BATHYPELAGIC SQUID BATHYTEUTHIS 



123 



Figure 31. — Vertical section, 115°W, 55°-70°S; temperature °C, oxygen concentration 

 ml/L. Capture points of Bathyteuthis abyssicola. 



A huge area of high salinity water, characteristic of the Antarctic 

 Circumpolar Water Mass, lies below the 34.70%o isohaline that tran- 

 sects the 115°W section from 400 m in the south to 2000 m in the north. 

 The large diagonally oriented core of maximum salinity is outlined 

 by the 34.73%o isohaline that encloses two secondary cores of 84.74%o : 

 a small, shallow core to the south and a large, deep core to the north. 



The plot for density shows that the sigma-t value of 27.75 very 

 closely parallels the 34.70%o isohaline (fig. 32). The sigma-t= 27.82 

 line lies about 500 m below this. 



Minimum oxygen values of 4.29 ml/L occur at 400 m at 68°30'S; 

 between ()5°S and 57°S the oxygen minimum values (4.23-4.41 ml/L) 

 occur between 900 and 700 m (fig. 31). At 55° S the oxygen minimum 

 drops to 4.00 ml/L at 1500 m, and there is a broad layer of low oxygen 

 values. Oxygen concentration increases gradually with depth and 

 isopleths slope into deeper water as they pass northward. 



Nineteen captures are plotted on the 115°W sections. Ten were 

 taken during Cruise 15, six during Cruise 19, and one each from 



321-534 O — 69 9 



