ANTARCTIC SURFACE WATER 



Si 



stations on the two lines, Sts. 1328 and 1331, for example, are respectively 117 and 79 mg. 

 This difference of phosphate values must be due to earlier differences in concentration 

 of phytoplankton in the far south of each line of stations. It cannot be said that the 

 phosphate content disparity is due to differences of concentration of phytoplankton 

 in situ because at both stations the phytoplankton catches in late March and early April 

 were negligible. Nevertheless I think that there had been some influence of Weddell 

 Sea water in the surface layer at St. 1328, the most southerly station south of the 

 Falklands, because the mean value of the 0-100 m. layer silicate content was so much 

 greater than that of the stations north of it. 



The absence of December or January observations prevents any estimation of the 

 net withdrawal of phosphate in these observations. 



SEASONAL VARIATION OF SILICATE IN THE SURFACE 

 LAYER IN THE SCOTIA SEA 



The available data are restricted to a line of stations between South Georgia and the 

 Falklands, three sets of observations from the South Orkney Islands northwards to the 



LATITUDE 

 STATION 



60°5 



SB" 



56° 

 I* 



54 



rial en 

 S2 D 



jan 1 1 oct Tap 



Ito4-!33S 

 52° 



in rig 

 in <T^ 



W 2000- 



a 

 (J) 



s 



ID 



O APRIL 1934 

 X OCTOBER. 1934 

 A JANUARY 1935 



JANUARY SURFACE 



Fig. 14. Surface silicate content and the average silicate content of the o-ioom. layer from the South 

 Orkney Islands northwards to the Antarctic convergence. 



Antarctic convergence, and two lines of stations between the Falklands and Elephant 

 Island. 



Between South Georgia and the Falkland Islands in October 1934 the surface value 

 of silicate content was of the order 1000 mg. in the Antarctic zone. North of the South 

 Orkneys the observations were made in January, April and October and are shown in 

 graphical form in Fig. 14. As with the phosphate distribution, the silicate content in 



7 2 



