EFFECTS OF MAN-MADE POLLUTION ON 

 THE DYNAMICS, OF CORAL REEFS 



by 



Lawrence R. McCloskey 



Systematics-Ecology Program 



Marine Biological Laboratory 



and 



Richard H. Chesher 



Westinghouse Ocean Research Laboratory 



ABSTRACT 



Respiration, feeding, and other activities of corals were monitor- 

 ed 22 situ near the TEKTITE site. Artificial, short-term dosing of 

 reef corals with a mixture of chlorinated hydrocarbons (p,p'-DDT, 

 dieldrin, and Aroclor 1254) produced a significant decrease in 

 photosynthetically-generated oxygen production. When subjected 

 to a 1 ppm mixture of these compounds, all corals tested exhibited 

 an increase in the compensation values, and a decrease of 12 to 

 227o in the photosynthesis to respiration proportion. Photosynthesis 

 remained depressed up to four days after dosing. No other changes 

 in dosed corals were observed. It appears unlikely that coral 

 reefs have yet been deleteriously affected by present residues of 

 organo-chlorines . 



INTRODUCTION 



Evidence from a previous study on a primary coral predator, Acanthaster 

 planci , led us to believe corals may sometimes contain significant residues 

 of several chlorinated hydrocarbon compounds (McCloskey & Deubert, in 

 press) . In preparation for our participation in TEKTITE II we determined 

 (1) the types and present quantities of chlorinated hydrocarbons in sea 

 water and coral tissue taken from Key West, Florida; and (2) the uptake 

 rates of doses of chlorinated hydro-carbons administered to two species of 

 corals. From this, and the information on organochlorines in Acanthaster , 

 we selected for further experimentation the three most abundant organo- 

 chlorines -p,p' -DDT , dieldrin, and Aroclor 1254 (a PCB) . From the uptake data 

 we determined the dose times and concentrations to be used. 



OBJECTIVES 



For our mission in TEKTITE, we outlined these objectives: 



(1) determine present residue levels in a variety of reef corals; 



(2) determine the uptake rate, internal dispersal, and abatement 

 rates (i.e., decrease in residue load with time, through 

 metabolism or exchange of the compounds with the environment) 

 of artificially administered doses of chlorinated hydrocarbons 

 in corals; 



VI-229 



