Factors affecting productivity in fertilized salt water 



455 



detail only in Experiment 1. During this experiment, the values varied greatly, from 

 a low of 0-07 mg/l/day of oxygen to a high of 2-50, mean I 07. standard devia- 

 tion 0*55 (Fig. 1). The mean values for the tanks separately for the period ending 

 just before the fertiHzation of August 11 were 0-74, 0-90, 1-30 and 1-29 in order. The 

 diflFerence between Tank 2 and Tank 3 is significant to the 5% level of probability, 

 but that between Tank 1 and Tank 2 is not quite significant. Tank 1 had been intended 

 as a control, but failure of the caulking between Tanks 1 and 2 permitted some ex- 

 change of water. The increase of phosphorus in Tank 1 was 0-69 Mg at 1 . 



CHLOROPHYLL /yqm/l 



The maximum rate of photosynthesis was reached in hve to twelve days after ferti- 

 lization, and the rate then fluctuated with a general tendency to decrease fhe two 

 Zl h;avily.fertilized tanks remained at a much higher level after the ,n,tK,l max,- 

 mum was achieved. 



VARIATIONS IN PHOTOSYNTHESIS 



The large variations in photosynthesis may be attributed to variations in both 

 popuaion and environment. The relationship between rate of photosynthes. nd 

 Zol factors known to affect it was analyzed; much °f '^e var,M,on ,n P^.^^ 

 synthesis turned out to be attributable to variations ,n chlorophyll, hght. and ph. 

 phate concentration in the w-r^m details now fo ow^^^ ^ ^ ^^^^^,_ 



relS :^:X^^^^^^^'- -= --' "^ -"•" -^ ""'"^'^ 



