Project Summary (2000-2006)

Project investigators are focusing on the role of bioaccumulating organochlorine pesticides on top predator species (alligators and largemouth bass), in which associations between reproductive failure and exposure to these substances has been documented. The project goal is to identify toxic endpoints and populations sensitive to chlorinated hydrocarbon (CHC) toxicity, which are known to be endocrine disruptors. Results to date indicate that reproductive failure in these species results largely from decreased embryonic and neonatal viability, and that these effects are closely associated with wetland restoration of formerly chemical laden agricultural areas. Effects of exposure to CHCs are being studied using molecular, biological, histological, endocrinological, and toxicological analytical techniques to evaluate embryo development, egg composition, and neonatal health and endocrine function of these animals in central Florida lakes. Project investigators are conducting laboratory and field experiments to help define the cause of reproductive failure, and they are establishing causal links between specific adverse effects and exposure to CHCs. Also under investigation are the direct and multi-generational effects on the reproductive success, endocrine function, and sexual differentiation in the largemouth bass, and its association to CHC exposure.