No wetland habitat has been lost in the park in the past century. Currently, only 5 amphibian species remain at Point Pelee National Park. We measured DDE, the primary breakdown product of DDT, in Point Pelee amphibians. Long Point and Rondeau Provincial Parks are similar areas to Point Pelee National Park and are also located on the north shore of Lake Erie. Historic differences in past land-use among these 3 sites are factors affecting amphibian species diversity.
Amphibian declines are a complex and multifaceted problem which defy simple explanations.
Although our evidence implicating contaminants in amphibian decline is correlational, the role of such contaminants should not be overlooked. Because of long environmental persistence, continued toxicity and the potential for long distance atmospheric transport, the effects of organochlorine contaminants can be remote in both space and time. Our research to determine contaminant levels in other amphibian species in the Great Lakes area continues. Organochlorine pesticide residues in southern Ontario spring peepers.