given by McGary and Stroup (MS)1/. Briefly, it 

 is an area of mixing created by shearing action 

 between two easterly flowing currents, the Aleu- 

 tian Current (relatively cold and low salinity 

 water) to the north and the North Pacific Current 

 (relatively warm and high sadinity water) to the 



— McGary, James W. cuidE. D. Stroup. 

 Mid-Pacific oceanography, Part VIII, Middle 

 latitude waters, January-March 1954. The authors 

 point out that an ade quate name for this zone has yet 

 to be found. It has at times been calledthe Arctic 

 Convergence and the North Polar Front. 



south. The zone is characterized by abrupt 

 changes in temperature and salinity and by an 

 increase in inorganic phosphate as compared 

 with the North Pacific Current (McGary and 

 Stroup MS). Increased biological activity is 

 suggested by somewhat lower water trans- 

 parency values (fig. 4) than prevail to the 

 north jind south. 



Nearly all of the troll-caught albacore 

 were taken within the trcinsition zone (fig. 4), 

 and the longline -caught albacore were taken 

 either in the transition zone (fig. 5A) or just 

 to the north (figs. 5B, 5C), suggesting a close 



80 



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100 



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o 

 o 



X 



|i I III u I III I ! 1 1 



r T k -I i^i 



n — I — 1 — I — I — I — I — I — I — I — I — I — I — I — I — I — I — r 



J I I I I I L 



NORTH LATITUDE 



Figure 5A.- -Vertical temperature sections and longline 

 catch of albacore (catch/100 hooks) along 160 W. longi- 

 tude during the three survey periods, Manning cruise 19, 

 January-March 1954. 



10 



