PARENT SESSION
PS6 - Contaminant Effects on Amphibians & Reptiles
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P074) Examining embryological development in snapping turtle hatchlings from the St. Lawrence River Area of Concern.
Ashpole, Sara*,1, Brooks, Ronald1, Bishop, Christine2, 1 University of Guelph, Guelph, Ontario, Canada2 Canadian Wildlife Service, Delta, British Columbia
ABSTRACT- Our study focuses on the potential deleterious effects found in the snapping turtle, Chelydra serpentina, by looking at eight sites along a gradient of contamination. Interruption of normal development, including mortality and malformations, is indicative of a contaminant effect. Study areas and their highest obtained PCB levels include: five sites within the St. Lawrence Area of Concern and the Native Territory of Akwesasne, 60.7 (ng/kg); Hamilton Harbour, 3.4 (ng/kg); the Native Island of Walpole, 0.06 (ng/kg); and as a reference site, Algonquin Provincial Park. A total of 63 clutches were collected, from each subsamples of eggs were analyzed persistent. Remaining eggs were incubated at either a male- or female-producing temperature. Our hypothesis that hatchling turtle mortality will increase with contaminant load was not supported by our ANOVA analysis, but was supported for specific contaminants in our analysis of logistic regression. Suggesting that individual hatchling exposure (by maternal transfer), as opposed to site is a greater contributing factor of mortality. Length of incubation was longer among the female producing treatment, with no difference existing between sites. When comparing the embryonic stages of death in both treatments and across all sites, undetectable embryos occurred the most frequently, especially among Algonquin Park and Cooper Marsh eggs. Accounting for 73% of the low treatment embryos and 45% of the high treatment embryos. Mortality among the remaining embryos most commonly occurred just prior to hatching. Preliminary assessment of our deformity data suggests an increase in deformity complexity and variation exists with greater contaminant load.
Key words: snapping turtle, mortality, deformity, contaminants