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Marine Turtle Newsletter 15:6-7, © 1980

A Preliminary Analysis of Sea Turtle Eggs for DDE

John Fletemeyer
Nova University, Ocean Sciences Dept., 8,000 North Ocean Drive, Dania, Florida 33304, U.S.A.

Four sterile loggerhead sea turtle eggs representing a population of marine turtles nesting during the summer of 1979 on the southeast coast of Florida were analyzed for DDE. This synthetic compound is a metabolite of the globally dispersed and once widely used pesticide, DDT (dichlorodiphenyltrichloroethane). Results revealed that DDE was present in the eggs at the level of 34 ppb (dry basis). Unfortunately the significance of this level of DDE is unknown due to the fact that few investigators have studied the subtle effects of low level DDE contamination in wildlife (mammal or reptile). I believe, however, some concern over this finding is justified because some investigators have found that values from l-17 ppm can result in egg shell thinning in certain species of predatory birds (e.g., falcons). Some investigators suggest that even smaller levels may cause harmful effects.

I hope this report will encourage others with the necessary facilities at hand to conduct more comprehensive studies of this subject. Presently, I do not believe live specimens or fertile eggs should be sacrificed until it can be demonstrated with sterile eggs that synthetic chemical contamination may indeed pose a threat to the sea turtle. Those investigators not directly involved in this research can nevertheless help by carefully documenting deformities in turtles from naturally and artificially incubated eggs from season to season. It should be pointed out that no increase in the visible deformities among sea turtles nesting in Florida has been reported (Witham, pers. comm.). I thank Tom Sullivan and the chemists from the Broward County Environmental Quality Control Board for processing the eggs used in this analysis and Ross Witham for comments.