NYC Tidal Wetland Vulnerability Assessment

Christopher Haight1,3, Rebecca Swadek1, Ellen Kracauer Hartig1, 2, Rebecca Boger2, and Marit Larson1 1New York City Department of Parks & Recreation 2Brooklyn College, City University of New York (CUNY) 3Natural Areas Conservancy Multi-tier Assessment of NYC Salt Marshes

Tier 1: Desktop Analysis Tier 3: Marsh-wide Ecological Trends Analysis Assessments SLAMM

Tier 2: MidTRAM Tier 4: SSIM: Long-Term Monitoring Stations

NYCDPR Assessing Urban Salt Marshes 2 Developing a Vulnerability Index Goal: To synthesize data from landscape and field assessments with additional metrics (e.g., water quality data, etc.) in order to identify salt marsh complexes of the City that are in need of management and conservation Preserve Conserve Monitor x x x Manage Restore x x Protect x Value x x Less Immediate Action x Lower Priority x x x x x x

Threat / Vulnerability Tidal Marsh Complexes for Assessment

WETLAND COMPLEX ID # BRONX Pelham Bay Hutchinson River Outer BQ1.1 Pelham Bay Hutchinson River Inner BQ1.2 Pelham Bay Cove BQ2 Pelham Bay Turtle Cove outer BQ3 Westchester Creek BQ4 Pugsley Creek BQ5 QUEENS Udall’s Cove BQ6 Alley Creek Outer BQ7.1 Alley Creek Inner BQ7.2 Idlewild Park Outer JB 1.1 Idlewild Park Inner JB 1.2 BROOKLYN Spring Creek JB 2 Fresh Creek JB 3 Four Sparrow JB 4 STATEN ISLAND Arlington Marsh SI1 Saw Mill Creek Outer SI2.1 Saw Mill Creek Inner SI2.2 Neck Creek Outer SI3.1 Neck Creek Inner SI3.2 William T Davis Outer SI4.1 William T Davis Inner SI4.2 Richmond Creek SI5 Fresh Kills SI6 Lemon Creek Outer SI7.1 Lemon Creek Inner SI7.2

4 Assess recent salt marsh loss trends • Salt marsh boundaries in 1974 based on NYSDEC aerial photo mapping

• Salt marsh in 2012 based on field assessments and aerial photos

• Overlay to calculate areas of marsh loss along the waters edge from 1974 to 2012

1974 2012 Union Example from Idlewild Park, Queens, NY Net Marsh Loss on the Waterward Edge

Net Percent Waterward Marsh Net Waterward Marsh Loss Loss (acres/1974 area) (acres) 0% 10% 20% 30% 40% 50% 60% 0.0 5.0 10.0 15.0 20.0 Hutchinson Outer Hutchinson Outer Hutchinson Inner Hutchinson Inner Pelham Bay Cove Pelham Bay Cove Pelham Turtle Cove Pelham Turtle Cove Westchester Creek Westchester Creek Pugsley Creek Pugsley Creek Alley Creek Outer Alley Creek Outer Alley Creek Inner Alley Creek Inner Idlewild Outer Idlewild Outer Idlewild Inner Idlewild Inner Four Sparrow Four Sparrow Spring Creek Spring Creek Fresh Creek Fresh Creek Arlington Marsh Arlington Marsh Saw Mill Creek Outer Saw Mill Creek Outer Saw Mill Creek Inner 1 Saw Mill Creek Inner 1 Saw Mill Creek Inner 2 Saw Mill Creek Inner 2

Average Average

• Complexes with BOTH largest amount and largest percent waterward loss: Hutchinson River Outer, Alley Creek Outer, Spring Creek, and Pelham Turtle Cove (3 out of 4 in Long Island Sound)

Title of Presentation Goes Here 7 Title of Presentation Goes Here 8 Title of Presentation Goes Here 9 Title of Presentation Goes Here 10 11 Tier 3: Marsh-Wide Ecological Assessments

• 25 Salt Marsh Complexes

• Fifty plots arrayed across each marsh complex

• Plots arrayed along random-start transects that created a haphazard grid across the marsh

• Plots were 5m*1m

• Percent Cover by species was collected in each plot

• Shear vane strength at 10cm depth was measured in 5 subplots in the root zones of Spartina patens and Spartina alterniflora

NYCDPR Assessing Urban Salt Marshes 12 Existing condition sampling: vegetation cover

90

80

70 Other 60 Native 50 Species Long 40 Spartina Island patens 30 Sound

20 Spartina 10 alterniflora Avg. Vegetation Cover Percent Vegetation Avg. 0 Long Island Sound Jamaica Bay Staten Island

Staten Jamaica Bay Island Existing condition sampling: shear vane strength

35 Spartina 30 patens

25 Spartina alterniflora 20 Long

15 Island Sound

Vane Strength Vane 10

5

0 Long Island Sound Jamaica Bay Staten Island

Staten Jamaica Bay Island Restoration Opportunities Mapping

• Concerns Identified in the Field

• Concerns locations are recorded on GPS

• Polygons drawn from field points

Udall’s Cove, Queens 15 Conditions Index Development

50 40 30 • Examine data visually to reveal 20 trends 10 SPAL Cover

0 • Determine ecological significance of parameters

“ ” • Assign as indicators of good or High SPAL = “Bad” Condition “ ” bad condition in respect to Low SPAL = “Good” Condition vulnerability to sea level rise and marsh loss/impact “ ” • Rank top three worst and Marsh MarshID # of "Worsts“ “best” for each ecologically Pugsley Creek BQ5 6 important parameter and tally Udalls Cove BQ6 0 Alley Outer BQ7.1 4 across parameters to get ranking Alley Inner BQ7.2 3 Idlewild Outer JB1.1 18 Idlewild Inner JB1.2 16 16 Spring Creek JB2 12 GOOD Condition BAD Condition

HIGH Vane Strength LOW Vane Strength

HIGH Bearing Capacity LOW Bearing Capacity

HIGH Total Vegetation Cover LOW Total Vegetation Cover

LOW Unvegetated Cover HIGH Unvegetated Cover

LOW Hydrologic Feature Cover HIGH Hydrologic Feature Cover HIGH Phragmites australis Cover LOW Phragmites australis Cover

HIGH Iva frutescens and Baccharis LOW Iva frutescens and Baccharis halimifolia Cover halimifolia Cover

LOW Salicornia europaea Cover HIGH Salicornia europaea cover

LOW Spartina alterniflora Dominance HIGH Spartina alterniflora Dominance

LOW Shoreline loss (Trends) HIGH Shoreline loss (Trends)

LOW or No Subsidence HIGH Subsidence

HIGH Plant Species Richness LOW Plant Species Richness

LOW Number and Size of Ditches HIGH Number and Size of Ditches

LOW Area of Restoration Opportunities HIGH Area of Restoration Opportunities

17 Condition Index: Preliminary “Worst” Condition Complexes

20 * 18 * 16 14

conditions * 12 10 Worst" 8 6 4 2 Number of " 0

18 Condition Index: Preliminary “Best” Condition Complexes

8 * * 7 * * 6

5

4

3

2

1 Number of "Best" conditions 0

19 Next Steps

• Data to be added to index:

• Complete Trends Analysis data • Complete Restoration Opportunities data • SET data – subsidence and elevation change • SLAMM data – potential future loss • Include physical data – bathymetry, fetch, and wave data at sites

20 Next Steps • Use local data and index to help identify and recommend sites for pilot waterward marsh restoration projects

21 Thanks!

Contact: Chris Haight [email protected] 22