PARENT SESSION
TA2 - Wildlife Toxicology
Chair: Bishop, Christine1, 1 5421 Robertson Road, Delta, British Columbia, CANADA
Co-chair: Elliott, John1, 1 5421 Robertson Road, Delta, British Columbia, CANADA
8:00 AM to 12:00 PM - Tuesday, 19 November 2002
Room Ballroom J
(341) An evaluation of the incidence of embryonic mortality in the American Alligator from contaminated sites in Central Florida.
Wiebe, Jon*,1, Sepulveda, Maria2, Harvey, Alfred2, Ruessler, Shane1, Rauschenberger, Heath2, Buckland, Janet, Gross, Timothy1,2, 1 Florida Caribbean Science Center - USGS-BRD, Gainesville, Florida, USA2 University of Florida - Department of Physiological Sciences, Gainesville, Florida, USA
ABSTRACT- Our laboratory has been examining the relationship between maternal and egg exposure to chlorinated hydrocarbons (CHC) and subsequent reductions in American Alligator (Alligator mississippiensis) egg and embryo quality. Current research examined the incidence and identified the developmental stage of embryonic mortality on several sites with intermediate to high concentrations of (CHC) contamination. Sites included: Eustis Muck Farm (a reclaimed agricultural property with high CHC contamination), Lake Apopka (site of high CHC contamination / superfund site), Lake Griffin (site of intermediate CHC contamination), and Lake Lochloosa (control site). Though > 50% of all nests sampled from contaminated sites had a hatchability rate near the state average of 65%, incidence of developmental toxicity continues to be a prevalent condition on the afore mentioned contaminated sites. However, the ability to establish a cause and effect relationship between CHC egg exposure and subsequent embryonic mortality has been limited. Embryonic mortality was defined by two developmental stages: early (day 1 to day 30) and late (day 31 to hatch). However, these data suggest that the sites appear to be experiencing differential CHC exposures and subsequently exhibiting non-uniform patterns of embryonic mortality. Eustis Muck Farm exhibited significant increases in early and late embryonic mortality. Lake Apopka exhibited a higher incidence of unbanded eggs, an indicator of pre-ovipositional mortality. Lake Griffin exhibited increased incidence of late embryonic mortality. These results do not indicate a cause and effect relationship with CHC exposure in eggs and subsequent increases in embryonic mortality. Our laboratory is examining the influence of CHC compounds on female alligator ovarian function, nutritional, nutrient, non-target compounds, and chemical mixtures exposure and subsequent reductions in egg and embryo qualities. (Funded by NIEHS-SFBRP).
Key words: Endocrine Disruption, Wildlife Toxicology, American Alligator, Embryonic Mortality