Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

sustaining in the natural environment (McElhaney, Ruckleshaus et al. 2000; McElhaney,
Chilcote et al. 2007).
In determining the effect of an action to populations, we first address whether individual
fitness level consequences are likely and whether those consequences affect populations.
We evaluate whether identified VSP parameters of populations such as abundance and
productivity are reduced by individual fitness effects. If populations are likely to be
adversely affected by reductions in VSP parameters, we analyze the potential effects to
the species as a whole. In parallel, if designated critical habitats are likely to be exposed
and PCEs are adversely affected, then we evaluate the potential for reductions in the
conservation value of the habitats. We devise risk hypotheses based on identified PCEs
that are potentially affected by the stressors of the action. If the best available data
indicate that PCE-specific risk hypotheses are supported, then we discuss whether critical
habitat will remain functional to serve the intended conservation role for the species in
the Conclusion section.
General conceptual framework for assessing risk of EPA’s pesticide actions to listed
resources.
We evaluate the risk to listed species and designated critical habitat in the Effects of the
Proposed Action section by applying an ecological risk assessment framework that
organizes the available information in three phases: problem formulation, analysis, and
risk characterization (EPA 1998; McElhaney, Ruckleshaus et al. 2000). We adapted the
EPA framework to address ESA-specific considerations (Figure 2). The framework
follows a process for organizing, evaluating, and synthesizing the available information
on listed resources and the stressors of the action. Below, we briefly describe each phase
in the Effects of the Proposed Action section.
Problem Formulation
The first phase of the framework is problem formulation. In this phase, we generate
conceptual models from our initial evaluation of the relationships between stressors of the
action (pesticides and identified chemical stressors and potential receptors (listed species,
habitat). We represent these relationships in conceptual models presented as diagrams
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