OF 
S 
c 
0 
PN 
IOO 
OF 
s 
c 
POC 
1 -J 
250 500 
OF 
S 
C 
chlorophyll a 
_i_—i 
2 4 
OF h 
S 
C 
0 
microzooplankton 
dry weight 
250 
500 
OF 
s 
c 
0 
macrozooplankton 
dry weight 
Too 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 4x10^ 
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 
352 
