South Bay Salt Pond Restoration Challenges to Ecological Restoration

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South Bay Salt Pond Restoration-- Challenges to
Ecological Restoration
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Topics Covered in this Talk

• Goals of the Project Scientific Input
• Restore to What?
• Key Habitats in the Restoration Plan
• Constraints on Restoration Success
• Some Key Questions
• Moving forward in the face of
• Uncertainty

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Goals of the Restoration Project

• Restore and enhance a mix of wetland habitats
• Provide for flood management
• Provide for public access and recreational
  opportunities

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Scientific Direction is Needed

• To identify ecologically meaningful restoration
  goals
• To identify and evaluate uncertainties,
  constraints and complications
• To identify ways to reach ecological restoration
  goals in light of these challenges

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Restore to What? What is the Goal?

• Native, indigenous ecosystem as a goal
• Improving ecological functioning as a goal
• Historical view helps guide restoration goals
• Current conditions guide restoration goals

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San Francisco BayHabitats ca. 1800 (SFEI
EcoAtlas Project)
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Our Urbanized Estuary

• Oakland Harbor

• Carquinez Straights

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Conversion to Salt Ponds
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(No Transcript)
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A Mix of Habitats
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for a Diversity of Species
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Habitat Mix

• Restore Vegetated Tidal Salt Marsh
• Manage Ponds of Various Salinities
• Maintain Ecological Functions of Mudflat and
  Slough Habitats outside Ponds
• How do we restore tidal salt marsh and manage
  salt ponds while maintaining the ecological
  support provided by habitats outside the ponds?

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Three Conceptual Models

• Tidal Salt Marsh
• Managed Pond
• Landscape Level
• bay, mudflats,
• sloughs

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Factors that Limit Full Ecological Restoration

• Scientific Constraints Data on sediment loads,
  sea-level rise
• Technical Constraints Engineering limitations
• Human Impacts Adjacent land uses, flooding,
  mosquitoes
• Regulatory Requirements Water quality, species
• Economic Constraints Costs of different actions

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Scientific Constraints

• Missing data on current conditions critical to
  restoration of the target habitat
• Lack of data on short-term ecological processes
  (acting immediately after restoration actions
  initiated)
• Inability to predict long-term ecological
  processes (acting long after restoration is
  initiated)

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Goals of Restoration Science

• Identify the conditions and processes most
  important to successful restoration
• Collect data on essential conditions
• and processes, where possible
• Estimate range of uncertainty
• produced by not having
• all necessary data

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Sediment Loads Invasive Species
Sea-level Rise Pond Elevations Pollutant
Effects Landscape Change
Tidal Marsh Restoration Actions, Conditions,
Constraints
Collect Data
Collect Data
Adaptive Management
Restoration Actions
Current Conditions
Short-term Conditions
Long-term Conditions
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Potential Constraints on Successful Salt Marsh
Restoration

• Levee heights/adjacent land uses
• Inadequate sediment supplies
• Sea-level rise
• Non-native invasive species
• Pollutant impacts
• Importance of particular ponds

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Potential Constraints on Pond Management

• Ability to maintain salinities at suitable levels
  for target species
• Ability to maintain levees and structures
• Smell associated with algal decay
• Importance of particular ponds for tidal marsh
  restoration

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Potential Impacts of Restoration on South Bay
Waters, Mudflats, Sloughs

• Localized salinity changes due to pond water
  release
• Regional loss of mudflat due to sediment sinks in
  ponds being restored to salt marsh
• Local loss of slough habitat from scour due to
  changes in water circulation

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Some Key Questions

• Sediments
• To what extent is the suspended sediment supply
  adequate for restoration?
• How might sediment needs of
• restoring pond affect sloughs
• and mudflats in the Bay?

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Some Key Questions

• Non-native Species
• Can we prevent non-native,
• species, esp. Spartina
• alterniflora and predators,
• from dominating restored
• marshes?
• What ecological effects are
• likely from particular non-native species?
• Are there design alternatives, e.g., levee
  design, breach location, etc., that can be
  incorporated to prevent the access of non-native
  species into restored wetlands?

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Some Key Questions

• Habitats and Species
• What ecosystem functions are
• provided by the existing habitats
• and habitats planned for
• restoration?
• Can remaining ponds be
• managed to increase their
• shorebird and waterfowl
• carrying capacity?
• What physical factors drive the conversion of one
  habitat type to another? Are there any critical
  factors that may limit ecosystem development

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Some Key Questions

• Pollutants
• To what extent might restoration activities
  release contaminants, especially mercury?
• What are the ecological effects of released
  contaminants?
• What is the potential for nuisance algal blooms
  in future managed ponds?

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Dealing with Uncertainty

• Analyze existing data
• Collect additional data in the short-term
• Model ecological processes
• Assess uncertainty (modeling, stats)
• Conduct long-term monitoring
• Conduct new research

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Moving Forward with Restoration

• Use the best existing data
• Collect more data during planning
• Implement the most scientifically-sound plan
• Use adaptive management to learn improve