SUMMARY 



Fresh water diverted by the demonstration project 

 stimulated primary productivity in the water column 

 and on the sediment surface by importing nutrients 

 required for plant growth and lowering salinity 

 concentrations. During the demonstration period, 

 phytoplankton and microphytobenthos rapidly 

 responded to the inputs of riverine nutrients with 



increased growth rates and accumulation of biomass. 

 The increased primary production rates were especially 

 prominent during periods when sahnit}^ was less than 

 60 psu. The assimilation index {i.e., the relative amount 

 of growth per cell) was also generally higher dunng 

 periods of low salinity, indicating that inherent growth 

 rates were also increased by project diversions. 



4-24 



Water Column Pnductivity 



