Discovery Institute's Environmental Policy
Initiative
Recovery Plans under the ESA are founded
on the premise that we have some capacity to manage the populations. Therefore,
the process that connects the decision to list a population under ESA with
the decision to remove it from the list should include an evaluation of what
was
broken, implementation of actions to fix what was broken, and an assessment
of the fix performance. If the "fix" is not included in the de-listing
criteria, then we have no assurance that the problem will not recur. Therefore,
the score keeping system for monitoring progress must include an assessment
of management actions being taken and of the effect they are having on the
target population. This will require that the score keeping incorporate population
dynamics and the factors influencing it through each stage of life. This
is
best expressed in the form of a life-cycle model that is linked to effects
of the 4 H's (habitat, harvest, hatcheries, and hydro) that people can manage.
We describe a framework for data gathering, analysis, monitoring, and adaptive
management that can be used to estimate probability that an ESU will persist
into the future. We present examples from West Coast populations of salmonids
to demonstrate how density-dependent survival operates in freshwater, how
survival
and carrying capacity can be linked to habitat features, how the probabilities
of environmental catastrophes can be estimated, and how adaptive management
can alter probabilities of population persistence during the implementation
of recovery plans. We also review the spatial and temporal variability in
populations and the environment, and describe how that variation can be accounted
for in
estimating persistence of an ESU.