NYC Parks Powerpoint Template

NYC Tidal Marsh Assessment: Condition, Vulnerability and Restoration Opportunities

Christopher Haight1, Marit Larson1, Rebecca Swadek1, Ellen K. Hartig1, Nicole Maher2, Stephen Lloyd2, Lauren Alleman2, and Helen M. Forgione3

NYC Parks - Natural Resources Group 1 The Nature Conservancy2 Natural Areas Conservancy 3

NCER April 20, 2016 Why Urban Coastal Wetlands

• Coastal wetlands are a critical part of a livable NYC o resilient Park assets o aesthetic, recreational and educational value o ecosystem services (fisheries, bird communities, water quality) • Coastal wetlands are at risk • Planning, management and restoration can help protect our wetland assets for the future Historic NYC Wetland Extent Current NYC Tidal Wetlands Project Goals

• Assess current marsh condition

• Evaluate vulnerability (SLR)

• Identify opportunities for protection, conservation & restoration

Prioritize restoration & protection opportunities Ecological Assessment at 25 salt marshes

Desktop Analysis o Historic Loss Long Analysis Island Sound o SLAMM Rapid Ecological Assessments

o MidTRAM Marsh-wide Jamaica o Bay assessments Staten Island Identify key ecological attributes of marsh condition for which there are measurable indicator variables:

Marsh area % Development in buffer Species richness Total cover Low marsh soil strength Breeding bird count Bare soil cover Pool expansion Ditch density

Identify key measurable indicators of vulnerability available from SLAMM outputs, field and desktop assessments Percent high marsh Marsh area Edge density Waterward loss Potential gain from migration Potential loss by SLR

Idlewild Park, Queens, NY Salt marsh

Recently lost salt marsh Sea Level Affecting Marshes Model (SLAMM)

Likelihood of Coastal Marsh 2080s Idlewild Park

Example – Saw Mill Creek Marsh, Staten Island Condition Marsh Area

Native Species Richness

Low Marsh Soil Strength

Bare Peat Coverage

Ditch Density

-2 -1 0 1 2 3 Z-Score

Vulnerability

Marsh Area Potential Marsh Loss to SLR Potential Gain from Migration Trend in Waterward Marsh Loss Edge Density Percent High Marsh Total Score

-5 -4 -3 -2 -1 0 1 2 Z-Score Marsh Condition vs. Vulnerability

Higher condition/Lower Vulnerability 0.8 Higher condition/Higher Vulnerability

W. T. Davis Outer

Alley0.6 Creek Inner Four Sparrow Pelham Bay Cove

Richmond Creek 0.4 Saw Mill Creek InnerSaw Mill Creek Outer Hutchinson Inner 0.2 Turtle Cove Neck Creek Inner

Udall's Cove Marsh Neck Creek Outer 0 Alley Creek Outer -1.5 -1 -0.5 0 0.5 1 1.5 2 Hutchinson Outer W. T. Davis Inner Lemon Creek Inner Idlewild Marsh Inner -0.2 Fresh Kills Marsh Fresh Creek Marsh

Arlington Marsh -0.4 Spring Creek Bronx/QueensLong Island Sound Westchester Creek Jamaica Bay -0.6 Pugsley Creek Marsh Idlewild Marsh Outer

Staten Island -0.8 Lemon Creek Outer

Lower condition/Lower Vulnerability Lower condition/Higher Vulnerability -1 Marsh Area and Shape Explain Trends in Condition and Vulnerability Variables

R2 = R2 = -0.89 0.70 Identify and prioritize strategies for restoration

Short/Mid-Term: Increase viability of existing marsh sites  Remove fill and re-establish hydrology  Remove debris and revegetate • Increase elevation of drowning marsh surface • Restore shore edge of marsh where eroded

Long Term: Assure sustainability of marsh ecosystems • Secure adjacent parcels where marsh can migrate • Remove hard surfaces that impede marsh migration Opportunities for Restoration / Conservation

Actions Threats Targets

Acquisition/Transfe r Obstacles to Marsh Migration Long Term Restore Flooded Viability & Developed lands Function Reduced Capacity of NYC Elevation for Vertical Growth Saltmarsh Enhancement es in Rebuild Marsh Erosion and Study Area Edge Decreased Size Acquisition/ Transfer

Ownership across 25 NYC Marsh complexes

63 ac 36 ac

838 ac

Current Marsh Future Marsh with SLR Future new marsh acres in Study Area

60 Private

50 City/State/Federal

40 NYC Parks

Acres 30

0 Acquisition of advancement zones Restore Flooded Developed lands

Action prioritized by area of opportunity Elevation Enhancement

Action prioritized by % low marsh and future marsh loss in SLAMM Rebuild Marsh Edge

Action prioritized by acres, width and % of recent marsh lost and future marsh loss in SLAMM Are these a better long- term investment?

Is there anything we can do to save marshes that are highly vulnerable to begin with? Watershed / Water-body Considerations

1 0.8 0.6 0.4 JB LIS SI 0.2 0 -0.2 -0.4 -0.6 -0.8 -1

BQ JB SI Focus on watershed – specific needs

• SI = Acquire and transfer parcels

• JB = Restore elevation

• LIS = Address Edge Extension uncertainty Next Steps • Preserve existing marsh ecosystems and marsh migration zones for future – explore acquisition and easement strategies

• Prioritize high condition / low vulnerability marshes through best management practices and these 4 conservation strategies as needed o Address uncertainty - study shoreline retreat, sediment supply, and wave energy o Consider size and shape - conserve and restore to reduce fragmentation for long term health and viability

• Consider socio-economic or ecosystem services when pursuing opportunities for low condition / high vulnerability marshes

• Consider a watershed approach to conserving wetlands in addition to site by site restoration projects.

Appropriate strategy depends on goals, landscape context, time horizon, and socioeconomic factors NYC Parks - Natural Resources Group Christopher Haight Marit Larson Rebecca Swadek Ellen K. Hartig

Natural Areas Conservancy Helen M. Forgione

The Nature Conservancy Funding from U.S. EPA Region 2, Nicole Maher Wetlands Protection Program Stephen Lloyd Development Grant Lauren Alleman Kathleen Drake