American Crocodile Contaminant Monitoring
An Apparent Case of Pb Toxicosis in an American Crocodile in South Florida
Lead contents removed from stomach of deceased crocodile
On November 17, 2023, an FWC Crocodile Response Agent responded to a call about an American crocodile that had climbed into an outdoor swimming pool. The crocodile was captured and a GPS transmitter was attached as a part of FWC’s Urban Crocodile Project. Unfortunately, the crocodile died unexpectedly after the attachment process, so FWC biologists performed a field necropsy and collected relevant samples to learn what had happened.
The stomach contents of the deceased crocodile contained 22.4 g of lead (Pb), including one fishing weight and 23 Pb air rifle pellets. The remains of at least one green iguana were also discovered among the stomach contents. An analysis of tissue samples revealed elevated Pb levels, leading researchers to believe that the crocodile was suffering from Pb toxicosis. The crocodile was also observed to be missing most of its teeth, a clinical sign of Pb toxicosis.
The mouth of an American crocodile with healthy dentition shown in comparison to an American crocodile suspected to be experiencing Pb toxicosis
As a follow-up to this incident, FWRI has begun a contaminant monitoring project, opportunistically collecting a variety of tissue samples to better understand the impact contaminants, like Pb, on Florida’s native crocodiles and the extent to which these contaminants pose a threat to the population.
Stay tuned to learn more about our research.
Read the open access note about the unexpected crocodile mortality event.