Geoscience Reference
In-Depth Information
to.increase.ecosystem.resilience.and.facilitate.ecosystem.adaptation.to.future.sea-
level.rises..The.“right”.strategy.depends,.in.part,.on.the.rate.and.magnitude.of.sea-
level.rise..Workshops,.attended.by.refuge.staff,.partners,.and.species.and.ecosystem.
experts,.were.held.to.review.the.problem,.revisit.management.objectives,.and.con-
sider.creative.solutions..The.scope.of.the.problem.was.deined.to.include.refuges.in.
the.northeastern.United.States.that.are.maintaining.dike.systems.that.support.coastal.
freshwater.impoundments.
The.fundamental.objective.is.to.effectively.and.eficiently.support.conservation.
targets. (as. deined. by. the. refuges'. Comprehensive. Conservation. Plans. or. Habitat.
Management.Plans);.means.objectives.include.supporting.target.species'.use.of.the.
impoundments. and. ecological. integrity.. These. objectives. will. be. translated. into.
attributes. (monitoring. metrics). that. represent. forage. quality,. level. of. disturbance,.
and.vegetative.cover.(target.species.use).and.desirable.ecological.processes,.an.index.
of.loristic.quality,.and.presence/absence.of.contaminants.(ecological.integrity)..The.
refuge.also.has.objectives.for.maintaining.visitor.safety.and.supporting.visitor.use.
and.education.that.are.related.to.the.issue.of.maintaining.the.dikes;.refuge.visitors.
enjoy.using.the.dikes.as.access.to.wetland.areas.for.bird.watching..These.objectives.
were.considered.constraints.for.the.purposes.of.this.problem.
Linked.decisions.are.involved.in.that.irst,.a.manager.needs.to.consider.a.large.
set.of.factors.that.affect.the.decision.to.maintain,.remove,.or.abandon.the.dike..For.
example,. the. status. of. the. freshwater. source,. annual. cost. of. dike. repairs,. public.
safety.considerations,.elevation.of.the.dike.and.the.projected.rate.of.sea.level.rise,.
presence. of. invasive. species. or. disease. agents,. and. stakeholder. concerns. are. all.
important.factors..Once.a.decision.has.been.made,.periodic.monitoring.of.speciic.
ecological.attributes.of.the.impoundment.(ecological.integrity).and.the.target.spe-
cies.using.the.impoundment.will.be.useful.in.informing.future.decisions..A.model.
is. under. development. that. will. support. the. initial. decision. to. remove,. repair,. or.
rebuild.the.dike.as.well.as.incorporate.the.monitoring.data.to.help.inform.future.
decisions.. The. decision. to. remove. the. dike. is. a. “one-time”. decision. (because. it.
is. unlikely. that. it. will. be. rebuilt);. the. decision. to. repair. or. rebuild. the. dike. can.
be. revisited. at. a. later. time.. By. working. together. and. sharing. their. monitoring.
information,. managers. can. learn. much. more. from. a. series. of. these. “one-time”.
decisions. made. in. different. places. than. any. individual. manager. could. learn. by.
monitoring.independently.
A. central. role. for. AM. is. reducing. the. uncertainty. associated. with. alternative.
management. actions. (Lyons. et. al.. 2008).. In. this. example,. uncertainty. about. the.
rate.of.sea-level.rise.is.a.major.issue,.but.the.outcomes.of.any.management.actions.
will.also.be.inluenced.by.drought.and.precipitation.patterns.(environmental.varia-
tion)..The.primary.uncertainties.are.the.outcomes.of.management.actions.that.are.
planned.(structural.uncertainty)..Few.coastal.freshwater.impoundments.have.been.
restored. to. saltmarsh. (dike. removed),. so. little. information. is. available. about. the.
outcomes. of. such. actions.. Management. alternatives. were. discussed. in. the. work-
shops.that.might.not.have.been.considered.by.a.single.manager.working.alone..For.
example,.relocating.an.impoundment,.if.the.beneits.outweigh.the.costs,.or.“moth-
balling”.the.impoundment.by.maintaining.the.dike.with.minimal.effort.while.more.
information.is.gathered.were.options.considered..Creating.ish.passage.around.or.
