SUMMARY AND RECOMMENDATIONS 



Although the concentrations of CHs and metals were relatively low in most 

 of the bottlenose dolphins some of these animals had concentrations of 

 contaminants at levels of possible toxicological concem. The concentrations of 

 mercury in the liver samples of two dolphins were elevated. Three animals had 

 elevated concentrations of CHs. Additionally, two dolphins had concentrations of 

 DDTs higher than concentrations of PCBs and die ratio of DDT to DDE, one of 

 its breakdown products, may indicate a possible exposure to recently released 

 DDT in three dolphins. 



Because of the concem and awareness that chemical contaminants may act 

 directly or indirectly to bring about consequences deleterious to the health of 

 these dolphins, we need to better understand the extent of contamination and 

 effects of these pollutants on marine mammals that frequently suffer from mass 

 strandings. Various endogenous factors (age, sex, lipid content of tissues, 

 reproductive cycle) and enviromnental factors (sources and types of 

 contaminants) need to be systematically investigated widi good quality samples 

 from a significantly larger number of stranded animals. If possible, samples such 

 as small portions of blubber from wild populations (non-stranded) would be 

 useful in evaluating contamination levels in apparently healthy animals. It is 

 essential to continue to generate a scieiitlfically credible and comprehensive data 

 base on types and concentrations of contaminants and possible biological effects in 

 marine manunals using state-of-the-art procedures with quality assurance 

 measures. 



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