Organochlorine pesticides, PCBs, trace elements and metals in western pond turtle eggs from Oregon

With increased concern over the status of reptile populations globally, contaminant studies should be part of species evaluations. We analysed eggs of western pond turtles (Clemmys marmorata) from Fern Ridge Reservoir in western Oregon (USA) for 20 organochlorine (OC) pesticides or metabolites, 42 congener-specific polychlorinated biphenyls (PCBs), and 16 trace elements or metals. These eggs represent the first of this species analysed. The OC pesticides and PCB residue concentrations in the western pond turtle eggs were generally low and similar to those found in eggs of snapping turtles (Chelydra serpentina) from a remote site in Ontario, Canada. Western pond turtle eggs also contained mercury and chromium, which are metals of special concern. Although few reptilian eggs have been analysed for metals, the 44.9 micro g/g dry weight chromium in a western pond turtle egg in this study may be the highest reported in a reptilian egg. We found no significant difference in contaminant concentrations in eggs from nests in Oregon, where all turtle eggs failed to hatch compared to those where some eggs hatched. During this initial project, however, we were unable to assess fully the role of OCs, PCBs and other contaminants in the western pond turtle decline. Factors other than contaminants may be involved. In another study, snapping turtle eggs near the Great Lakes-St. Lawrence River basin were much more contaminated with evidence reported of effects on sex differentiation and reproductive endocrine function. Egg hatchability, the only reproductive parameter monitored, may not be the most sensitive endpoint. Other endpoints, including endocrine function, deformity rates, growth rates, and sex determination must be studied.Henny et al "Organochlorine pesticides, PCBs, trace elements and metals in western pond turtle eggs from Oregon." Northwest Science. 2003; 77(1): 46-5