South Bay Salt Pond Restoration-The Chance of a Lifetime!
Topics Covered in this Talk
• Charge of the Science Team
• What is Restoration?
• Past and Current Habitats
• Major Ecological Communities
• The Science Strategy
• Some Key Questions
• Developing Our Knowledge Base
Charge of the Science Team
• Provide scientific direction for restoration planning,
implementation and monitoring
• Bring science into all phases of the process and to all involved
parties
• Develop a science strategy and conceptual models to guide the
restoration of South Bay ecosystems
• Identify critical data needs
• Identify uncertainties
• Help guide consultant activities and review products
Having a Science Team…
• Is unique and proactive.
• Will help to assure that science is included
at every phase of the project.
• Is essential for a successful program.
Interdisciplinary Practice of
Environmental Restoration
Jackson, et al. (1995):
Ecological restoration is the process of repairing damage
caused by humans to the diversity and dynamics of
indigenous ecosystems.
•
•
•
•
•
Science
Technology
Regulation/Policy
Economics
Public Interaction
Restoration as Project
and as Experiment
Planning = Hypothesis
Implementation = Run the experiment
Monitoring = Collect/analyze data
Adaptive Management
• Using data collected during monitoring to
improve restoration projects
• Apply to the current project to better
achieve restoration goals
• Use to improve the design of future projects
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
South Bay: Then and Now
90
80
70
Acreage (x1000)
60
50
40
30
20
10
0
Past
Present
Other
0
3
Bay Fill
0
13
Agriculture
0
1
Diked Wetland
0
7
Salt Pond
1
30
Tidal Marsh
57
7
Tidal Flat
21
14
What are Tidal Salt Marshes?
• Inundated by tides twice a day
• Have water-logged, anaerobic soils
• Dominated by wetland, halophilic plant species:
– Cordgrass (Spartina foliosa)
– Pickleweed (Salicornia virginica)
Cordgrass and Pickleweed
Mature Plant Community Zonation
• Low marsh: cordgrass
• Mid-marsh: pickleweed
• High marsh: saltgrass (Distichlis spicata), alkali
heath (Frankenia salina), Gumplant (Grindellia
humilis)
• Upland transition: saltgrass, alkali heath, coyote
bush (Baccharis pilularis), Atriplex spp.
Tidal Marsh Zonation
regularly inundated
rarely inundated
high accretion rates
low accretion rates
low marsh
Spartina foliosa
mid-marsh plain
Salicornia virginica
high marsh upland transition
Salicornia virginica
Frankenia salina
Distichlis spicata
Ecological Succession:
Ecosystem Development
• A salt marsh is formed when an area goes from a
disturbed or former salt marsh site from to the mature
community
• Natural restoration is called ecological succession—the
process we want to mimic
• Salt marsh successional phases:
– Open water
– Mudflat
– Vegetated mudflat
Tidal Salt Marsh Restoration Begins with
Open Water…
… and the tides bringing in sediment,
organisms and seeds.
Next, Mudflats form…
…stabilizing at an equilibrium point.
Then, Vegetation Colonizes
But, This is Not the End of the Process.
As the marsh matures…
• Nutrients build up
• Species composition changes
• A mosaic of habitat types develops
Marsh Restoration Takes Time
• Time to reach marsh plain ~5-20 yrs
• Time for dominant plants ~10-35 yrs
• Maximum nutrient loads and full
ecosystem functioning ~50-100 yrs
This Program will Take Time
• Projects will be implemented in phases
– Collect data on progress
– Apply to next phases
– Collect funding for phases
• Natural processes take time
Salt Ponds as a Major South Bay
Wetland Habitat
• Historically, existed in low acreage
• Extensively developed from late 1800s to
1940s
• Are wetland habitats with their own ecology
Those Crazy Salt Pond Colors
What causes those colors?
It’s the microorganisms!
• Low to mid-salinity: Green algae dominate
• Salinities increase: The algae, Dunaliella,
lends a lighter green color
• Mid- to High Salinity: Dunaliella produces
a red pigment
• Very High Salinities: Brine shrimp (Artemia
franciscana) provide orange colors and
Stichococcus (a bacteria) adds red hues
Many species use these ponds
Avian Biodiversity and Abundance
• 34 shorebird species—1 million birds
• 35 waterfowl species—250,000 birds
• At least 36 species of “other birds” closely associated
with San Francisco Bay habitats
• At least 9 state- and federally-listed threatened or
endangered species
Bird Species: Continental Population
Trends
• In General: Wetland-dependent bird
populations are far below historic levels.
• Shorebirds: 16 of 47 U.S. species declined
over the last 25 years
• Waterfowl: Steep declines in some species,
such as pintail and canvasbacks
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
One thing is clear…
we cannot go back to the 1800s
• Must consider importance of habitat changes
– Salt ponds provide habitat
– Urban conversion is difficult to reverse
• Must consider existing adjacent land uses
– Impacts on the restoration (pollutant runoff)
– Restoration impacts on the adjacent land (flood
prevention)
What is a Science Strategy?
• Provides a scientific framework
– Conceptual Models—landscape and pondlevel
– Key Questions and Data Needs
– Modeling Needs
• Provides scientific input at all stages of
the planning process
Why is this project so complex?
•
•
•
•
•
•
•
Adjacent land uses
Flood protection
Agency requirements
Pond subsidence
Water quality
Species diversity protection
Sedimentation rates and patterns
Some Key Questions
• To what extent is the suspended sediment supply
adequate for restoration?
• Can we prevent non-native, invasive species from
dominating restored marshes?
• To what extent might restoration activities release
contaminants? What are the ecological effects of
released contaminants?
• What effects will South Bay restoration have on largescale ecological features and processes?
More Key Questions
• How will the conversion of salt ponds to salt ponds and other
habitats affect shorebird and waterfowl numbers?
• Can remaining ponds be managed to increase their
shorebird and waterfowl carrying capacity?
• What are the predictions for sea-level rise and how will that
affect restored South Bay marshes?
Developing a Common
Base of Understanding
• Science Team and other experts meet with
Work Groups to share ideas
• Opportunities for public involvement in
research, monitoring and data collection
• Stakeholders give input to the Science Team
How might this project effect you?
•
•
•
•
•
Flood protection is a central goal
Public access is also a project issue
Changes in species communities
Healthier South Bay ecosystem
Improved water quality
Next Science Team Presentation:
• Restoration Constraints
• Scientific Uncertainties
• Complicating Factors