10. Foraminifera shells left a permanent record of changes in 

 sediment fauna from pre-plant conditions to the present. 

 This record indicated that the foraminifera populations 

 had increased substantially over pre-plant densities. Num- 

 bers of species did not change significantly. 



11. Densities of live foraminifera decreased in the immediate 

 vicinity of the discharge but, in general, were higher in 

 Safe Harbor than at control stations. Conditions improved 

 for foraminifera during the cooler months. 



12. Shallow stations near the desalination plant were exposed to 

 high concentrations of effluent following shut-down periods. 

 Sudden, large doses of ionic copper, produced as the plant 

 began operation or changed operational modes were more dele- 

 terious than steady-state conditions. 



13. Copper and temperature were the two major deleterious as- 

 pects of the effluent. High discharges of copper resulted 

 in mortality of test organisms at in situ bioassay stations. 



14. In situ bioassays showed echinoids and ascidians were more 

 sensitive to the effluent than stone crabs or gorgonians. 

 A concentration of only 1.5 percent effluent was lethal to 

 echinoids in long-term studies. Gorgonians survived brief 

 exposures to five percent effluent and stone crabs survived 

 exposures to six to seven percent effluent. 



15. Asoidia nigra was the most sensitive organism to effluent 

 in laboratory acute toxicity experiments; fifty percent 

 dying in 96 hours in 5.8 percent effluent. Echinoids had 



a 96-hour TLm of 8.5 percent effluent; stone crabs a 96-hour 

 TLm of twelve percent effluent. Photosynthesis of Thalassia 

 testudinum was reduced by fifty percent in twenty-four hours 

 in concentrations of twelve percent effluent. 



16. Fewer specimens of diatoms and protozoans settled on dia- 

 tometers in effluent- laden water but diversity was not signifi- 

 cantly decreased. Vortioella sp. and Nitzsohia longissima 



had higher population levels on Safe Harbor shallow water 

 diatometers and lower populations in deep water diatometers 

 when compared to control stations. 



17. Plankton populations were reduced in deep, effluent-laden 

 Safe Harbor water when compared to shallow water and con- 

 trol stations. 



18. Serpulids were more abundant in Safe Harbor than at control 

 stations but their numbers were reduced by effluent-laden 

 water in the immediate vicinity of the discharge. 



