Summary

Description

Between 1998 and 2000 Alligators in Lake Griffin, Florida, demonstrated unusually high mortality that was thought to be associated with the lakes hyper eutrophic and possibly contaminated condition. We have conducted preliminary analysis of Organochloride and heavy metal levels in tissues of American alligators and also examined several other factors that may have affected alligators in Lake Griffin and Lake Woodruff. The results of these investigations suggest that the levels of organochloride and toxic metal contaminants on both Lake Griffin and Lake Woodruff are at background levels and are insufficient to explain the observed mortality of alligators. Alligators in each lake demonstrate differing patterns of low OC residue that are thought to reflect the different history and locations of the lakes. We have also examined and eliminated disease Botulism, viral infection including West Nile Virus, bacterial infection and direct effects of toxic blue green algae as causes of alligator mortality. We have also made a comparison of the diet of alligators in the two lakes and conducted a detailed pathology investigation. Separate studies published elsewhere suggest that a dietary deficiency of thiamin induced by a diet of thiaminase rich Gizzard shad Dorosoma cepedianum contributes to the observed mortality of alligators in Lake Griffin. However, additional factors including blue green algal toxins and contaminants are still under investigation.