290 



DISCOVERY REPORTS 



FIN WHALES 

 JANUARY 



6 3 Z 6 C ^ 



? 4 2 4 3 8 10 5" v . 



BLUE WHALES 

 JANUARY 



',1 2„— I-' 



r 



^ 





<!\ 



4 5 



Fig. 153. Whale distribution in January and February 1930 (from Kemp and Bennett, 1932). 



values at stations taken in January are shown as blacked-in circles and those in February 

 as open circles. In January there is some, if only slight, correlation between the higher 

 phosphate values and the lower pH values and between the lower phosphate values and 

 the higher pH values. But in February high and low phosphate values all fall within a 

 very limited range of medium pH values, indicating that whilst the reduced phosphate 

 content remains to point to a former phytoplankton production the corresponding high 

 pH values have not been maintained by a continuation of phytoplankton activity, and 

 have been reduced by a restoration of the C0 2 balance by gaseous exchange with the 

 atmosphere. Fig. 1 52 shows the distribution of the average pH values for the top 50 m. ; 

 the area of lower pH values covers roughly the same area as that of the higher phosphate 

 values off the north-east coast, but in addition extends far to the north. It should be 

 noted that the three northern lines, with the exception of the two outer stations on the 

 north-east line, were taken in January. If the hypothesis of animal exclusion is correct 

 we should expect the whale distribution to correspond to the areas of high phosphate con- 

 tent in January but not in February. This is what we find. The whales in February were 

 reduced in numbers and were no longer concentrated off the north-east coast ; this we 



