You are here:
RISKS OF ENDROCRINE DISRUPTING COMPOUNDS TO WILDLIFE EXTRAPOLATED FROM EFFECTS ON INDIVIDUALS TO POPULATION RESPONSE
Citation:
Gleason, T R. RISKS OF ENDROCRINE DISRUPTING COMPOUNDS TO WILDLIFE EXTRAPOLATED FROM EFFECTS ON INDIVIDUALS TO POPULATION RESPONSE. Presented at 5th Annual NHEERL Symposium on Indicators in Health and Environmental Risk Assessment, Research Triangle Park, NC, June 6-8, 2000.
Description:
Much of the research conducted on the effects of endocrine disrupting compounds (EDCs) has been focused on effects at the individual or sub-individual level. The challenge from the point of view of ecological risk assessment is to determine effects on populations and higher levels of biological organization (the So What? question). 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 issue of how to assess risks to populations is not unique to EDCs, but is generic to much of the field of ecotoxicology and is an issue now being faced by several of the EP A Program Offices. The NHEERL Wildlife Research Strategy grew out of the need to develop scientifically valid approaches for assessing risks of anthropogenic stressors to wildlife populations. This presentation will demonstrate an approach for applying matrix population models to extrapolate effects at the individual level to effects at the population level. Matrix models are very convenient mathematical tools that quantitatively represent the life history strategy of a species or population. Stressor effects at specific life stages, such as decreased survival probability or reduced reproductive success, can
be directly incorporated into the models. These models can then be solved analytically for a suite of population-level endpoints or indicators, including population growth rate and stable age distribution. In addition to these analytical solutions, matrix models can also be used to conduct simulations to estimate extinction risks and recovery times in a deterministic or stochastic manner. Modeling tools such as these can be used to understand the risks of EDCs to populations of wildlife species, as will be illustrated for piscivorous bird species that have been exposed to endocrine disrupting compounds in the wild.