Partnership for the Delaware Estuary

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Tidal Wetlands in the Delaware Estuary: Projected Effects of Salinity and Sea Level Rise and Potential Adaptation Strategies

Danielle Kreeger

Science Director Partnership for the Delaware Estuary

Importance of Tidal Wetlands

Tidal Wetlands A Signature Trait of System •Near Contiguous Band

•Diverse:

Freshwater Tidal Marshes Brackish Marshes Salt Marshes

Tidal Wetlands A Signature Trait Ecological Values: Structural habitat for fish and wildlife nurseries for imperiled taxa Functional food web water quality flood protection

+ Many other supporting services

Wetland Ecosystem Services Milenium Ecosystem Assessment 1º Service

2º Service Food

Provisioning

Genetic Materials Biochemical Products Fiber and Fuel Sequestration

Carbon

Storm Protection/ Wave Attenuation/ Flood Protection Gas Regulation

Cultural/ Spiritual Human Well Being

Supporting

Erosion control Protect Property Values and infrastructure Carbon Sequestration Oxygen production

Water Quality

Sequestration, Filtering

Recreation Spiritual and Inspirational

Bird watching, hunting, boating Native American Uses University reasearch & school projects/trips Landscape pictures, paintings, open space Wildlife, shellfish, insects Maintain Plant Communities Primary Production

Educational Aesthetic Value Habitat Biodiversity Production Water Cycling/Hydrologic Regime Nutrient Cycling/Biogeochemical Processes

4º Service

Fisheries Support Algae and invertebrate production Phragmites control research Research in Antifungal Agents Cellulose stock

Sediment Stabilization

Regulating

3º Service

Maintain trophic cycles, soil building

Carbon Caps, mitigation Meet TMDLs for sediment

TMDLs: Nutrients, Pollutants

Valuation of New Jersey’s Natural Capital and Ecosystem Services New Jersey Department of Environmental Protection

Slide from Bill Mates, NJDEP

Kreeger

6

Tidal Wetlands A Signature Trait of the Delaware Estuary System Ecological Values: Structural

habitat for fish and wildlife nurseries for imperiled taxa

Functional

food web water quality flood protection

Concerns:

Degradation

Degradation

Severely Stressed 35%

Minimally or Not Stressed 17%

Moderately Stressed 48%

Tidal Wetlands Ecological Values: Structural

habitat

Functional

food web water quality flood protection

Concerns: Degradation

Conversion & Loss

Freshwater Tidal Wetland Acreage Estimated

< 5% remains

Tidal Wetlands

1992

Ecological Values: Structural

habitat

Functional

food web water quality flood protection

2006

Concerns: Degradation Conversion & Loss

Sea level rise Salinity rise

Canary Creek Marsh, DE

Shoreline Erosion

Courtesy D. Bushek, Rutgers

Courtesy J. Gebert, ACOE

Tidal Wetlands Ecological Values: Structural

habitat

Functional

food web water quality flood protection

Concerns: Degradation Conversion & Loss Sea Level Rise

Storms

Tidal Wetlands Concerns:

Degradation Conversion and Loss Sea Level Rise Storms

Sediment budget

Climate Change in the Delaware Estuary 1. Likely Physical Changes Temp

Salinity

Sea Level Rise

Storms

2. Example Effects on Resources

Drinking Water

Marshes

Bivalves DK 17

Climate Adaptation Planning

Case Studies

ID Vulnerabilities

Ecological Valuation

Tidal Marshes

Bivalve Shellfish

Adaptation Options

Recommendations and Reporting

Drinking Water Kreeger

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Tidal Wetland Vulnerability? Freshwater Tidal Marshes • Salinity Rise Causes Conversion to Brackish • Barriers to Landward Migration • Others: Tidal Range, Seasonal Drying/Wetting

Salt Marshes • Sea Level Rise, Subsidence and Sediment Deficits Lead to Drowning • Storms and Wind Wave Erosion • Barriers to Landward Migration • Others: Seasonal Wetting/Drying, Invasives

Tidal marshes need to move: 1) horizontally (landward) and/or 2) vertically (to keep pace)

Can they do it? Where? Slide adapted from Michael Craghan, Rutgers

Tidal Wetlands Adaptation Planning

Goal: Maximize long-term ecosystem health and resiliency

Wetland Tough Choices • Where will wetlands will be converted to open water? • Where can we save them ? • Where is strategic retreat the best option? DK 21

Projecting the Fate of Tidal Wetlands and Their Ecosystem Services Using SLAMM Modeling - Industrial Economics

2000

2100

Areas for Model Improvement • Erosion/Accretion Rates • Better Vegetation Classifications • Marsh Drowning Mechanisms

Added Complexity •Ecological Flows

•Land Use Change

•LNG Terminal

•Spills, NRDA

•Dredging •Withdrawals •Inundation, SLR •Horseshoe Crabs, Red Knots •Emerging Pollutants

So What Can We Do?

What Can We Do? 1. Preserve Resiliency Protect and Conserve (CCMP)

What Can We Do? 2. Monitor & Study

MACWA The Mid-Atlantic Coastal Wetland Assessment

What Can We Do? 3. Maintain, Enhance, Restore.. Shovel Ready Projects !!

…But Smartly Regional Restoration for Future Sustainability /

Changes in Wetland Function Natural versus Restored Reference Wetland Condition

Function

Existing Wetlands

Restored Wetlands

time

Slide from Amy Jacobs (DE DNREC)

Principle: “Restore” for the Future • Forecast future sustainable states • Smart “restoration” = climate adaptation



Shift policy and management paradigms

DK 31

Delaware Estuary Living Shoreline Initiative Shellfish as Natural Breakwaters

• • • •

Reduce wave energy Trap silt Reduce bank erosion Protect salt marsh Slide from Dave Bushek, Rutgers

Salt Marshes

Geukensia demissa

Ecosystem Engineers

Kathy Klein

Mussel – Spartina Mutualism

Ribbed mussels as an alternative target restoration species – Not commercially important, not eaten – No conflict between restoring shellfish and protecting human health and industry

– Mussels provide ecological benefits like oysters – Filtration, habitat enrichment – Biodeposition facilitates cord grass production and levee formation – Shoreline stabilization

– Could combine with restoration of marshes and nearshore oyster reefs for greater impact, in some areas

Living Shorelines

Importance of Shellfish to Examples the Delaware Estuary Watershed

Site D - Lower Energy

Log + Log + Shell Bags

Goal: Maximize Future Tidal Wetland Natural Capital Principles: 1. Base natural capital on functional acreage, not just acreage enhancing condition of existing wetlands may yield greater functional acreage in the long term compared to traditional restoration/creation (acreage focus)

2. Strive for high resilience and low vulnerability invest in wetlands that are most sustainable 3. Consider Ways to Mitigate Watershed Stressors broad impacts (sediment deficits, nutrient imbalances) may be best addressed with management and policy decision-making Kreeger

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Carbon Sequestration Uplift

vs

Preservation and Enhancement

How much CS per $ in 1 year? in 30 years?

(e.g. Living Shorelines)

condition Landward Migration Investments

Kreeger

function

Carbon Seq. Traditional Restoration, acreage Creation

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- End -

e.g., Carbon Sequestration Some Literature Temperate wetlands accumulate 1.42 tons C ha-1 yr-1 Wetlands represent the largest component of the terrestrial biological C pool Average soil organic carbon density (Denmark) Wetlands: 35.6 kg m−2 Forests: 16.9 kg m−2 Agricultural areas: 14.0 kg m−2 Conversion of agricultural lands to wetlands can enhance C sequestration In contrast to other wetlands, tidal salt marshes release negligible amounts of greenhouse gases and store more carbon per unit area