Risks of Endocrine-Disrupting Compounds to Wildlife: Extrapolating from Effects on Individuals to Population Response

Although this manuscript has been technically reviewed at AED and cleared for publication, it has not be subjected to Agency level review and therefore does not necessarily reflect the views of the U.S. EPA. Mention of trade names, products, or services does not convey, and should not be interpreted as conveying, official U.S. EPA approval, endorsement, or recommendation. Much of the research conducted on the effects of endocrine disrupting compounds (EDCs) has been focused on effects at the individual or subindividual level. The challenge from the point of view of ecological risk assessment is to determine effects on populations and higher levels of biological organization. While there have been some notable cases where field studies were used to demonstrate effects of EDCs on exposed populations in the wild, there has been relatively little research addressing the quantitative linkage between effects at the individual level and effects at the population level. The present study provides an example of linking markers of endocrine effects to indicators of population level effect using basic population models and published data for a fish species often used in laboratory studies, the fathead minnow ( Pimephales promelas ). Additionally, the relation between life history strategy and stressor response is explored using population models for two bird species, European kingfisher ( Alcedo atthis ) and least tern ( Sterna antillarum browni ), with markedly different life history strategies. As these examples demonstrate, populations of species that have different life history strategies can respond differently to a stressor producing responses of similar type and magnitude at the individual level. Matrix population models represent quantitatively the life history strategy of an organism and provide a framework for exploring the risks that EDCs pose to wildlife populations.