The Delaware Estuary Living Shoreline Initiative (DELSI): Comparing Adaptive Management Practices at Two Treatments in the Maurice River, NJ Joshua Moody*, Dr. Danielle Kreeger, David Bushek, Angela Padeletti
DELSI: Delaware Estuary Living Shoreline Initiative Established in 2007 PDE and Rutgers HSRL Other Project‐Specific Partners
•Prototype for Matt’s Landing designs •First two sites where A double‐cusp was installed •Still experimenting with attachment techniques How logs are attached to each other How logs are secured with stakes •Experimenting with relative log positioning D1: overlapping logs D15: logs placed end to end
D1
D15
Matt’s Landing: E1 & E2
Matt’s Landing E1 & E2 : Adaptive Management 2010: E1 marsh: 13 logs (added second deck) E2 rip rap: 5 logs 2014: E1 marsh: 3 logs to stabilize new creeks E2 rip rap: 6 logs to add second deck 2015: E1 marsh: 4 logs lost to icing E2 rip rap: 5 logs lost to icing 2016: E1 marsh: no damage E2 rip rap: lost 2 logs, added shell bags Problem spot since 2014; new tactic
D15: Not Adaptively Managed •2009: 11 logs, 2 cusps •2010: Planting; material degradation begins
•2011: Lost cusp 1 (waterward) •2015: Revisited and surveyed
D15: 2015
Treatment
Control
D15: 2015
First Row Logs Gone
Second Row Logs Partially In Tact Mostly Degraded to Height of Shell bags
Are There Lessons to be Learned Regarding the Two Management Practices? 1. Does the adaptively managed living shoreline (E1) exhibit qualities indicative of a healthy marsh not present at the non‐adaptively managed living shoreline (D15)? 2. If there is a difference, can it be attributed to management interventions? *Same treatment types; possible differences in energy regimes
Relatively, How Have They Faired? Analysis Focused on E1 and D15 1. Q: Is marsh eroding behind living shoreline? Metric: Change in lateral shoreline position relative to control Method 1: Surveys: trimble total station 2010 & RTK‐GPS 2016 Collected along vegetated edge; ~1m spacing
Method 2: Analysis‐usgs DSAS
2. Q: Is the elevation appropriate for vegetation persistence? Metric: change in vertical position of marsh platform relative to control Method 1: Surveys: trimble total station 2010 & RTK‐GPS 2016 3 transects perpendicular to shoreline 4 elevation plots along each transect
Method 2: Analysis‐BACI model (2‐way ANOVA)
1
2
3
4
E1: Is Marsh Eroding? GIS Representation
E1: Is Marsh Eroding? USGS DSAS Analysis
•Treatment Moved Waterward
Control
•Control Moved Landward
Treatment
Net Movement (m)
Rate (m/yr)
Δ Area (m2)
Marsh Treatment
2.89 ± 1.88
0.47 ± 0.33
65.89
Marsh Control
‐0.61 ± 0.76
‐0.10 ± 0.13
‐21.85
E1: Is the Elevation Appropriate for Vegetation Persistence?
*
*
Impact Area (Plots 2 & 3): Elevation moved into the proper elevation range
E1 and D15 Comparison Checklist
E1
D15
Shoreline moved waterward at treatment
Shoreline moved waterward at treatment Created marsh at appropriate elevation for vegetation persistence
87.74m2 relative to no action
Created marsh at appropriate elevation for vegetation persistence
D15: Is Marsh Eroding? GIS Representation of Vegetated Edge
D15: Is Marsh Eroding? USGS DSAS Analysis
•Treatment Moved Waterward •Control Moved Landward
Net Movement (m)
Rate (m/yr)
Δ Area (m2)
D15 Treatment
3.71 ± 1.80
0.64 ± 0.27
90.65
D15 Control
‐3.19 ± 1.67
‐0.59 ± 0.22
‐82.97
D15: Is the Elevation Appropriate for Vegetation Persistence?
*
2009 2015
Plot landward of lost log was unable to build elevation
Plot landward of intact materials maintained its elevation
E1 and D15 Comparison Checklist
E1 Shoreline moved waterward at treatment
87.74m2 relative to no action
Created marsh at appropriate elevation for vegetation persistence
D15
Shoreline moved waterward at treatment 173.63m2 relative to no action
Created marsh at appropriate elevation for vegetation persistence 1. Material retained provide an energetic refuge 2. Vegetation moved down 3. Elevation vulnerability high 4. Vegetation line cusping 5. Likely trigger adaptive management tactic
Are There Lessons to be Learned Regarding the Two Management Practices? 1. Does the adaptively managed living shoreline (E1) exhibit qualities indicative of a healthy marsh not present at the non‐adaptively managed living shoreline (D15) –
Yes, proper elevation
2. If there is a difference, can it be attributed to management interventions? – Yes, by adding 2nd deck and amending deteriorating/lost materials – Facilitated by active goal‐based monitoring
Value Of Adaptive Management for Living Shorelines • Allows for augmentation to facilitate: – Horizontal position – Vertical position
• Provides data regarding: – Material vulnerabilities – Developmental trajectories • Physical • Biological
• Living shoreline is a measure of function – Functionality is dynamic – Monitoring/adaptive management helps us to understand variability in function over time and space
Questions? Joshua Moody Restoration Coordinator (302) 655-990, x115 │ DelawareEstuary.org Connecting people, science, and nature for a healthy Delaware River and Bay
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E1 and D15 • E1 and D15 Living Shorelines Moved Waterward While Controls Eroded • Only E1 Within Optimum Growth Range for Vegetation • Starting to see some landward cusping at D15 – Erosion or Drowning? – Monitoring Needed Δ Area (m2) Marsh Treatment