SECTION VIII 

 BIOLOGICAL PARAMETERS 



CONCENTRATIONS OF EFFLUENT AT BIOLOGICAL STATIONS 



Figure 26* shows the amount of effluent found at each station from 

 August, 1970 to August, 1971. These averages exclude periods when 

 the desalination plant was shut down. The outer edge of the shaded 

 area represents percentage of effluent present at deeper stations 

 (within the effluent stratum) and the inner edge of the shaded area 

 represents percentage of effluent at the shallower stations. There 

 were no shallow collections at Stations 4 or 8. Station 4 was at 

 the point of effluent discharge and mixing was so active that measure- 

 ments were unreliable. Station 8 was the farthest station from the 

 effluent and the ledge was too shallow to permit two separate stations. 



As pointed out in the section on copper levels, high concentrations 

 of effluent were present at shallow stations for brief periods follow- 

 ing resumption of desalination operations after maintenance periods. 

 Although some such instances were measured, the low frequency of 

 sampling coupled with the irregular times at which the plant resumed 

 operations prevented documenting the movement of the effluent through 

 the shallow stations. Therefore, although the average concentration 

 of effluent at the "A" series stations remained low, transient highs 

 were experienced which compared closely to the average conditions in 

 deeper water. 



Figure 27 shows the mean percent of effluent and the 90 percent con- 

 fidence limits of the mean for all the deeper, series "B", stations 

 from August, 1970 to October, 1971. The series "B" stations showed 

 high effluent concentrations within the entrance canal of Safe Har- 

 bor and a marked reduction in concentrations both in the inner har- 

 bor (Station 1) and in the turning basin (Stations 7 and 9). The 

 average concentration of effluent was negligible at Station 8. 



QUADRAT ANALYSES 



On July 16th, 1970 one-meter square quadrats were set up adjacent to 

 the nineteen stations (Fig* 3). Organisms which were found in the 



*Note that on Figure 26, percent effluent is located two units from 

 the center of the circle on all radii. This is a result of the tech- 

 nique used for isolating the present effluent from ambient variations. 



77 



