Sewage effluent 



♦ - 



#.# 



-1 i 



0**# Phytoplankton Bloom 



maf^43^ 

 settle 



^ thrives on nutrients 



Dissolved Oxygen 



from wave action 

 & photosynthesis 



D.O. trapped 

 in lighter layer 



Lighter freshwater 



Figure 2-1 . Conceptual model showing the ecological relevance of dissolved 

 oxygen concentration in estuarine water. 



2-3 



