Photo: R. Hancock

Sea Levels Affecting Marshes Model Using SLAMM to Conserve

Rhode Island’s Coastal Wetlands

Municipal Training Workshops October 28 & 30, 2014

James Boyd, CRMC Coastal Policy Analyst

Aesthetic Value of Salt Marshes

Painting: Charles Gordon Harris (1891-1963)

Why is Tidal (Salt) Marsh Important?

Forage and nursery habitat Nesting and migratory sites

Carbon sink

• $6,471/acre for maintaining fisheries (US East Coast; Barbier et al. 2011) • $81 million in RI commercial fishery landings (NOAA 2012)

• $208 million in RI recreational fishery value (NOAA 2012)

Clean water: nutrient (nitrogen) and pollutant uptake

$780-$15,000 per acre for water purification (Barbier et al., 2011)

Why is Tidal (Salt) Marsh Important?

Reduce Storm damage $2,931/acre/year

Costanza et al, 2008

$5 Billion of RI property protected by coastal habitats by 2100

Arkema et al., 2013

Why is Tidal (Salt) Marsh Important?

Rhode Island has lost 53% of its historic salt marshes over the last two centuries* due to man-made alterations (ditching and filling) resulting in a loss of about 4000 acres statewide

* Bromberg and Bertness, 2005

2010

2004

STB’s 10 years of restoration monitoring has shown that conditions can change rapidly in tidally restricted marshes

Recently, similar degraded conditions have been observed in marshes with no tidal restrictions

2010 Source: Save The Bay

May 15, 2014 Photo: J. Boyd August 13, 2014 Photo: J. Boyd

Source: http://tidesandcurrents.noaa.gov/inundation/

1.9-5.4 inches

> 1 foot above MHHW 230+ times

Sea levels are rising 1 inch every 10 years based on historic trend

http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8452660

Sea Level Continues to Rise

Increasing Frequency of Nuisance Flooding

http://tidesandcurrents.noaa.gov/publications/NOAA_Technical_Report_NOS_COOPS_073.pdf

Sea Level is Rising Faster along the Northeast US Coast

Figure 1 from “Hotspot of accelerated sea-level rise on the Atlantic coast of North America” Asbury Sallenger et al., 2012 Nature Climate Change doi:10.1038/NCLIMATE1597

Since about 1990, sea-level rise along the 600-mile stretch of coastal zone from Cape Hatteras, NC to north of Boston, MA have increased three to four times faster than the global average. Likely 8 to 11+ inches above global average SLR by 2100.

Glass and Pilkey, 2013. Earth Vol. 58, No. 5

1ft

3 ft

5 ft

Model Consensus of Future SLR Projections

USACE and NOAA SLR Curves

http://corpsclimate.us/ccaceslcurves.cfm

Source: Maine SeaGrant

Marsh Migration

Marsh Migration

Source: W. Ferguson, Save The Bay

Marsh Migration

Source: J. Boyd 05/15/14

Sea Level Affecting Marshes Model (SLAMM)

Simulates the dominant processes involved in wetland conversions during long term

sea level rise

Applied and improved since 1985

Used throughout the world

http://www.warrenpinnacle.com/prof/SLAMM/

Sea Level Affecting Marshes Model (SLAMM) North Kingstown Pilot Project (2011)

http://seagrant.gso.uri.edu/climate/habitat.html

All 21 Coastal Communities Completed

Region 1

Region 2

Region 3

SLAMM Project Goals 1. Develop marsh migration modeling results (maps) 2. Identify existing vulnerable wetlands 3. Identify affected upland parcels – opportunities and

challenges 4. Develop new CRMC coastal program adaptive

strategies, policies and standards (Beach SAMP) 5. Increase local capacity to proactively incorporate

sea level rise for wetlands (e.g., comprehensive plans, zoning overlays, conservation efforts, etc.)

SLAMM Predicted Statewide Salt Marsh Changes due to Sea Level Rise

SLR 1 Ft. 3 Ft. 5 Ft. Loss (Acres) 450 1895 3189

Gain (Acres) 1057 1148 2151

Net Change (Acres) 607 -747 -1038

50% of Current Salt Marshes

Photo: J. Boyd

Statistics for Coastal Wetland Loss with

5 feet Sea Level Rise

Town Coastal Wetland Loss (acres) Barrington 330.5 Bristol 99.2 Charlestown 321.9 Cranston 2.3 East Greenwich 0.4 East Providence 71.1 Jamestown 116.0 Little Compton 96.5 Middletown 42.6 Narragansett 354.0 New Shoreham 61.4 Newport 19.1 North Kingstown 148.6 Pawtucket 0.1 Portsmouth 357.6 Providence 3.1 South Kingstown 275.9 Tiverton 273.9 Warren 242.4 Warwick 195.9 Westerly 246.3 TOTAL 3,258.8

SLAMM maps on CRMC web page

http://www.crmc.ri.gov/maps/maps_slamm.html

Action 6.5.3 - Adopt Sea Level Affecting Marshes Model (SLAMM) data and projections as planning and decision-making support tool in statewide coastal wetland monitoring, protection and restoration strategy

RI Executive Climate Change Coordinating Council

http://www.planning.ri.gov/statewideplanning/climate/index.php

Municipal SLAMM Training Workshops

Recent Releases

http://seagrant.gso.uri.edu/projects-2/topics/community-resilience/

www.RIClimateChange.org

www.beachsamp.org

SLAMM Project is part of the Shoreline Change (Beach) SAMP

http://seagrant.gso.uri.edu/