Tidal Wetlands at the Nexus of

Coastal Resilience, Carbon Markets, and Ecosystem

RestorationHeida L. Diefenderfer, Ph.D.

Energy and Environment Directorate

Coastal Sciences Division, Marine Sciences Laboratory

Sequim, WA

National Academies of Science, Engineering, Medicine

Government-University-Industry Roundtable 5 Feb 2020

PNNL-SA-151067

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Blue carbon is the

carbon stored in

marine and coastal

ecosystems.

What is Blue Carbon?

Mangroves in the

Florida Everglades

Herr and Landis 2016, Policy Brief,

Coastal blue carbon ecosystems,

IUCN and TNC

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Many Types of Tidal Wetlands WorldwideTidal freshwater marsh and forest with

Chinook salmon, Columbia RiverSalt Marsh on Delaware Bay and Salt

marsh sparrow

Low

mangrove,

Dominican

Republic

Mangroves in

Costa Rica, and

sea turtle

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Wetlands on Tidal River Floodplains

Tide’s Out: Environmental Sampling

at a Restored Marsh, Trestle Bay,

Columbia River Floodplain, Oregon

U.S. Tidal Rivers with extensive tidal wetland

development include the Columbia (shown),

Delaware, Hudson, and Cape Fear Rivers,

and tributaries of Chesapeake Bay

Borde et al., forthcoming, Ecosphere

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Focus on Science in Tidal Wetlands at the Nexus

Drivers &

OutcomesConservation Planning

Options• I. Wetland status and trends

• II. Wetland ecosystem services

• III. Blue carbon markets

• IV. Wetland stocks & markets example

• V. Ecological engineering

• VI. Science and technology challenges

Central Question:

Will tidal wetlands emerge as viable carbon offset markets that support ecological restoration

to increase infrastructure resilience and other ecosystem services on the coasts?

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• Historical: 87% of the global wetland

resource lost since the year 1700 CE

• Continuing: since 1970, 35% of total

natural wetlands lost globally

• Globally, blue carbon sinks lose

~0.7–7% of their area annually

• Data unavailable in many places

Global Trends in Natural Wetland Area still Down

Ramsar

Convention

on Wetlands

signed 1971

McLeod 2011, Frontiers in Ecology & the Environment;

Davidson 2014, Marine & Freshwater Research;

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• In West Coast estuaries, combined

DEMs and water level models (right)

show that about 85% of vegetated

tidal wetlands have been lost

• In Eastern coastal watersheds

59,000 acres/yr wetlands lost per

year 1998 – 2004

• Gulf: losing 1 football field every 90

minutes (down from 1 field every 60

minutes prior to marshland building)

Estimated Tidal Wetland Area Trends, U.S.A.

Brophy et al. 2019 PLoS One; Dahl and

Stedman 2013, NOAA-NMFS and USFWS Brophy et al. 2019 PLoS One

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Coastal wetlands are only ~15% of natural wetland area globally

….and deliver 20.4 trillion International Dollars (Int$)/year or 43% of

total global ecosystem services from all types of natural wetlands.

Ecosystem Services of Tidal Wetlands

Stedman and Dahl. 2008, NOAA-NMFS and USFWS; Davidson & Finlayson 2018; Davidson

et al. 2019; DOD bases: McDowell et al. 2019 (SERDP)

• Coastal economy: Fisheries

(finfish, shellfish), recreation

• Stabilize shorelines

• Buffer against storms, floods

• Filter, store, and detoxify water

• Maintain biodiversity

• Provide diverse habitats

• Highly productive

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Simplified Model of Carbon in Tidal Wetlands

Carbon dioxide and

Methane emissions

Carbon Dioxide uptake

Soil

Plants

Carbon Storage

Tidal wetland

Storing carbon in soils keeps it out of the

atmosphere, helping to mitigate climate change

Carbon-Transfer Food Web

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• Greater marsh continuity and marsh

vegetation roughness reduce storm

surge levels in Louisiana

• Economic analysis: modest increases

of 10% in wetland continuity plus 0.1%

in roughness would save 4-7 typical

residential properties for every 6 km of

coastal Louisiana in storms

Coastal Residential Communities Protected by Tidal Wetlands in the Temperate Zone

Atchafalaya River Delta, Coastal LouisianaBarbier et al. 2013, PLoS One

Building marshes in coastal Louisiana since the

Coastal Wetlands Planning, Protection and

Restoration Act of 1990 (Public Law 101-646).

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• 2004 Indian Ocean tsunami: villages

behind mangroves fared better

• 10,000 fewer people lost their lives

because mangroves reduced impacts

• NGOs successfully encouraged

villagers to replant and monitor

mangroves using debt forgiveness

incentives for new post-disaster small

business loans with economic effects

Coastal Residential Communities Protected by Tidal Wetlands in the Tropics

Danielsen 2005, Science; Pearce 2014, New Scientist

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Activities Offset through Voluntary Carbon Markets

1. U.S.: 1,218 KtCO2e

2. Netherlands: 1,081 KtCO2e

3. United Kingdom: 619 KtCO2e

4. France: 582 KtCO2e

Voluntary markets are a ”testing

ground” (Forest Trends 2017)

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Voluntary Carbon Offsets Purchased: Volume, Price & Total Value

Forest Trends Ecosystem Marketplace 2019

Natural systems carbon

markets now lead over

renewable energy.

264%

increase in

volume of

offsets

generated

through

Forestry and

Land Use

activities,

driven by

demand.

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• Two new greenhouse gas offset methods for

crediting blue carbon projects:

Verified Carbon Method (VM) 7 - Tidal

wetland and seagrass restoration

VM 33 - Tidal wetland and seagrass

conservation

Demonstration projects needed to

accelerate verification and adoption.

Potential Blue Carbon Markets:

• Existing regulatory market in California,

offsets can be used for compliance;

pathways for new protocols such as tidal

wetlands

Can Blue Carbon Markets Help Turn the Tide on Wetland Losses?

Seagrass at DOE-PNNL Marine

Sciences Lab, Sequim, Wash.

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• In 2016, the U.S. was the first country to include

blue carbon ecosystems in national greenhouse

gas accounting:

See annual Inventory of U.S. Greenhouse Gas

Emissions and Sinks (EPA 1990-)

• “Limited representation of Pacific Coast

information as compared with that for the Atlantic

and Gulf of Mexico coastlines…inadequate to

track changes”

• “Implementing long-term observations in Pacific

Coast estuaries is a priority”

Limited, Uneven Blue Carbon Data Availability

State of the Carbon Cycle Report, 2018

Joint research in natural science

and economics is needed.

Example:

National Estuarine Research

Reserve System Collaborative,

Pacific Northwest Blue Carbon

Working Group

Tideland spruce, Columbia River

BLUE CARBON

PROJECT TEAM

Craig Cornu

Institute for Applied

Ecology

Dr. Jude Apple

Padilla Bay NERR

Dr. Boone Kauffman

Oregon State

University

Dr. Chris Janousek

Oregon State

University

Amy Borde

Pacific Northwest

National Laboratory

Dr. Heida Diefenderfer

Pacific Northwest

National Laboratory

Dr. Ronald Thom

Pacific Northwest

National

Laboratory(Emeritus)

Dr. Steve Crooks

Silvestrum Climate

Associates LLC

Stefanie Simpson

Restore America’s

Estuaries

David Antonioli

Verified Carbon

Standard

STOCKS

Jeffrey Gaeckle

WA Dept of Natural

Resources

Evyan Sloane, J

Gerwein, M Bowen,

California Coastal

Conservancy

Dr. Jenny Liu

Portland State

University

Northwest Econ

Research Center

Sean Penrith

The Climate Trust

Sheida Sahandy,

Amber Moore

Puget Sound

Partnership

Shawn McMahon

Environmental

Services Inc

Lisamarie

Windham‐Myers

US Geological Survey

Laura Brophy

Institute for Applied

Ecology

Dr. Bree Yednock

South Slough NERR

Cathy Angell

Padilla Bay NERR

John Bragg

South Slough NERR

Pacific Northwest Coastal Blue Carbon Working GroupBlue Carbon Stocks Study

November 2016 to December 2019

Project funding provided by:Case Study: Collaborative PNW Carbon Stocks Assessment and Feasibility Planning for Blue Carbon Finance

Portion of a tidal wetland soil core

California

Oregon

Coos

Estuary

Yaquina

Estuary

Nehalem

Estuary

Lower

Columbia

Estuary

Washington

Padilla Bay

Skagit Bay

Gray’s Harbor

Snohomish Estuary

Humboldt

Estuary

ADDITIONAL MEMBERS OF BLUE

CARBON FINANCE TEAM

Scott Settelmyer

Terracarbon LLC

Steve Emmett-Mattox

Restore America’s Estuaries

Erin Swails

Terracarbon LLC

Lisa Beers

Silvestrum Climate Associates LLC

Kyler Sherry

The Climate Trust

Kirsten Feifel

WA Department of Natural Resources

Marisa de Belloy

Cool Effect

Stefanie Simpson

Restore America’s Estuaries

Amy Schmid

Verified Carbon Standard

Dr. John Rybczyk

Western Washington University

Katrina Poppe

Western Washington University

Blue Carbon Finance Study

September 2018 to December 2019

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• Most of the carbon sequestered in tidal wetlands is in the soil.

• Tidal wetlands remove and store ~10X more carbon per acre in the

soil than upland forests

How much Carbon is in tidal wetlands?

Pacific Northwest (PNW) data: Kauffman et al. in review Global Change Biology. Other data (left to right): Fourquerean et al. (2012). Nahlik

& Fennessy (2016; soil only). Kauffman et al. (2018). CONUS = mean ecosystem carbon stocks of USA tidal ecosystems (Holmquiest et al

2018). IPCC default IPCC (2014). Adame et al. (2013). Nahlik & Fennessy (2016). Kauffman et al (2020).

Green: Total

Aboveground

Carbon

Orange: Total

Belowground

Carbon

0

200

400

600

800

1000

1200

PNWseargrass

GlobalSeagrass

PNWHigh

marsh

PNW Lowmarsh

EstuarineEmergent

Brazilmarsh

CONUS IPCCdefault

Mexmarsh

Tidalforest

Estuarinewoody

Globalmangrove

Car

bo

n (

Mg

C/h

a)

TAGC

TBGC

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• Depositional ecosystems

• Tend toward balance with sea level

• Extreme example, at left:

Subduction-zone earthquakes off

Pacific Northwest coast. After rapid

tectonic subsidence (1964), rapid

accretion from sand flat to meadows

and thickets by 1973, and spruce by

1980. Why? Portage Bay is

macrotidal; a much slower process

in mesotidal systems of PNW

Why do Tidal Wetlands Sequester so much Carbon?

Atwater 1987 Science; Atwater et al. 2001 GSA Bulletin

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Systems Context of Tidal Wetlands: Pacific Coastal Temperate Rainforest Margin

Bidlack et al. In Review BioScience; Coastal Margins

NSF-RCN group in prep.

Ecosystem Context

Landscape Context

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Large-Scale Ecosystem Restoration

Diefenderfer et al., forthcoming, Frontiers in Ecology and the Environment

The U.S. spends billions of dollars on wetland restoration -- still

not enough to prevent habitat loss, species extinction, and the

release of carbon to the atmosphere and oceans.

Sacramento-San Joaquin Delta and

Suisun Marsh

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Resilience Planning Alternatives: Connectivity

• Do we restore tidal wetlands using

natural ecosystem processes like

sediment deposition?

• Reclaim more land from the ocean

or protect coastal communities with

new engineered infrastructure,

thereby losing ecosystem services

of tidal wetlands?

• Tipping points: When do we need

to move altogether?

Rotterdam, The NetherlandsYangtze Estuary

Tian et al.

2015 Journal

of HydrologyBarrier

removal,

Columbia

River estuary

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Mapping the geographic extent of tidal wetlands and trends remains a technology challenge

• Lack of historical consistency in

defining the geographical extent and

terms “coastal” and “tidal”

• Advances in unmanned aerial vehicle

(UAV) technology and geographic

information systems are needed

Plant1

Plant3

Plant2

Water

Right: Flight path, ground-truthing, and image

processing from ongoing research in hyperspectral

methods development for automating vegetation

classification by NOAA NMFS, Pacific Northwest

National Laboratory, RykaUAS, Inc., and the National

Park ServiceDiefenderfer et al. forthcoming

JGR: Earth Surface

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A Challenge for Computing and Modeling

______________ 12.5 km ______________

• A typical grid cell for the

atmosphere/land is ~100km and for

ocean ~50km in Earth System

Models from around the world that

participate in CMIP6 (IPCC).

• For the atmosphere/land, 25km is

considered high resolution

• For the atmosphere/land, 1 – 4 km

is considered ultra-high resolution

(resolving convection).

Thom et al 2018 Ecological Applications;

Diefenderfer et al. 2012 Landscape Ecology

4 km

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Key research needs

• Data gaps block rapid development of tidal wetland carbon markets: soil-atmosphere fluxes (e.g., CH4), lateral fluxes to water bodies, and spatial variation. Consistent with fundamental science needs.

• Models will support:

• Applied: Prediction of benefits of tidal wetland restoration, minimizing costs of monitoring demonstration projects.

• Basic: Higher resolution prediction by Earth Systems Modeling with exascalecomputing for basic science applications

DOE Office of Science, Biological

and Environmental Research,

2017; Ward et al. in revision

Nature Communications;

Kraucunas et al. 2019 AGU

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Conclusions

• Blue carbon and the blue economy are unified by decarbonization and using ocean–coastal environments to improve resilience to global change. Needs:

1. Bridge applied science – planning – basic science gaps: Similar data collection and modeling requirements.

2. Domestic tidal wetland blue carbon demonstration projects in the face of global geopolitical uncertainties.

3. Widely deployed new sensor technology located between the IOOS and NEON networks: study designs to inform 1) resilience planning 2) emerging tidal wetland blue carbon methods, and 3) improvement of models.

4. Simulation models will span applied – basic science research space, allowing for prediction and valuation of benefits, detection of impending tipping points, and minimizing the costs of monitoring.

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Thank youHeida.Diefenderfer@pnnl.gov

Research and collaboration

sponsored by the National Science

Foundation, NOAA, U.S. Army

Corps of Engineers, and U.S.

Department of Energy Office of

Science

Illustrations by Barbara Harmon,

Rose Perry, and K.Timm.