Transcript PowerPoint - South Bay Salt Pond Restoration Project

South Bay Salt Pond Restoration-Challenges to Ecological Restoration
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
Goals of the Restoration Project
Restore and enhance a mix of
wetland habitats
Provide for flood management
Provide for public access and
recreational opportunities
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
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
San
Francisco
Bay
Habitats
ca. 1800
(SFEI EcoAtlas Project)
Our Urbanized Estuary
Oakland Harbor
Carquinez Straights
Conversion to Salt Ponds
90
80
70
Acres (x1000)
60
50
40
30
20
10
0
Past
Present
Future
Other
0
3
3
Bay Fill
0
13
13
Agriculture
0
1
0
Diked Wetland
0
7
4
Salt Pond
1
30
10
Tidal Marsh
57
7
31
Tidal Flat
21
14
14
A Mix of Habitats…
…for a Diversity of Species
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?
Three Conceptual Models
Tidal Salt Marsh
Constraints
*Low Levee Heights
*Uncertainties
*Poor Sediment Supply
Landscape Initial
Conditions
*Sediment Loads
*Slough/mudflat dynamics
Restoration
Actions
*Breaches
*Dredged Material
Managed Pond
Landscape Level—
bay, mudflats,
sloughs
Initial Pond Conditions
*Salinity
*Bathymetry
*Species Present
Adaptive
Management
Driving Forces
*Initial Pond Conditions
*Tidal Exchange
*Sediment Load
*Water Quality
Pond/LS Impacts
*Hg Methylation
*Slough/mudflat Impacts
*Human Impacts
Target Conditions
*Tidal Exchange of 4-6ft
*Mudflat at MHW
*Native Plants Dominate
*Breeding Clapper Rails
Vegetated Tidal
Marsh Conceptual
Model Flowchart
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
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)
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
Tidal Marsh Restoration:
Actions, Conditions, Constraints
Collect
Data
Collect
Data
Restoration
Actions
Adaptive
Management
Current
Conditions
Short-term
Conditions
Sediment Loads
Pond Elevations
Invasive Species
Pollutant Effects
Long-term
Conditions
Sea-level Rise
Landscape Change
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
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
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
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?
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?
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
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?
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
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