Oil Spill Effects 397 



Algae 



One year after the spill on Pond E, the photosynthesis of benthic 

 algae was reduced by more than 50% over the controls (Table 9-3). Only a 

 single measurement was made, however. 



The phytoplankton algae were studied in great detail in the oil 

 experiment ponds. The results are clear; there was some increase in pri- 

 mary production and a change in species. However the causes are difficult 

 to separate into direct toxicity effects and indirect effects due to the killing 

 of zooplankton. This death of zooplankton will be documented later; they 

 are extremely sensitive to oil and were eliminated from Pond E. 



"S 200 



Q. 



O 



E 



100 





 100 



Moy| Jun | Jul | Aug | Sep 



FIGURE 9-6. Primary productivity in Ponds E, Q 

 and C. (After Miller et al. 1978a.) 



