NON-CONSERVATIVE PROPERTIES 



193 



STATIONS WS990 



SEA MILES I 



OFFSHORE 175 



WS997 



100- 



300- 



150 



_1 



; 



/ 



4-50 

 / 



Fig. 38. Distribution of dissolved oxygen. Section off the mouth of Orange river, 12-14 March 1950, 

 survey I. Positions of stations are shown in Fig. 1. 



STATIONS 

 SEA MILES 

 OFFSHORE 100 

 O 



WS986 



WS989 

 I 



£ 200- 



300- 



400 



Fig. 39. Distribution of dissolved oxygen. Section off Sylvia Hill, 10-11 March 1950, survey I. 



Positions of stations are shown in Fig. 1. 



Here, even with a recorded phytoplankton population of more than io 7 cells (Table 14) the surface- 

 water was only 5-8% saturated with oxygen (cf. Steeman-Nielsen, 1957, p. 75). 



A comparison of the oxygen sections with those of temperature and salinity shows that the low 

 oxygen content exhibits features of distribution similar to those of the upwelling water. Therefore 



