Linking Coastal Wetland Monitoring and Restoration to Sediment ...
Linking Coastal Wetland Monitoring and Restoration to Sediment Management Danielle Kreeger, LeeAnn Haaf, Martha Maxwell-Doyle, Joshua Moody, Erin Reilly and Angela Padeletti
Coastal Wetlands Abundant Diverse Benefits: Flood Protection Water Quality Fish and Wildlife Natural Areas Carbon Capture See poster by Erin Relly
Coastal Marsh Declines Losing ~1 acre per day in the Delaware Estuary Losses due to various stressors
The Mid‐Atlantic Coastal Wetland Assessment Integrated monitoring of tidal wetlands for water quality, habitat management, and climate/restoration planning
Remote Sensing GroundTruthing Intensive Studies Station Monitoring
Two Decline Patterns Edge Erosion Horizontal
Interior Drowning Vertical
> 1 m per year edge loss
White = new open water Source: Riter and Kearney 2009
Edge Erosion vs. Accretion Majority of marshes are net eroding
Net Accretion
Net Erosion
Future Challenges Tipping Zone?
Most Salt Marshes Cannot Survive When SLR >1 cm per Year
Elevation Capitol Deficit
LeeAnn Haaf, PDE
Thin Layer Placement In theory, TLP buys time by boosting elevation capital temporarily See poster by LeeAnn Haaf
LeeAnn Haaf, PDE
Plant Growth Ranges
from Jim Morris
10 cm difference in elevation
Healthy Plants on Living Shoreline
See Moody talk, Tuesday 2:30 pm
Unhappy Plants on Nearby Living Shoreline
Plant Growth Ranges
Optimal Elevations
MSL
Mean Tidal Prism Vegetation Extent LeeAnn Haaf, PDE
Maintaining Elevation is Complicated
Primary Productivity
Nutrients
Sediment Supply
Elevation Capitol
Energy, Erosion
Sea Level
Slide from Don Cahoon, USGS 12
Sediments are a Critical Feature of the Delaware Estuary
Beneficial Use Why Needed?
Marshes need sediments More sediment is removed from the system by dredging than is replaced via river inputs Sediment deficits can lead to marsh drowning
Restoration and Beneficial Use BENEFICIAL USE CONFINED DISPOSAL FACILITY
Deposition Sediment in Runoff SALT MARSH Salt Marsh
ESTUARY
Erosion DEPOSITION
SHIPPING CHANNEL DK 15
Slide adapted from Burke 2010
Funding and Capacity are Limited
Living Shorelines
http://delawareestuary.org/science_programs_state_of_the_estuary_treb.asp
Considerations Myths Marshes are impaired if they have short stunted plants Marshes are impaired if they hold water Marshes would benefit from TLP if low in elevation
Facts • Short vegetation characterizes healthy high marshes • Pools, pannes, and creeks occur in healthy marshes • Hydrodynamics and tidal range can counter low elevation in some healthy marshes • Wetland impairment can stem from diverse causes • Sediment application (TL) can help or harm a marsh
Considerations Sediment deficits and TLP opportunities
can be safely identified using: • ecological reference datasets and • field assessments at candidate locations
Example: Marsh Futures Assessments
Lanscape > Local Restoration Planning 1. Regional Prioritization Regional Restoration Initiative 2. Remote Sensing Analyses, Models Coastal Resilience Tool Restoration Explorer Tool 3. On‐the‐Ground Assessment Marsh Futures Marsh Futures 3. On‐the‐Ground Analyses, Project Concepts 4. Project Concepts > Project Plans Installation/Implementation
5. Monitoring
6. Implementation
Installation/Implementation
Marsh Futures ‐ Field Physical – elevation, slope, erosion, substrate firmness Biological – blade height, light penetration Typical
Anomolous
Unhappy Plants on Nearby Living Shoreline
See also Collins poster See 2015 Summit talk by Kreeger 2017 Version of Marsh Futures under development
Marsh Futures Vulnerability Maps
Drowning Risk Elevation
Elevation Capital
Erosion Risk Shoreline Retreat Rates
What Tactics and Where? Oyster/Rock Breakwaters
Living Shorelines
Sediment Placement
Post Futures Guidance Maps Where will various tactics yield positive outcomes? What should be the sequence of interventions?
Demonstration Purposes Only
High Marsh Containment Thin-layer Enhancement Hybrid Living Shoreline Bio Living Shoreline
Additional Consideration Most marsh loss is at the edge and eroded sediments clog channels, therefore: • Consider TLP to restore lost marsh edges, in tandem with living shorelines • Stemming erosion of edges could decrease dredging frequency in nearby channels
24
Sediment Trapping by Living Shoreline
May 2010 Control
Treatment
June 2010
June 2011 25
What Next? Ideas • Map Dredging & BU Opportunities A GIS‐based project registry of planned sediment projects Identify tidal wetlands within vicinity
• Develop Decision Tree A systematic method to characterize site conditions
• Rapid Assessment at Candidate Sites Analyze site history and trajectory Field examination of physical & biological conditions, tailored to answer questions in decision tree
26
Decision Tree (examples) Is Marsh Impaired? Acreage loss over time
Yes
Is impairment at Edge or Platform?
Low condition score
Platform Tree
No Action
27
Edge Tree
Decision Tree – Edge (examples) Are Dredge Sediments Sand?
Yes
Can a Living Shoreline Be Built for Containment?
Yes
Are There Habitat Conflicts? No
No
No
Yes
No Action or Try Other Tactics
28
Proceed with Site Reconnaissance and Pre‐Permit Discussions
Decision Tree – Platform (examples) Is Elevation Below Plant Optimal Growth Ranges?
Yes
Would TLP Compact or Sink the Marsh?
Yes
Is Dredge Material Grain Size Appropriate? Yes
No
No
No
No Action or Try Other Tactics
29
Proceed with Site Reconnaissance and Pre‐Permit Discussions
Summary • Tidal wetlands are vital but are in decline • Projects are needed that address specific ecological impairments • Marsh Futures deduces site‐specific vulnerabilities using ecological datasets • Beneficial sediment use can help address certain types of impairment if matched to ecological needs; but there is risk of harm • Most tidal wetland decline is due to edge erosion, and restoration of degraded edges would help stem channel sedimentation 30
Thank You! Danielle Kreeger Science Director (302) 655-990, x104 │ DelawareEstuary.org Connecting people, science, and nature for a healthy Delaware River and Bay
31
Will Tidal Wetlands Keep Pace with SLR? Sediment Supply Primary Productivity
Nutrients
Energy, Erosion
Elevation Capitol
Sea Level
32
Tidal Marsh Condition PDE/BBP/DNREC: >400 points since 2010 (Mid‐TRAM) Condition Minimal Severe
Moderate
Coastal Wetlands Abundant Diverse Benefits: Flood Protection Water Quality Fish and Wildlife Natural Areas Carbon Capture See poster by Erin Relly
Coastal Marsh Declines Losing ~1 acre per day in the Delaware Estuary Losses due to various stressors
The Mid‐Atlantic Coastal Wetland Assessment Integrated monitoring of tidal wetlands for water quality, habitat management, and climate/restoration planning
Remote Sensing GroundTruthing Intensive Studies Station Monitoring
Two Decline Patterns Edge Erosion Horizontal
Interior Drowning Vertical
> 1 m per year edge loss
White = new open water Source: Riter and Kearney 2009
Edge Erosion vs. Accretion Majority of marshes are net eroding
Net Accretion
Net Erosion
Future Challenges Tipping Zone?
Most Salt Marshes Cannot Survive When SLR >1 cm per Year
Elevation Capitol Deficit
LeeAnn Haaf, PDE
Thin Layer Placement In theory, TLP buys time by boosting elevation capital temporarily See poster by LeeAnn Haaf
LeeAnn Haaf, PDE
Plant Growth Ranges
from Jim Morris
10 cm difference in elevation
Healthy Plants on Living Shoreline
See Moody talk, Tuesday 2:30 pm
Unhappy Plants on Nearby Living Shoreline
Plant Growth Ranges
Optimal Elevations
MSL
Mean Tidal Prism Vegetation Extent LeeAnn Haaf, PDE
Maintaining Elevation is Complicated
Primary Productivity
Nutrients
Sediment Supply
Elevation Capitol
Energy, Erosion
Sea Level
Slide from Don Cahoon, USGS 12
Sediments are a Critical Feature of the Delaware Estuary
Beneficial Use Why Needed?
Marshes need sediments More sediment is removed from the system by dredging than is replaced via river inputs Sediment deficits can lead to marsh drowning
Restoration and Beneficial Use BENEFICIAL USE CONFINED DISPOSAL FACILITY
Deposition Sediment in Runoff SALT MARSH Salt Marsh
ESTUARY
Erosion DEPOSITION
SHIPPING CHANNEL DK 15
Slide adapted from Burke 2010
Funding and Capacity are Limited
Living Shorelines
http://delawareestuary.org/science_programs_state_of_the_estuary_treb.asp
Considerations Myths Marshes are impaired if they have short stunted plants Marshes are impaired if they hold water Marshes would benefit from TLP if low in elevation
Facts • Short vegetation characterizes healthy high marshes • Pools, pannes, and creeks occur in healthy marshes • Hydrodynamics and tidal range can counter low elevation in some healthy marshes • Wetland impairment can stem from diverse causes • Sediment application (TL) can help or harm a marsh
Considerations Sediment deficits and TLP opportunities
can be safely identified using: • ecological reference datasets and • field assessments at candidate locations
Example: Marsh Futures Assessments
Lanscape > Local Restoration Planning 1. Regional Prioritization Regional Restoration Initiative 2. Remote Sensing Analyses, Models Coastal Resilience Tool Restoration Explorer Tool 3. On‐the‐Ground Assessment Marsh Futures Marsh Futures 3. On‐the‐Ground Analyses, Project Concepts 4. Project Concepts > Project Plans Installation/Implementation
5. Monitoring
6. Implementation
Installation/Implementation
Marsh Futures ‐ Field Physical – elevation, slope, erosion, substrate firmness Biological – blade height, light penetration Typical
Anomolous
Unhappy Plants on Nearby Living Shoreline
See also Collins poster See 2015 Summit talk by Kreeger 2017 Version of Marsh Futures under development
Marsh Futures Vulnerability Maps
Drowning Risk Elevation
Elevation Capital
Erosion Risk Shoreline Retreat Rates
What Tactics and Where? Oyster/Rock Breakwaters
Living Shorelines
Sediment Placement
Post Futures Guidance Maps Where will various tactics yield positive outcomes? What should be the sequence of interventions?
Demonstration Purposes Only
High Marsh Containment Thin-layer Enhancement Hybrid Living Shoreline Bio Living Shoreline
Additional Consideration Most marsh loss is at the edge and eroded sediments clog channels, therefore: • Consider TLP to restore lost marsh edges, in tandem with living shorelines • Stemming erosion of edges could decrease dredging frequency in nearby channels
24
Sediment Trapping by Living Shoreline
May 2010 Control
Treatment
June 2010
June 2011 25
What Next? Ideas • Map Dredging & BU Opportunities A GIS‐based project registry of planned sediment projects Identify tidal wetlands within vicinity
• Develop Decision Tree A systematic method to characterize site conditions
• Rapid Assessment at Candidate Sites Analyze site history and trajectory Field examination of physical & biological conditions, tailored to answer questions in decision tree
26
Decision Tree (examples) Is Marsh Impaired? Acreage loss over time
Yes
Is impairment at Edge or Platform?
Low condition score
Platform Tree
No Action
27
Edge Tree
Decision Tree – Edge (examples) Are Dredge Sediments Sand?
Yes
Can a Living Shoreline Be Built for Containment?
Yes
Are There Habitat Conflicts? No
No
No
Yes
No Action or Try Other Tactics
28
Proceed with Site Reconnaissance and Pre‐Permit Discussions
Decision Tree – Platform (examples) Is Elevation Below Plant Optimal Growth Ranges?
Yes
Would TLP Compact or Sink the Marsh?
Yes
Is Dredge Material Grain Size Appropriate? Yes
No
No
No
No Action or Try Other Tactics
29
Proceed with Site Reconnaissance and Pre‐Permit Discussions
Summary • Tidal wetlands are vital but are in decline • Projects are needed that address specific ecological impairments • Marsh Futures deduces site‐specific vulnerabilities using ecological datasets • Beneficial sediment use can help address certain types of impairment if matched to ecological needs; but there is risk of harm • Most tidal wetland decline is due to edge erosion, and restoration of degraded edges would help stem channel sedimentation 30
Thank You! Danielle Kreeger Science Director (302) 655-990, x104 │ DelawareEstuary.org Connecting people, science, and nature for a healthy Delaware River and Bay
31
Will Tidal Wetlands Keep Pace with SLR? Sediment Supply Primary Productivity
Nutrients
Energy, Erosion
Elevation Capitol
Sea Level
32
Tidal Marsh Condition PDE/BBP/DNREC: >400 points since 2010 (Mid‐TRAM) Condition Minimal Severe
Moderate
