PARENT SESSION
PS6 - Contaminant Effects on Amphibians & Reptiles
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P075) Environmental impact on incubation and the embryological development of snapping turtles, Ontario, Canada.
Ashpole, Sara*,1, Brooks, Ronald1, Bishop, Christine2, 1 University of Guelph, Guelph, Ontario, Canada2 Canadian Wildlife Service, Delta, British Columbia
ABSTRACT- Eco-toxicology research conducted on snapping turtles has supported that both hatching success and deformity rates are sensitive biomarkers of persistent organic pollutants. In this study, we examined two contrasting sites, Hamilton Harbour (moderate to high levels of contaminants) and Algonquin Provincial Park (low to non-detectable contaminant levels) and the contribution of handling stress on embryo development. We hypothesize that if undisturbed naturally nested embryos develop in the same manner as those under laboratory conditions, then we would predict that their hatching success and deformity rates to be the same. Our study was designed to compare undisturbed natural nests with artificially incubated embryos. From both sites, nests were either undisturbed and protected or collected. One-third of each collected clutch was redistributed into the following treatments: an artificial buried nest; and artificial incubation at a male- and female-producing temperature. In contrast to our hypothesis, incubation treatment demonstrated a greater contribution to mortality than the effect of site. At both sites, hatching mortality was highest in the rebury treatment. Followed by the high, than the low temperature treatment. Due to very cool seasonal conditions in Algonquin Park, undisturbed nest were unable to develop and comparisons could not be made. Length of incubation within and between treatments was significant. Incubation was shortest at the high, followed by the low then the reburied treatment. Length of incubation was the longest in the in situ nests by double. In all cases, stage at death either occurred very early in development or prior to hatching. Comparisons of deformity rates between treatments and sites are still underway. Our results support that environmental conditions such as moisture and temperature are highly sensitive at influencing development. As such, posing as strong confounding factors when assessing the impact of contaminants on development.
Key words: snapping turtle, mortality, artificial incubation, natural incubation