ppb 



30 



Ld 



rr 



Ld 



a. 



Id 



l- 



25 



20 



10 



15 

 SALINITY 



20 



37.5 ppb 



2.5 



Ld 



<r 

 tr 



Ld 



a. 



Ld 



75 ppb 



25 



SALINITY 



Figure 12. — Response surface diagram showing predicted respiration rates of the megalops 

 of Rhithropanopeus harrisii acclimated to the test salinities and temperatures 

 and exposed to phenanthrene. Exposure to 37.5 or 75 ppb phenanthrene 

 causes an increase in the sensitivity of the megalops to salinity and a decrease 

 in its sensitivity to temperature. Contour values are given in 

 ml 2 /g dry wt/hr. 



Brooks, J. M., B. B. Bernard, and W. M. Sackett. 



1977. Input of low-molecular-weight hydrocarbons from 

 petroleum operations into the Gulf of Mexico. In: D. A. Wolf 

 (editor), Fate and effects of petroleum hydrocarbons in ma- 

 rine ecosystems and organisms. 



Brooks, J. M., G. A. Fryxell, D. F. Reid, and W. M. Sackett. 

 1977. Gulf underwater flare experiment (GUFEX): Marine 

 effects of hydrocarbons on phytoplankton. In: C. S. Giam 

 (editor), Biological effects of petroleum hydrocarbons, p. 45- 

 75. D. C. Heath & Co., Lexington, Mass. 



15 



