MP10 PCB Toxicity in Aquatic Organisms- Endocrine Effects
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(EIS-1116-596103) PCB exposure in snapping turtles: effects on growth, metabolism and behavior.

Eisenreich, K¹, Kelly, S¹, Rowe, C¹, ¹ University of Maryland Center for Environmental Scienc - Chesapeake Biological Laboratory

ABSTRACT- Subtle changes in thyroid activity can significantly alter developmental processes due to the extreme sensitivity of embryos/fetuses to thyroid hormones. While the thyroid plays a major role in growth and metabolic processes, it also regulates neurological development. Thus, maternal transfer of PCBs to developing offspring would be expected to impair neurological development, with potential effects on learning and behavior. We examined the individual and interactive influences of maternal contributions of PCBs and food-bourne PCBs in natural prey items on snapping turtles (Chelydra serpentina) in the Hudson River Superfund site over the first year post-hatching. Measurements of carapace length and width, plastron length, and wet mass were used to quantify growth differences between hatchlings from different exposure regimes. In addition, respirometry was used to examine how potential metabolic anomalies correlated with PCB-related thyroid effects. Finally, four behavioral assays were conducted to identify potential relationships between thyroid-mediated neurological development processes and correlates with individual fitness. Behavioral assays included response to a physical stimulus and escape speed, response to a visual stimulus, righting response, and foraging success. While measurements of thyroid hormones in the juveniles have not yet been conducted, data on circulating thyroxine levels in adult turtles from the Superfund site and nearby reference sites will be presented. As PCBs perturb the thyroid system with the same mechanistic pathways in all life stages, the adult data will serve as a surrogate metric for thyroid hormone levels in the juveniles.

Key words: Chelydra serpentina, Behavior, Growth, PCBs