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

Effects of the Proposed Action
The analysis includes three primary components: exposure, response, and risk
characterization. We analyze exposure and response, and integrate the two in the risk
characterization phase where we address support for risk hypotheses. These risk
hypotheses are predicted on effects to salmonids and designated critical habitats’ PCEs.
The combined analysis evaluated effects to listed Pacific salmonids and their designated
critical habitat (see Approach to the Assessment).
Exposure Analysis
In this section, we identify and evaluate exposure information from the stressors of the
action (Figure 1). We begin by presenting a general discussion of the physical and
chemical properties of carbaryl, carbofuran, and methomyl that influence the distribution
and persistence of action stressors in the environment and exposure of listed species and
designated critical habitat (structures shown in Figure 36). Next we present general life
history information of Pacific salmon and steelhead and evaluate the likely co-occurrence
of action stressors with the listed Pacific salmonids. We then summarize exposure
estimates presented in the three BEs and present other sources of information, including
other modeling estimates and monitoring data to further characterize exposure to listed
species and designated critical habitat. Finally, we conclude with a summary of expected
ranges of exposure and the uncertainty contained in the exposure analysis. Because the
ESA section 7 consultation process is intended to ensure that the agency action is not
likely to jeopardize listed species or destroy or adversely modify critical habitat, NMFS
considers a variety of exposure scenarios in addition to those presented in EPA’s BEs.
These scenarios provide exposure estimates for the range of habitats utilized by listed
salmonids.
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