Shrimp boat antifouling paint, therefore, did contribute to the level 

 of copper in the boat basins but this source did not affect the level 

 of copper in the canal. The desalination plant after starting opera- 

 tion contributed about half of the copper excess in the boat basin 

 and essentially all of the excess nickel. The desalination plant was 

 the source for the excess copper and nickel in the canal. 



Sediment samples taken in and around the Safe Harbor area showed that 

 excessively high copper levels were confined for the most part to the 

 harbor and turning basin. Copper concentrations about 300 percent above 

 the historical average, extend 400 feet (122m) west of the turning 

 basin where the well-mixed effluent water flows out of the Safe Harbor 

 (Fig. 20). 



A similar copper level analysis was performed on sediments surrounding a 

 desalination plant discharge in the Virgin Islands. The results of 

 these data showed that the effluent path could be traced using copper 

 in the sediments even though copper discharge was low and the effluent 

 floated rather than sank (Chesher, manuscript in preparation). 



FORAMINIFERA 



The foraminiferan fauna from the various sediment strata was examined 

 for species diversity and numbers of individuals per cc of dry 

 sediment. A species list of all Foraminifera found in the cores is 

 presented in Table IV. Presence or absence of a particular species in 

 the core strata is indicated as well as the time when the desalination 

 plant began operating. Several species appeared and disappeared in 

 the course of time, but there was no marked reduction in the number of 

 species. In fact, 75 percent of the species present in 1955 were 

 still present in September, 1970 and the number of species had increased 

 from 48 in 1955 to 51 in 1970. Some species may have been excluded due 

 to high copper levels. Note, for example, the distribution of Elphidium 

 advenum, Pyro subsphaeriaat Rosalina rosea, Quinquelooulina agglutinans, 

 Trilooulina rotunda, and Trilooulina planoiana (Table IV). Fursenkoina 

 mexiaania, on the other hand, was found only in high copper sediment 

 samples. The figure on species diversity (Fig. 24) shows little 

 similarity to the graphs of copper and nickel distribution (Figs. 22 

 and 23). It is possible that the initial drop in species diversity 

 during the second year of the operation of the desalination plant 

 reflected a period of faunistic adjustment. The decline in species 

 diversity in the core from Bay 2, however, began well prior to the 

 construction of the desalination plant and continued unchanged 

 through the initial period. Probably the fluctuations in species 

 diversity were natural and unrelated to the plant. 



Numbers of Foraminifera per cc of dry sediment are plotted in Figure 

 25. The core from Station 3, off the desalination plant sea wall. 



70 



