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

exposed to an action’s effects are not expected to experience reductions in fitness, we
would not expect that action to have adverse consequences on the viability of the
population those individuals represent or the species those populations comprise (Mills
and Beatty 1979; Stearns 1982; Anderson, Phillips et al. 2006). If we conclude that listed
species are not likely to experience reductions in their fitness, we would conclude our
assessment because an action that is not likely to affect the fitness of individuals is not
likely to jeopardize the continued existence of listed species.
If, however, we conclude that listed plants or animals are likely to experience reductions
in their fitness, our assessment determines if those fitness reductions are likely to be
sufficient to reduce the viability of the populations those individuals represent (measured
using changes in the populations’ abundance, reproduction, spatial structure and
connectivity, growth rates, or variance in these measures to make inferences about the
population’s extinction risks). In this step of our analyses, we use the population’s base
condition (established in the Status of Listed Resources and Environmental Baseline
sections of this Opinion) as our point of reference. Finally, our assessment determines if
changes in population viability are likely to be sufficient to reduce the viability of the
species those populations comprise.
Critical habitat analysis focuses on reductions in the quality or quantity of PCEs. The
stressors of the action for this Opinion are chemicals and PCEs potentially affected are
salmonid prey availability and degradation of water quality in freshwater spawning sites,
freshwater rearing sites, freshwater migration corridors, estuarine areas, and nearshore
marine areas. Endpoints evaluated for the prey PCE include prey survival, prey growth,
prey drift, prey reproduction, abundance of prey, health of invertebrate aquatic
communities, and recovery of aquatic communities following pesticide exposure.
Degradation of water quality was evaluated by considering the information available on
the presence of constituents known to adversely affect aquatic organisms (e.g., toxic
chemicals, nutrients, sediments), whole effluent test or toxicity indicator evaluations,
and/or instances of waterbodies not meeting local, state, or federal water quality criteria.
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