Organic contaminants in snapping turtle (Chelydra serpentina) populations from southern Ontario, Canada
Organochlorine contaminant levels were measured in 78 adult snapping turtles collected from 16 sites in southern Ontario, Canada in 1988/89 to evaluate the risk to humans of consuming snapping turtles. Significant differences in turtle contaminant levels were observed among sites. Mean levels in muscle, at all sites, were below fish consumption guidelines for total polychlorobiphenyls (PCBs), total DDT and mirex. However, contaminant levels in older turtles from some sites exceeded guideline values. Multivariate statistical techniques indicated the existence of a highly significant relationship between contaminant levels in adult female turtles and their eggs. Multivariate techniques also identified differences in contaminant composition in adult snapping turtles from sites in the Great Lakes where differences in reproductive success have been previously observed. The mono-ortho substituted PCB congener 2,3,4,3′,4′-pentachlorobiphenyl (IUPAC #105) may be an important contributor to the toxic burden of snapping turtle populations.
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