PIIYTOPLANKTON AND HYDROLOGY 79 



method of Kreps and Verjbinskaya is of great interest because it eliminates the draw- 

 backs, already referred to, involved in estimating phytoplankton production either by 

 counting numbers of plant cells or by measuring volumes. 



Table VIII 



Comparison of phosphate and oxygen content of the top 50 m. on a line of five stations taken 

 off the north-east coast of South Georgia in August 1928 and again four months later 



Station ... 



Depth in m. 

 o 



5 



10 

 20 



30 



40 



5° 



Average 



o 



5 

 10 



20 



3° 

 40 



50 



Average 



Grand average 



August 27-28, 1928 



WS 

 257 



H3 

 142 

 146 

 146 

 146 

 140 



133 



WS 

 258 



WS 



259 



WS 

 261 



P 2 5 mg. per cu.m. 



142 



WS 



263 



136 



!3 2 



J33 

 130 

 163 

 162 

 160 



H5 



Oxygen : cc. per litre 



7-78 

 778 

 776 



777 



7-94 

 7-84 

 7-80 



7-86 



779 

 8-03 

 7-84 



7-89 



7-95 



7-89 

 8-oi 



7'95 



7-96 



8-02 

 7"94 



7-97 



P 2 5 = 149 mg. per cu.m. 

 O = 7-89 cc. per litre 



December 27-28, 1928 



WS 

 328 



102 

 106 

 102 



102 

 107 

 11 1 



"5 



WS WS WS 



329 330 332 



P 2 O s mg. per cu.m. 



106 



WS 



334 



112 



IJ 7 

 119 

 119 

 119 



"7 

 120 



118 



Oxygen: cc. per litre 



8-05 



8-24 



8-02 



8-io 



8-31 



8-17 



8-o8 



8-19 



8-15 



8-26 7-89 



8-i3 8-54 



8-12 



8-13 



8-53 



8-44 



8-03 



7-93 



P 2 O s = 112 mg. per cu.m. 

 " O = 8-16 cc. per litre 



Fig. 39 shows a chart of the phosphate content expressed as an average for the top 

 50 m. round South Georgia in the December-January survey, 1926 7. Arrows in- 

 dicating the main water movements are shown, but the figure should be compared with 

 the details in Fig. 6. The general similarity in the pattern of both the phosphate and 

 the phytoplankton charts (Figs. 38-40) is striking, the areas of greatest phosphate 

 reduction corresponding with the greatest phytoplankton production. 



We will now consider the relationship of phytoplankton production and phosphate 

 reduction in this survey in greater detail, taking each of the lines of stations with their 

 adjacent intermediate stations separately. These lines are referred to as A, B, C, D, E, 

 F and G, corresponding to the lettering used in the temperature and salinity charts in 



