° 155° 150° 



Fq — r 



55' 



50- 



UNALASKA ISLAND 



ADAK ISLAND 



;yuf^ 



*<SW 



PoroQon 



Areas fished by U. S. research vessels George B. Kelez, Paragon, 

 and St, Michael, June -September 1966. 



Sockeye salmon were predominant near Adak 

 Island (Paragon), whereas chum salmon domi- 

 nated along long. 167° W. (George B. Kelez) 

 and long. 158° W. (St. Michael). 



Previous studies showed that in the summer 

 immature sockeye and chum salmon in these 

 areas are generally present to lat. 49° N. 

 Thus, near Adak Island, these species are 

 found to a distance of 150 miles offshore; at 

 long. 167° W., they are caught nearly 260 

 miles from shore and, at long. 158° W. , they 

 are present to approximately 430 miles off- 

 shore. 



South of Adak Island, along long. 176° W., 

 1 -winter-at-sea immature sockeye salmon 

 were most abundant 31-45 miles offshore 

 (lats. 51O30' N. to 51°00' N.), although abun- 

 dance was only slightly less to 60 miles off- 

 shore. Abundance was at a peak July 1-10 

 and July 21-31. Fishing south of Unalaska 

 Island, along long. 167° W., indicated that 

 these young sockeye salmon were about equal- 

 ly abundant throughout the summer; their peak 

 abundance occurred 90-180 miles from shore 

 (from lats. 52°30' N. to 50°30' N.), Similar- 

 ly, along long. 158° W., no peak of abundance 

 of 1 -winter-at-sea sockeye was detected. 

 This age group occurred throughout the sam- 

 pling area. 



The older immature sockeye salmon (2- 

 and 3 -winters-at-sea) were distributed some- 

 what differently from the younger fish. South 

 of Adak, these older fish were most abundant 

 31-90 miles from shore (lats. 51°00' N. to 

 50°15' N.); catches were too small, however, 

 to demonstrate significant peaks of abundance. 

 To the east, the older sockeye salmon along 

 long. 167° W. predominated in the same area 

 as the younger fish (90-180 miles offshore); 

 they were more abundant late than early in 

 the sampling season. In contrast, older sock- 

 eye salmon along long. 158° W. were abun- 

 dant during early and late August and pre- 

 dominated from 260 to 360 miles (lats. 52O30' 

 N. to 50°30' N.) south ofthe Alaska Peninsula. 



Catches of chum salmon (age -2 immature) 

 along long. 176° W. were greatest from July 

 1-10 in an area 31-45 miles offshore. Along 

 long. 167° W,, however, few young chum salm- 

 on were caught and no period of peak abun- 

 dance was detected. At the easternmost fish- 

 ing stations (158° W. long.), 2 -year-old chum 



