OF - 

 S- 



c- 



OF 



s 



c 



OF 



PN 



s- 



c- 



POC 



50 



100 



250 



500 



OF 



chlorophyll a 



microzooplankton 

 dry weight 



250 



500 



OF 



s- 

 c- 



macrozooplankton 

 dry weight 



100 200 



ALL UNITS ARE mg/m^ 



Figure 23-5. Concentration of Selected Water Quality Variables. 

 NOTE: Symbols explained on Figure 23-4. 



the following points: (1) there is net phosphorus dispersal from the outfall to 

 the southeast sector, and from the southeast sector to the central sector; and 

 (2) nitrogen flux occurs from the outfall to the southeast sector, but 

 insignificant from there to the central sector; and (3) there are also fluxes of 

 the various particulate materials (Figure 23-5). 



Quantitatively, just how significant are these fluxes? The mean residence 

 time of water in the southeast sector of Kaneohe Bay has been variously 

 estimated but is apparently about 20 days (10). The volume of the southeast 

 sector is about 80 x 10 m^, so the daily exchange volume is about 4 x 10 

 m /day. Table 23-3 summarizes nitrogen and phosphorus fluxes calculated 

 from the concentration gradients and exchange volume, and compares these 

 fluxes with input rates of "new" nitrogen and phosphorus. There is a dramatic 

 imbalance between stream plus sewage input to the southeast sector, and 

 advective output from that sector. The calculation is not entirely accurate, 

 because some material is known to pulse from the southeast sector in a 



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