Wetlands for
Carbon Storage
Creating and managing
saltmarshes to store
blue carbon in the UK

A Route Map

The science is clear. Wetlands are the mosteffective carbon sinks on our planet.
Martha Rojas Urrego
Secretary General of the Ramsar Convention on Wetlands, January 2019.

Contents
4 Introduction

12 Proposal

22 Purpose

28 Potential

33 Process

42 Partnerships

47 Policy

6 Executive summary

What are wetlands?

DeliveryInformation

What dowetlands do?

Opportunities forsaltmarsh creation

Delivery

54 Conclusion

Benefits ofsaltmarshes

Capacity building

Capacity building

Plans

Case study: WWT
Steart Marshes

Evidence neededto acceleratesaltmarsh creation

Community
engagement

Community
engagement

Funding

Additional skills
neededProtection andmanagement ofexisting saltmarsh

56 References

What aresaltmarshes?
How do wetlands
help us?
What role dowetlands play intackling climatechange?
How do saltmarshes
store carbon?
What are thechallenges?

Finance
Saltmarshcarbon codeIntroduction

Creating and managing saltmarshes to store blue carbon in the UK

4

Incredible things happen when land and water meet to create wetlands. These extraordinary places teemwith biodiversity, providing homes for endangered and much-loved species. Wetlands are vital ‘service
stations’ for millions of migratory birds, enabling them to rest and refuel. For us, they provide essential
protection against the impacts of the climate crisis, floods, droughts and pollution. We also know thatliving near or visiting a wetland and its wildlife is good for our wellbeing.
Wetlands are the lifeblood of the planet, but they need our help: globally they are disappearing at a rate three times
faster than forests1.
The UK’s wetlands need strong and effective laws
to protect them from harm; they need careful
and well-resourced approaches to manage
them – and they also need restoring. Over thelast 500 years England has lost approximately
90% of its wetlands2,3, and in more recent times
their continuing absence – coupled with further
loss and degradation – has helped fuel some of
the greatest challenges we face: the escalatingclimate crisis, plummeting levels of biodiversity
and a rapid decline in our own wellbeing.
But there’s hope: WWT are pioneers in wetland
conservation. We use ground-breaking science tobring species and wetlands back from the brink
and restore, protect and create wetlands aroundthe world. In 2020, WWT joined calls for a green
recovery to build back better out of the COVID-19
pandemic, and, crucially, for a ‘blue recovery’ to
be at its heart.

We set out proposals for the creation andrestoration of 100,000 hectares of wetlands in the
UK – every single hectare will be filled with wildlife,
providing a much-needed boost to biodiversity
and to the Government’s pledge to halt andreverse the decline of our natural world by 2030.

I hope you enjoy reading our route maps; we lookforward to working with you to create and restore
wetlands that help protect our health and thehealth of our planet.

We are now setting out further details of how
this blue recovery needs to happen, publishing
four route maps for creating wetlands for carbon
storage, urban wellbeing, water quality andflood protection.
Each route map sets out our proposals, thepurpose the wetlands will serve, the potential they
offer, the process involved and the partnerships
and policy framework required to make these
proposals happen.
Sarah Fowler, Chief Executive
WWT (Wildfowl & Wetlands Trust)Executive summary

Creating and managing saltmarshes to store blue carbon in the UK

5

Coastal wetlands provide valuable habitats
for many migratory birds and fish.

A group of black-tailed© Photographer
godwits.
TylerWWT
Moulton/Unsplash
Steart Marshes.

Executive summary

Creating and managing saltmarshes to store blue carbon in the UK

Executive summary
Wetlands play a vital role in limiting the amount of carbon in theatmosphere. Blue carbon (that stored in marine and coastal habitats)is one of the most important carbon stores in the UK.
Saltmarshes, in particular, are very efficient at locking away carbon,
while also bringing a range of additional benefits for people and wildlife.
Damage and destruction of these habitats can result in the release oflarge amounts of greenhouse gases into the atmosphere. Therefore,
protecting, restoring and creating saltmarshes is key to helping increase
our ability to absorb and store carbon from the atmosphere, helping us
tackle climate change. They should be a critical part of the UK’s future‘blue infrastructure’, but they are currently a significantly underused andoverlooked nature-based solution.
We have the information and opportunity to achieve the scale and paceof delivery required, but some key components will need to be in place.
Given the time it could take to deliver them, we must start planning
restoration and creation projects immediately.

Nature-based solutions use thepower of natural ecosystems tohelp tackle major challenges
such as climate change.

The rate of carbon
sequestration by coastal
wetlands is greater thanby all forests combined,
despite forests coveringmuch larger areas.

6Creating and managing saltmarshes to store blue carbon in the UK

Executive summary

Blue carbon is carbon that accumulates and is stored in marine and coastal
habitats as a result of their high productivity and sediment-trapping ability.
Saltmarshes, in particular, can be very efficient at locking away carbon. As theygrow, carbon dioxide (CO2) is drawn out of the atmosphere by the photosynthesisof saltmarsh plants and fixed as organic carbon. When saltmarsh plants die they
become buried in the mud rather than decomposing and releasing their carbon
into the atmosphere. As sea levels rise, more sediment layers get buried and morecarbon is locked in.

CO2
Saltmarsh plants
capture the CO2 andlock away carbon.

7

O2

Mud
C

As saltmarsh plants die
carbon is buried andstored in the soil.

C

Illustration (a) – coastal ecosystem. Saltmarsh and blue carbon burial.

Sediment layers

C

Sea levelC

Wet mud, which contains more plant remains
and carbon, comes in with the tide and isalso trapped by the saltmarsh plants.

C

C

Carbon burialCExecutive summary

Creating and managing saltmarshes to store blue carbon in the UK

8

Proposal
A 2019 Government-commissioned report identified land around the English coast that could berestored to saltmarsh4. According to the estimated potential in this report, we propose that a minimumof 22,000 hectares is restored in the UK by 2050. This should be done alongside effective protection
and management of the UK’s existing 48,545 hectares of saltmarsh5,6,7,8. 22,000 hectares of restoredsaltmarsh would mean an extra 1.5 megatons of carbon dioxide equivalent per year would be captured
and stored (according to the carbon burial rates seen at WWT Steart Marshes). This is equivalent totaking 770,000 cars off the road for one year.

PurposeCoastal wetlands such as WWT Steart Marshes are cost-effective and land-efficient. This is because
they bury more carbon per hectare than other habitats, including forests. They also deliver a range ofother valuable services, including: providing natural flood defences to local communities; filtering out
pollution to improve water quality; supporting local economies through food production and tourism;
offering opportunities for outdoor access to boost wellbeing; and of course providing habitats for an
incredible range of wildlife.

Potential
We have an exciting opportunity to create saltmarshes to provide these benefits. WWT has developed
indicative maps that identify the potential to create 306,688 hectares of new saltmarsh across the UK9.
The existing evidence is persuasive, but we need more data. Existing restored saltmarshes in the UK
have been estimated to store an average of 13.3 tonnes of carbon dioxide equivalent per hectare per
year, compared to 8.2 tonnes in naturally occurring saltmarsh. However, the newly restored saltmarsh
at WWT Steart Marshes saw much higher rates of around 70 tonnes of carbon dioxide equivalent per
hectare per year. Given the high variability of carbon burial rates among restoration sites, it is important
we continue to gather data so that we can derive a more precise average value for blue carbon
storage and prioritise the most effective sites.

Executive summary

Process
Creating saltmarshes to store carbon involves thefollowing three elements:
Delivery: Direct conservation action to create and manage saltmarshes
to store blue carbon and provide co-benefits.
Capacity building: Providing advice and training to landowners andlocal councils, creating innovative financing approaches, and gatheringand sharing further evidence on how to derive multiple benefits
from saltmarshes.
Community engagement: Consulting and involving people in shaping
their local community, from design and governance of saltmarsh creation
projects through to completion and management of sites into the future.
Such projects must serve the community rather than be imposedfrom outside.

Protection and management
This route map focuses on creating and restoring saltmarshes,
but other existing wildlife-rich coastal habitats (such as seagrass,bivalve reefs and kelp) are also crucial to delivering blue carbon
and co-benefits. These valuable resources deserve full protectionand effective management.

Creating and managing saltmarshes to store blue carbon in the UK

9Executive summary

Creating and managing saltmarshes to store blue carbon in the UK

Partnerships

Creating coastal wetlands at scale will
require supportive policies. This means
having the information, plans andfunding in place to allow stakeholders
to create and restore them.

WWT Steart Marshes.

Working in strong effective partnerships will be
key to reaching the target of 22,000 hectaresof saltmarsh. We need the involvement of
national and local governments, the investment
and know-how of businesses, and a processof co-creation with landowners andlocal communities.

10

Executive summary

PolicyCreating saltmarshes at scale will also require supportive policies. We need policies that provide
the necessary information, plans and funding.
WWT is calling on the UK Government to adopt saltmarsh creation as an important part of its plans tomeet its net zero commitment, to help unlock private sector investment in saltmarsh restoration.
Policy priorities
By 2025:
UK Government to include coastal wetland creation as a nature-based solution in the
UK’s Nationally Determined Contribution (NDC)10 and the UK Greenhouse Gas Inventory.
UK Government and devolved administrations to support a nationally recognised
Saltmarsh Carbon Code that sets clear standards for best practice in saltmarsh creation,
restoration and maintenance.
UK Government to put in place funding mechanisms to facilitate the creation andrestoration of coastal wetlands for carbon sequestration, through public and private
sector investment.

Creating and managing saltmarshes to store blue carbon in the UK

11

Creating and managing saltmarshes to store blue carbon in the UK

1.
Proposal
We propose the creation andrestoration of a minimum of
22,000 hectares of nature-richsaltmarsh by 2050, and theprotection of our existing
saltmarsh resource, to maximise
the opportunity for blue carbon
and co-benefits.

Proposal

Creating and managing saltmarshes to store blue carbon in the UK

13

Coastal wetlands such as WWT Steart Marshes are cost-effective and land-efficient because they bury more carbon perhectare than other habitats, including forests. They also deliver a range of other valuable services, such as providing
habitats for many migratory birds and fish, improving water quality through filtering out pollution, acting as a natural
flood defence and providing a wealth of benefits to human health and wellbeing.

What are wetlands?
Wetlands are unique ecosystems that are either
permanently or seasonally inundated with water.
They include lakes, rivers, swamps and marshes, wet grasslands, estuaries,
saltmarshes and human-made sites such as ponds and reservoirs. They range
in size from garden ponds to the Pantanal in Brazil, Bolivia and Paraguay,
which is three times the size of Ireland.

What do wetlands do?
Wetlands hold much of our natural capital.
They also provide some of the essential ecosystem services that make lifeon earth possible, providing nature-based solutions to many of our mostpressing environmental and social problems.

They give us relief from the stresses of modern life and improve the resilienceof communities to the pressures of the climate crisis, pollution and theeffects of urbanisation.
This document sets out how we can realise these benefits.

Natural capital
The world’s stocks of natural assets that
underpin our economy, including geology,
soil, air, water and all living things.

Proposal

Creating and managing saltmarshes to store blue carbon in the UK

14

Illustration (b) coastal ecosystem. How saltmarshes work.

SpringIn spring, the saltmarsh
becomes green and vibrantonce more. New plants startto grow from seeds carried in
the sediment deposited by
the autumn and winter tides.

SummerIn summer, the saltmarsh isrich, green and full of life.
Sea lavender adds vibrantcolour, while redshank probe
the wet mud for worms andlarvae, and build their nests
in grass tussocks.

What are wetlands?
Wetlands are unique ecosystems that Autumn
are either
permanently or seasonally inundated with water.

What aresaltmarshes?
Saltmarshes comprise the upper,
vegetated portions
zones
What
areof intertidal
saltmarshes?
lying approximately between mean high water

They include lakes, rivers, swamps and marshes, wet grasslands, estuaries, salt
marshes and human made sites such as ponds and reservoirs. They range insize from garden ponds in the Pantanal in Brazil, Bolivia and Paraguay, whichis three times the size of Ireland.
11

12
Saltmarshes
upper,
portionsof intertidal zones7, lying
neap tides compriseand meanthehighwatervegetatedspring tides.
approximately
betweenhigh water
They are composedof meana complex
mosaicneapof tides and mean high water
springtides8.
They
arecomposedofacomplexintertidal vegetation, which is characterised mosaic of various intertidal
vegetation
types(salt-tolerant)characterisedplants.
by halophyticby halophytic
They are(salt tolerant) plants. They areimportantimportanthabitats
habitatsfor
formanymanymigratory
migratoryspecies
speciesof bird and fish, with many
areas
protectedbynationalandinternational
designations.
of bird and fish, and many areas are protectedby national and international designations.

© Illustration/Stuart Jackson Carter

How do wetlands help us?
They help combat
climate change by
storing enormous
amounts of carbon.

CO2

They provide
food and act
as nurseries formany commercial
fish species.

They are biodiverse habitats,providing a home for over
100,000 species of animal13.

They support livelihoodsby providing jobs, tourism
and food.
They provide
freshwater for
drinking, cooking
and cleaning.
They protect us
from flooding.

They prevent coastal erosion by
providing a buffer to the sea.
They treat ourpolluted water
without the useof chemicals.

Coastal wetlands like thesaltmarshes at WWT Steart
Marshes store more carbon
per hectare than otherhabitats such as forests.
Steart Marshes is burying
organic carbon at a rate of
approximately:70

WWT Steart Marshes.

tonnes ofcarbon dioxide14(equivalent) per hectare (per year)

Proposal

Creating and managing saltmarshes to store blue carbon in the UK

What role do wetlands play in tackling climate change?
Wetlands, primarily peatlands,
store over a third of the world’s
terrestrial carbon15.

Illustration (c) Carbon burial rates versus terrestrial forest ecosystems (t Cha-1)16

Blue v green ecosystems
Carbon burial rate
(Tonnes of carbon dioxide equivalent buried per hectare per year)

Tropical forests
Temperate forests

0.15
0.19 0.17

Boreal forests

5.06

8.27

Seagrass beds

Mangrove forests

7.97

Saltmarshes

17

Proposal

Damage and destruction of wetland habitats
often leads to large releases of greenhousegases to the atmosphere. Protecting andrestoring coastal wetlands presents an important
opportunity to mitigate carbon emissions,complementing the need for urgent measures
to reduce greenhouse gas emissions. For a full
explanation of the role that carbon plays in climatechange see Appendix 1.
Recent research indicates that blue carbon
habitats have extremely high carbon sequestration
rates (the rate at which they capture and store
carbon). In saltmarshes, carbon is typically
captured 40 times faster than temperate forests17.

Coastal wetlands (mangrove
forests, seagrass beds andsaltmarshes) make up less than
2% of ocean area but are
estimated to be responsible foralmost 50% of carbon burial in
marine sediments18.

Creating and managing saltmarshes to store blue carbon in the UKof this habitat also replaces
How do saltmarshes Creation
high-emission land uses such as intensive
agriculture, adding to the net carbon benefitof the approach. For more details on carbon
store carbon?
sequestration see illustration (a) coastal
Every day on saltmarshes, carbon in the formof sediment is brought in on the tide. When it’sburied in the wet mud decomposition is slowed
down due to the mud’s low-oxygen (anaerobic)
conditions and the carbon gets locked in19.
In addition, when saltmarsh plants die they
become buried in the mud rather thandecomposing and releasing their carbon into theatmosphere. As sea levels rise, more sedimentlayers are buried and more blue carbon is lockedin the mud. Tidal wetlands are considered carbon
sinks because they are able to store the buriedcarbon, stopping it being released into theatmosphere. For more detail on carbon burial
rates in saltmarshes compared to forests see
Table (1) in the Appendix.
Saltmarsh sediment accummulates verticallyin response to sea-level rise. If the habitat ismaintained, carbon can accumulate indefinitely
in some situations20, although the limits to this
response as sea level rise accelerates are unclear.

ecosystem pg 7.

In saltmarshes, carbon
is typically captured
40 times faster thantemperate forests.

18

Proposal

What are thechallenges weface in restoring,
maintaining
and creating
saltmarsh?
In the UK, saltmarsh covers
approximately 50,000
hectares21,22,23,24. It is a relatively
scarce wetland habitat that has
been depleted historically.

Creating and managing saltmarshes to store blue carbon in the UK

19

The existence of saltmarsh is dependent on being periodically flooded and drained by tides.
However, the extent of the tidal reach around much of the UK coastline is restricted by flood defence
embankments (constructed to provide flood protection and in some instances as part of land
reclamation schemes).
These embankments constrain the degree to which saltmarsh can extend inland, which it would
naturally do in response to rising sea levels. Together with rising sea levels, this causes ‘coastal squeeze’(see illustration (d) pg20).

In the UK only 58%
of existing protected
saltmarsh sites are
considered to be in afavourable condition .
25

Proposal

Creating and managing saltmarshes to store blue carbon in the UK

Illustration (d) ‘coastal squeeze’.

1. With embankment constraints andsea-level rise we are losing theupper saltmarsh habitat all aroundour coastline.

Landward reach of tidal waters isfixed by the presence of a seawall

Land at risk tocoastal flooding

Sea level rise

lower marsh

2. Removal or re-positioning of
constraint allows for coastal
habitats to move further inland.

Where defences are set backspace is created for the upper
saltmarsh to develop

pioneermudflat

Sea lavender
Sea purslane
Red fescue grass
Sea arrowgrass
Greater sea spurrey
Sea aster
Scurvy grassmean high spring tide

Salicornia

CCC

New saltmarsh on
carbon rich areaCmean high neap tideCmean low neap tide
C

C

C

C

upper marsh

lower marsh

pioneermudflat20

Proposal

Saltmarsh restoration andmanaged realignment:
Generally in the UK the requirement to restore
habitat has been driven by biodiversity objectives,
either as compensation for loss of habitat
elsewhere or to provide feeding and roosting
habitats for migratory or breeding waterbirds.
Often this restoration is targeted at areas
already under threat from tidal flooding throughmanaged realignment.

Managed realignment is theprocess of setting back coastal
protections, allowing a previously
protected area to be flooded.
Doing so promotes the creationof natural habitats such as
saltmarshes. These natural
defences help to absorb anddissipate the force of the waves.

Creating and managing saltmarshes to store blue carbon in the UK

In the UK, managed realignment has
predominantly been delivered in England by
the Environment Agency and a small number ofenvironmental non-governmental organisations(NGOs). Some examples of private saltmarsh
restoration also exist.

21

A list of managed realignment schemes in the UK
can be found at omreg.net/query-database/.
In the UK, saltmarsh restoration for biodiversity
purposes usually takes place in the same estuarine
system from which saltmarsh was lost.

It is generally agreed that the best and mostsustainable way to create saltmarsh in the UK isby realigning coastal defences26.

Creating and managing saltmarshes to store blue carbon in the UK

2.
PurposeSaltmarshes
provide multiple
benefits, including
carbon capture,
while boostingbiodiversity.
We would like to
see an increase inhealthy saltmarsh
in the UK.

Proposal

PurposeCreating and managing saltmarshes to store blue carbon in the UK

23

What range of benefits do saltmarshes provide?
Carbon sequestration
The Government’s Natural Capital Committee estimated a potential 22,000 hectares of land around the English coastthat could be restored27. If this happened, an extra 1.5 megatons of CO2 equivalent per year could be captured and stored
in the saltmarsh instead of being released into the atmosphere (based on the rates seen at WWT Steart Marshes).
This is equivalent to taking 770,000 UK cars off the road for one year28.
Existing restored saltmarshes in the UK have been estimated to annually store an average of 13.3 tonnes of carbon dioxide equivalent per
hectare per year, compared to 8.2 tonnes in naturally occurring saltmarsh (as shown in table 3). However, at our newly created saltmarshes at
WWT Steart Marshes, the annual figure has been recorded as much higher at around 70 tonnes of carbon dioxide equivalent per hectare per
year (though this may be reduced when we adjust for various influencing factors).
Saltmarshes are natural assets that delivera range of other valuable services. A summaryof the ecosystem services provided by saltmarshes
in addition to carbon sequestration is provided inTable (2) pg 25.

Water quality
Saltmarshes can play a key role in improving
water quality through filtering out pollution.
Studies have found that saltmarshes canabsorb nutrient pollution, plus a range ofother pollutants including pesticides,
metals and hydrocarbons29.

Creating habitats
Saltmarsh is considered a priority habitat in
the UK. Around 40 species of plants grow only insaltmarshes, and of the 293 species of terrestrial
invertebrates that use saltmarshes, 148 use themexclusively30. A wide variety of resident andmigratory waterbirds such as redshanks, little
egrets and brent geese use saltmarshes to breed
and/or spend the winter months. Saltmarshes arealso a vital habitat for birds like dunlin and egrets
that are of conservation concern31.

Saltmarshes are invaluable to several fish speciesof commercial importance. For many centuries
they have been recognised as crucial feeding andnursery areas for them.
UK saltmarshes are conservatively estimatedto be worth around £3 million annually to thecommercial landings of European seabass,
common sole and European plaice32.

Around 40 species ofplants grow only insaltmarshes.

Proposal

PurposeCreating and managing saltmarshes to store blue carbon in the UK

Reducing flood risk

Wellbeing

Coastal wetlands, such as saltmarshes,
can provide natural flood management.
They reduce the energy (or wave power) ofincoming tides, which can cut flood defence costs
and/or reduce the impacts of flooding. Whensaltmarsh is restored, new sea walls are set backfrom the coast. They are protected by the marsh,
and therefore they are less costly to maintain.
A recent study estimated that £33,000 was saved
each year per kilometer of coast where managed
realignment had taken place33.

Wetlands improve our mental wellbeing andcombat mental illness. They do this by providing
tranquil spaces in which to escape from theeveryday stresses of our busy lives; they are a world
away from our daily worries36.

At WWT Steart Marshes, between £500,000
and £900,000 of net annual benefit is derived
from the nature reserve34. This is based on
five ecosystem services alone: food; climate
regulation; recreation and tourism; educationand provision of habitat. It is worth notingthat this study did not take into account thecurrent knowledge on carbon storage rates35.

The benefits of time in nature are now being
recognised by healthcare professionals.

24

These benefits include disease prevention and areduction in the social burden of chronic disease.
The NHS is currently championing the importanceof healthy lifestyle choices and is looking at
options such as social prescribing to help patients
improve their health and wellbeing. WWT alreadyhas a successful ‘blue prescribing’ project at
WWT Steart Marshes.

Proposal

PurposeCreating and managing saltmarshes to store blue carbon in the UK

Table (2). A 2011 estimate of the monetary value of ecosystem services provided by worldwide coastal marshes (shown in hectares per year or ha-1yr-1)37£15.27 ha yr£7,200 ha yr£1,700-32,200 ha

Raw materials (including food provisioning)

Natural hazard regulation

Regulation of pollution
and water purification

-1

-1

-1

-1

Attenuates and/or dissipates waves

Generates biological productivity and diversity-1

Provides nutrient and pollution uptake,as well as retention, particle deposition£2,100-13,900 ha£26 ha yr£32.80 person

Maintenance of fisheries

Organic matter accumulation

Recreation and aesthetics

Provides sustainable reproductive
habitat and nursery grounds, sheltered living space

Generates biogeochemical activity,
sedimentation, biological productivity

Provides unique and aesthetic
submerged vegetated landscape,suitable habitat for flora and fauna

-1

-1

-1

-1

25

Proposal

PurposeCreating and managing saltmarshes to store blue carbon in the UK

26

WWT Steart Marshes was created in 2014 as ahabitat creation scheme to compensate for theloss of saltmarsh in the Severn Estuary. The rate ofloss is likely to increase due to rising sea levels.

Case study
WWT Steart Marshes
Overview
The Environment Agency and WWT in partnership have created a vast
477 hectare wetland in Somerset – one of the largest wetland creation
projects in the UK. It helps mitigate climate change through carbon
burial, while providing a home for wildlife and a special place for people
to enjoy nature. It has also increased climate resilience locally by helping
to protect nearby houses from flooding and by reducing the risks ofcoastal erosion.

Creating and managing saltmarshes to store blue carbon in the UK

Case Study

Research is showing how effective the saltmarshes are in storing carbon.
A team from Manchester Metropolitan University, studying sediments in themarsh, have calculated that WWT Steart Marshes is burying carbon at a
rate of approximately 70 tonnes of carbon dioxide equivalent per hectare
per year (this figure will be reduced when various factors are accountedfor). This evidence is why WWT is calling for saltmarsh to be included into
a new saltmarsh carbon code, just as peatlands and woodlands are.

Over a four year period, over 18,00038 tonnes oforganic carbon was stored at WWT Steart Marshes.

1M+

This is equivalent to the carbon stored by over one
million new trees grown over a 10 year period.

77.9K

Or the greenhouse gas emissions frompowering 77,930 UK homes for one year.

32.9K
Or taking 32,900 cars
off the road for a year.

WWT Steart Marshes also brings other associated benefits. Once intensively
managed farmland, the area is now used to rear saltmarsh beef and lambthat can be sold at a premium price.
The marshes are now home to a vast array of wildlife and support a rangeof breeding and wintering birds, as well as providing shelter for the fryof commercial fish such as seabass. Rare plants have also establishedthemselves in the intertidal area.

27

Creating and managing saltmarshes to store blue carbon in the UK

3.
Potential
There is an exciting
opportunity to create
saltmarshes to provide therange of benefits outlined.
WWT has developed
indicative maps that identify
the potential to create over
300,000 hectares of newsaltmarsh across the UK.

x

The existing evidence ispersuasive, but it is important
we continue to gather data
to prioritise the most effective
sites and better understandthe benefits they bring.
Low tide on the saltmarsh. WWT Steart Marshes

Proposal

PurposePotential

Creating and managing saltmarshes to store blue carbon in the UK

29

What are the specific opportunities
for saltmarsh creation?
The Natural Capital Committee
found a strong economic casefor the creation of 22,000
hectares39 of saltmarsh aroundthe English coastline.
WWT have developed indicative maps forwetland creation and restoration (Figure 1) that
include the potential for new saltmarshes.
For England, we used the ‘Potential
habitat-creation sites within the current
floodplain’ map, developed by the Marine
Management Organisation (MMO)40. It showswhere intertidal habitats (mainly mudflats andsaltmarshes) could be created in existing coastal
floodplains. It highlights areas where techniquessuch as managed realignment and/or regulated
tidal exchange could be used to inundate landthat is currently defended.

To create equivalent maps for Wales, Scotland
and Northern Ireland we closely replicated themethods used to develop the MMO’s map
for England.

The map, together with technical guidance on
the methodology, will be published after further
refinement to remove obvious constraints tosaltmarsh creation.

At this coarse scale, the map identifies 306,688
hectares (ha) of saltmarsh creation potential
across the UK(England: 258,013ha; Wales:
25,762ha; Scotland: 15,591ha; and Northern
Ireland: 7,322ha). It does not account for the
many constraints on managed realignment/
regulated tidal exchange that limit the potential
for saltmarsh creation at a local scale, butemphasises those locations where the mostopportunities are likely to be.

The location of existing coastal habitat-creationsites around the UK coastline is reasonably well
documented and a wide range of research has
been undertaken to determine their success,albeit usually framed around the delivery of
habitat for wildlife to meet biodiversity objectives.

Table (3). Summary of estimated carbon burial by current and potential saltmarsh in the UK.

Extent/opportunity
hectares

Carbon burial rate
tCO2e ha-1yr-1

Annual value
tCO2e ha-1yr-1

Existing UK
saltmarsh extent

48,54541,42,43,44

8.246

394,617

Existing UK coastal
realignment

2,25245

13.34630,590

NCC ambition forsaltmarsh creation

22,00013.3

292,600

Resource

Total (estimated)

717,807

Figure (1). UK indicative Saltmarsh Potential map (see footnote for data sources used to develop map and associated licencing information)
Proposal

1. Northern Ireland47

2.

2. Scotland48
49
3. Wales4. England50

3.

4.

1.

(MM01135 Potential habitat creation sites within the current
floodplain_mudflat/saltmarsh)

onbluethe carbon
map to view
Creating and managing saltmarshes toClickstore
in theenlarged
UK 30
sections in the Appendix.

Proposal

PurposePotential

Creating and managing saltmarshes to store blue carbon in the UK

31

What is the evidence needed to acceleratesaltmarsh creation?
Underpinning our ability to kickstart the creation and restoration of saltmarshes for carbon storage and to drive
the adoption of a UK Saltmarsh Carbon Code, is the need for further evidence.
Given the high variability of sequestration rates
among restoration sites, we urgently need moredata from which to derive a more precise averagevalue, and an understanding of the factors thatcause the variation among sites. This will allow us toprioritise the best sites and unlock their potential.

determine and agree. For example, a proportionof the carbon that arrives on the tide and is buried
would otherwise have been buried in some existing
sediments, and therefore should not be accounted
as additional sequestration, but how we measure
and account for that needs resolving.

The Blue Carbon Evidence Partnership was set
up after COP26 to progress the evidence on blue
carbon habitats. It presents an opportunity to fillthese evidence gaps and support a science-led
strategy to saltmarsh creation.

Understanding carbon sequestration rates andhow they change over time
Similarly, the rate or carbon burial in restoredsaltmarshes is influenced by how they are designed
and how they are managed, but again, thesefactors are not well understood. So, there is not yet
a clear prescription of how to create saltmarshes
for maximum carbon burial rate.

The evidence gaps that need to be addressed are:Understanding how much ‘additional’ carbon
is buried by restored saltmarshes
We know that saltmarshes vary in the rate ofcarbon sequestration, but we do not yet know
exactly what factors cause this variation.
This means that it is not yet possible to predict,with confidence, where we should restore sites for
maximum climate mitigation value.
There are details in how we measure saltmarsh
carbon burial, and account for how much of thatcarbon is new and additional, that we still need to

Newly restored saltmarshes often accumulate
sediment – and so bury carbon – very rapidly.
However, as the site fills with new sediment andstarts to reach equilibrium with the tide, thesediment deposition will slow, and so the rateof carbon burial will slow accordingly. If carbon
credits are sold with a lifespan of multiple decades,
this slowing of the initial rate of burial needs to beaccounted for, but we don’t yet understand how
to predict this.

Better understanding the associated benefits
While we know that saltmarshes bring multiple
benefits and services, our understanding of thisis still somewhat limited. We need research tobetter quantify and predict the pollution and flood
regulation functions, the commercial fish nursery
benefits, and the human cultural benefits.
We also need to create new markets, so thatpayments for these services can be used to support
saltmarsh restoration. This needs environmental
economics research.
Evidence to support community engagement
Creating new saltmarshes by moving sea defences
inland is a major change for local communities.
It can transform the landscape in which they live
and affect their sense of place and feeling of
security from coastal flooding. Therefore, there isa potential for communities to strongly oppose
saltmarsh restoration, rather than welcoming it asan opportunity. Social science research isneeded to understand how best to work with
communities so that they feel agency in thedecision-making process. (For more information
on evidence gaps, see Appendix 4).

Proposal

PurposePotential

Creating and managing saltmarshes to store blue carbon in the UK

What additional skills are needed to unlock the potential
to create more saltmarshes for carbon storage?
As the number of coastal managed realignment examples is relatively limited within the UK, the expertise andexperience of delivering such schemes comes from a small professional pool. We need to build the number ofpractitioners who have the relevant expertise and skills to design and build them.
Additional sources of guidance:
The Saltmarsh Restoration Handbook51 provides
excellent practical guidance on restoring andcreating saltmarsh habitat.
The Blue Carbon Forum offers the opportunity
to bring together government departments,
statutory agencies, non-governmentalorganisations, environmental economists,
academics, coastal engineers, engagement
specialists and site practitioners. They could
be key in outlining the full extent of which
environmental parameters and technical solutions
could efficiently deliver carbon sequestration
within coastal realignment schemes. This would
ensure the full range of benefits of saltmarshes
are realised.
This Forum could advise on the places where
realignment should be prioritised, identify
evidence gaps and communicate best practicein delivery.

32

Creating and managing saltmarshes to store blue carbon in the UK

4.
Process
The process of delivering critical saltmarsh
habitats at scale will require building capacity
through developing evidence, advice andtraining, while engaging the community on
project design and delivery. Protection andeffective management of existing saltmarsh isalso vital to ensure the carbon remains buried.
The process of establishing saltmarshes asa carbon offset will be key to reaching our
22,000 hectare target. However, to ensure thisis done effectively it is important to create atransparent, credible and verifiable approach.
Finalising the Saltmarsh Carbon Code will help
achieve this.

Creating saltmarshes to store carbon
involves the following three elements:
DeliveryDirect conservation action to create and manage saltmarshes tostore blue carbon and provide other benefits.
Capacity building
Providing advice and training to landowners and local councils,
creating innovative financing approaches, and gathering andsharing further evidence on how to derive multiple benefits
from saltmarshes.
Community engagement
Consulting and involving people in shaping their local community,from design and governance of saltmarsh creation projects
through to completion and management of sites into the future.
Such projects must serve the community rather than be imposedfrom outside.

Proposal

PurposePotential

Process

Creating and managing saltmarshes to store blue carbon in the UK

What are the priorities for the creation andrestoration of saltmarshes for carbon storage?
Set out below are the priority actions that will kick-start the creation and restorationof saltmarshes for carbon storage.
Delivery

Habitat creation at scale

The following will demonstrate thebenefits of saltmarsh creation andprotection and create a model forfurther expansion:

Saltmarsh creation will need to accelerate rapidly in order to deliver 22,000 hectares of new
habitat by 2050. These projects take time to deliver and planning has to start now, driven by
government policy, public funding and market-driven initiatives.
There are opportunities to create saltmarsh through existing government-led initiatives, butthese are unlikely to be sufficiently resourced without more designated funding and policy
developments (see Policy section for more detail).
Securing new private finance, initially linked to carbon and biodiversity offsetting but
complemented by other natural capital markets in the future, appears to be the only way toscale up significantly and rapidly.
Blue carbon has not yet been the driver, the funder, or the realised benefit of managed
realignment sites created in the UK. It will be necessary to use the existing expertise andevidence to develop early projects that demonstrate best practice and that deliver carbon
sequestration rates that meet the demands of government and investors, while also deliveringhigh-quality habitats for wildlife and the multiple co-benefits offered by these habitats.
The research and learning opportunities provided by these ‘early adopter’ sites will help fill
evidence gaps and build the business case for new income streams associated with nutrient
neutrality or flood management.

35

Proposal

PurposeCapacity building

Potential

Process

Creating and managing saltmarshes to store blue carbon in the UK

36

Advice and training
Planning, delivering and managing managed realignment sites requires specific skills, expertise andengineering capacity. There are currently relatively few organisations that are willing and able to deliver
habitat creation and management at the scale proposed in this document.
It is therefore critically important that those who have existing skills, resources, capacity, knowledge,
expertise and experience are involved in the early stage of a national restoration/creation programme.
Over time, other bodies will need to be engaged and supported to build their capacity to deliver andit will be necessary to increase the size of the workforce, so that we have the necessary skills to create
saltmarshes effectively.
This should be a significant opportunity for job creation and the education sector should consider
how it can scale up professional training in the different areas of expertise required to meet		
the coming demand.
Evidence
Filling evidence gaps to build confidence in the delivery of blue carbon and co-benefits of saltmarsh
creation requires resourcing. Consistent monitoring of saltmarsh habitats that aligns with the needs ofthe Greenhouse Gas Inventory and the verification requirements of the Saltmarsh Carbon Code will also
be necessary. Aligning methodological approaches will be critical to filling these evidence gaps and toensure there are sufficient people to monitor and verify the success of projects.

Proposal

PurposeCommunity engagement

Potential

Process

Creating and managing saltmarshes to store blue carbon in the UK

Project development
The needs of local people and communities must be central to projects. This goes further thanconsultation, including them in the design, governance and management of projects. This ensuresprojects serve the community and are not imposed from outside.
Project delivery
Community members may be able to get involved in the delivery of saltmarsh management. This canbe done through volunteering programmes and employment of local people. This helps to ensuresaltmarshes are integrated into the lives of the community. It also means people can improve theirwellbeing by working in these natural environments.
Use
Running and facilitating activities that remove barriers to accessing saltmarshes will ensure the benefits
are widespread and equitable. This could include community activities, educational classes and walks,and schools outreach programmes based around projects.
Maintenance
Where appropriate, community involvement in the management of saltmarshes, including
opportunities for sustainable grazing, should bring about better and longer-lasting wellbeing andbiodiversity benefits for sites. Involvement in project design and delivery ensures this is made possible.

37

Proposal

PurposePotential

Process

Protection and effective
management of existing saltmarshes
Given the importance of saltmarsh
for carbon storage, Sites ofSpecial Scientific Interest (SSSI)
notified for the importance of theirsaltmarsh should be an immediatepriority for remedial action andimproved management if they are inunfavourable condition.
We must not forget the benefits of existing
saltmarshes in the drive to create new ones.
The natural saltmarsh resource around ourcoastlines remains threatened by erosion,development and pollution. It is essential thatthe best sites, together with fragments
outside protected area networks, continue
to benefit from site-protection legislation.
These areas must be managed effectively,
have management plans and theresources to deliver them.

Creating and managing saltmarshes to store blue carbon in the UK

38

Proposal

PurposePotential

Process

How will wetlands for carbon
storage be financed?
Carbon markets
Carbon markets can be regulatory (where
governments set the limits on emissions) or
voluntary (where businesses and others are notrequired to limit emissions but choose to do so).
To develop blue carbon markets, policies andpractices requires expertise in the following fields:
habitat restoration planning, 		
design and practicewetland management
climate financewetland greenhouse gas sciencecarbon standards
wetland policy
community engagement and advocacy.

Creating saltmarshes can deliver carbon offsets.
However, to ensure this is done effectively, teamsof stakeholders with the right skills, knowledge
and expertise will be required to build atransparent, credible and verifiable approach.
This will support the delivery of government
schemes while creating, restoring and managing
carbon-rich saltmarshes.

Carbon markets is a term for a
trading system through whichcountries may buy or sell units ofgreenhouse-gas emissions in aneffort to meet their national limits
on emissions.

Creating and managing saltmarshes to store blue carbon in the UK

39

Proposal

PurposePotential

Process

Creating and managing saltmarshes to store blue carbon in the UK

40

Creating a UK Saltmarsh
Carbon Code
There is currently no trading value for UK
blue carbon. This needs to be establishedquickly through the UK Saltmarsh
Carbon Code.
The UK Saltmarsh Carbon Code will generate
carbon offsets through the creation andrestoration of saltmarsh. The finalisation of thiscode will be an important step to monetising
the carbon value of restored saltmarsh. Existingwoodland and peatland carbon codes (which
generate carbon offsets for woodland creationand peatland restoration) demonstrate thesuccess of such codes.
This important code is being developed by the
UK Centre For Ecology and Hydrology, WWT andother partners. The project to develop it is fundedby the UK Government's Natural Environment
Investment Readiness Fund. This project must be
supported until it is completed.

Additional projects that develop tools to stimulate
private investment in saltmarsh restoration will
be needed. Through market testing we haveestablished that sites with multiple benefits
attract investors and could significantly improvetheir returns.
Securing carbon financing for coastal habitat
restoration in the UK can be based on provenapproaches developed elsewhere. For example,
the ‘Bringing Wetlands to Market’ project in the
USA was instrumental in the development of
the first methodology to enable coastal carbon
projects to secure credits through verified
carbon markets. The creation of this (VM0033)
Methodology for Tidal Wetland and Seagrass
Restoration (the ‘Verra approach’)52 involved
several partners. It was adopted in 2015 and is
now available for application.

These methodologies were a significant
achievement. They paved the way for project
developers interested in supporting saltmarsh
creation/restoration to advance the creation of ablue carbon market. They will be used to underpin
the UK Saltmarsh Carbon Code.

Proposal

PurposePotential

Process

Creating and managing saltmarshes to store blue carbon in the UK

41

Creating and managing saltmarshes to store blue carbon in the UK

5.
Partnerships
No single organisation alone will beable to create saltmarsh for blue carbon.
To create saltmarsh at the scale required
we need the involvement of national andlocal governments, the investment andknow-how of businesses, and a processof co-creation with landowners andlocal communities.
We have identified key partners fromacross the UK to facilitate UK-wide
saltmarsh creation.

Proposal

PurposePotential

Process

Partnerships

Creating and managing saltmarshes to store blue carbon in the UK

43

DeliveryGovernment
As well as working to protect existing saltmarsh, the UK Government,
must develop and implement policies that facilitate and scale up therestoration and creation of saltmarsh. WWT will encourage this by:advocating for policies, often in coalition with other organisations
meeting policymakers to discuss barriers to change
working with the All-Party Parliamentary Group for Wetlands toinfluence parliamentary processes and decision-makers.

Key departments:
The Department for Business, Energy and Industrial Strategy (BEIS)
delivers the Greenhouse Gas Inventory and the UK’s Nationally
Determined Contributions, and is therefore important from an evidence
perspective, although delivery of the land-use aspects are part of
Defra’s remit.
The Department for Environment, Food and Rural Affairs (Defra)
as the department responsible for protecting and enhancing nature,including how people interact with nature
The Department for Levelling Up, Housing and Communities (DLUHC)
as the department responsible for planning law. Access to nature andnatural spaces, including saltmarshes, could also be important to
the levelling up agenda. Saltmarsh restoration is a significant
engineering project that would create employment opportunities
in deprived areas.
WWT will work also with statutory agencies that have a stake in thedevelopment and long-term management of restored and createdsaltmarsh, including coastal flood authorities, statutory nature
conservation bodies and coastal local authorities.

Proposal

PurposePotential

Process

Partnerships

Creating and managing saltmarshes to store blue carbon in the UK

44

Business

Civil society

The creation and restoration of saltmarsh at scale will require theinvolvement of a wide range of businesses and companies, including:

WWT will work with other local and national non-governmentalorganisations. We are stronger in coalition. Where our aims overlap withother organisations we will advocate and campaign together for policychanges that increase saltmarsh restoration and creation and underpin
successful financing from the private sector, for example, the UK Saltmarsh
Carbon Code.

ethical investment banks
private entrepreneurial investors
businesses with strong corporate social responsibility policies
landowning organisations or businesses
utility companies, particularly those in the water sector
ethical pension investment companies
developer contributions through existing planning obligations(e.g. Section 106) or Biodiversity Net Gain.
It will be important to develop the principle of an ethical investment model.
Such a model would require a percentage of any carbon profits generated
from the restoration or creation of saltmarsh sites to be invested in a fund.
The fund would be managed and divided between the immediate local
community and future wetland creation. Such a solution would ensure
robust financial support for the local community far into the future.
Additionally, we will work with consultants who have experience ofdeveloping and delivering saltmarsh restoration for private investors.

Proposal

PurposePotential

Process

Partnerships

Capacity building
Government
The Climate Change Committee (CCC) is an independent statutory bodythat advises the UK and devolved governments on mitigating climate change
and adapting to its impacts. It reports to Parliament annually on the progressthat has been made in reducing greenhouse gas emissions. The CCC will be
an important influencer, applying pressure and critical evidence for ramping
up investment and policy developments in blue carbon.

Business
Demand from business for validated, high-integrity carbon credits is at
an all-time high. However, converting this into investment in blue carbon
projects requires robust proof of concept to improve confidence andmanage risk. In turn, this would substantially increase the supply of viable
projects. Evidence should be shared with businesses on potential financial
savings through investment in saltmarshes.

Civil Society
Funded partnerships with academic institutions to deliver the scientificexpertise to fill evidence gaps will be essential to the success of
our ambition.

Creating and managing saltmarshes to store blue carbon in the UK

45

Proposal

PurposePotential

Process

Partnerships

Creating and managing saltmarshes to store blue carbon in the UK

46

Community engagement
Government

Civil Society

Local authorities have a responsibility for planning, flood prevention
and public health. They will therefore be essential partners in ensuringthat the multiple benefits of saltmarsh restoration are considered andthat projects are delivered. We will seek to advise them on how to use themultiple benefits of restored saltmarsh to save money, improve wellbeing
and increase resilience to climate change.

To seek the investment required to support the restoration and creationof saltmarsh we need to show decision-makers and key stakeholders that
there is support for these wetlands; this means raising public awareness,and building meaningful and effective engagement to inspire action.

Members of the community should be involved as equal partners inmaking these changes.

Business
Projects involving developers and water companies should include
community members as equal partners.

It will be essential to work alongside community groups andstakeholders that use coastal spaces. Community engagement at every
stage is vital to ensure the restored saltmarsh meets local needs andbecomes part of community life.
We will also work with community groups and local charities to increase
the skills of their members, and build their capacity so that they can adopt
and manage projects they helped to create and initiate blue carbon
projects of their own.
Through our Wetlands Can! public campaign, calling for 100,000 hectaresof wetlands to be created across the UK, we will continue to raiseawareness of wetlands and their multiple benefits, and inspire people
to support and take action for them.

Creating and managing saltmarshes to store blue carbon in the UK

6.
PolicyWWT wants to see saltmarsh restoration recognised as avaluable contribution to UK Government carbon targets thatwill unlock investment in saltmarsh restoration.
Restoring saltmarsh habitats for blue carbon requires a
supportive policy framework. Stakeholders need the rightinformation, plans and funding to make this happen.
Despite the benefits, coastal saltmarsh is not fully factored
into any government climate change policies or initiatives andis not included in the Government’s Net Zero Strategy.
And while there are currently carbon offsetting codes forpeatland and woodland, no such code exists for saltmarsh.

Proposal

PurposePotential

Process

Partnerships

PolicyCreating and managing saltmarshes to store blue carbon in the UK

48

The UK Government must adopt the following
policies to ensure we can make the very bestuse of saltmarshes .
53

Information
YTO P PR I ORI T Y
Evidence: By 2025, the UK Government needs to incorporate coastal wetland creation as a nature-based solution into the UK's Nationally Determined
Contribution (NDC) and to include it in the UK Greenhouse Gas Inventory.
The Greenhouse Gas Inventory feeds into the UK’s NDC required under the Paris Agreement. Country NDCs outline and communicate their post-2020 climate
mitigation measures, which can include habitat creation and restoration for carbon storage. Currently, the UK Government states that it requires additional
evidence before it can support the inclusion of saltmarshes within the inventory and the NDC. However, there is currently sufficient evidence to support
its inclusion at least at Tier 1. The Government should not wait for more evidence, but should include saltmarshes in its NDC now, and then build in further
evidence as it is produced. It is important that we understand the gaps in the data, facilitate opportunities to fill those gaps and ensure that these data gaps
do not result in a lack of action.
The UK’s carbon budget places a restriction on the total amount of greenhouse gases the UK can emit over a five-year period. The UK has legally binding
carbon budgets, yet there is no budget for wetlands other than peatlands. This is despite the Intergovernmental Panel on Climate Change publishingguidance on including wetlands in national greenhouse gas inventories54. While these do not include coastal ecosystems, the UK does have the option toincorporate them where there is sufficient evidence to do so.

Proposal

PurposePotential

Sites: We are calling for The Environment
Agency to use existing data to identify andpromote geographical opportunities forsaltmarsh restoration and creation around theEnglish coast. This will establish a ‘community of
the willing’ among the landowning community asopportunities for investment arise.
Existing data shows where saltmarshes could
be restored and created around the UK.
There are also planning processes that set out
geographically discrete opportunities for action.
For instance, Shoreline Management Plans (SMPs)
have created helpful ambition for coastal habitat
creation in the UK yet it is clear that this ambition
has not been realised, despite full implementation
being the basis for the estimate of flood risk toproperties55. Currently SMP policy is based on floodrisk, but WWT would like to see a review of SMP
policies to take into account the opportunity for
managed realignment to store carbon.
There is a lot of variation in sequestration rates
and carbon storage values, and, despite theefforts of WWT and partner academics, there is stillwork to be done to establish the factors that makeparticular sites better or worse for blue carbon.

Process

Partnerships

PolicyA process of identifying landowners willing to offer
land for coastal habitat restoration and creation,with associated clear incentives for doing
so, needs to be developed. This will ensure a'community of the willing' is established and thatit can benefit from and be part of the deliveryof the multiple benefits of restored and newly
created saltmarsh outlined earlier in this report.
Guidance: The UK Government needs to provide
clear advice and guidance to local planning
authorities and landowners on saltmarsh
protection, management, restoration andcreation and the public and private financing
mechanisms that will drive investment inthese areas.
Creating a UK Saltmarsh Technical Advisory
Group, made up of technical experts andpractitioners, will be important in guiding
the focus of managed realignment thatmaximises ecosystem services, including carbon
sequestration and storage. This could unlock
the potential to share and benefit from the fastmoving development of projects, new researchon the benefits of saltmarshes and the fundingthat will be available to drive their restorationand creation. This may be best set up under the
auspices of the existing Blue Carbon Forum.

Creating and managing saltmarshes to store blue carbon in the UK

49

There is also an urgent need for those advisinglandowners on future opportunities for funding
land management to have a clear and consistent
list of options, such as carbon offsetting, to end
the current paralysis in decision-making.

Proposal

PurposePotential

Process

Partnerships

PolicyCreating and managing saltmarshes to store blue carbon in the UK

50

Plans
YTO P PR I ORI T Y
PRI OR I
Standards: By 2025, we need to see the UK
Government and devolved administrations
support a nationally recognised Saltmarsh
Carbon Code that sets clear standards for bestpractice in saltmarsh creation, restorationand maintenance.
This code must be prioritised. WWT and partners
have secured funding to develop a carbon codefor saltmarsh but the costs of any additional
work to support its finalisation must be provided
immediately. Based on the Verra approach, theconfidence created by the new UK Saltmarsh
Carbon Code and its governance will help drive
investment and reduce risk to investors.
A Saltmarsh Carbon Code will provide a rigorousand scientifically based voluntary certification
standard for those seeking to market the climate
benefits of saltmarsh restoration, and will giveassurances to voluntary carbon market buyersthat the climate benefits are quantifiable,
additional and permanent. However, to be
successful it will need a supportive policy
framework that enables the establishmentof an effective carbon market for saltmarsh
maintenance, restoration and creation.

Existing carbon codes (such as the Woodland
Carbon Code and the IUCN’s Peatland Carbon
Code) help ensure that habitat created for carbon
storage is genuinely providing the intended
benefits. Producing a saltmarsh code is criticalto ensuring coastal wetlands meet recognised
standards in storing carbon. It should facilitate
the process of developing financing opportunities
around the multiple benefits of coastal wetlands
alongside private investment in saltmarsh creation.
The latter will focus on monetising the valueof blue carbon stores and helping businesses
reach net zero targets and subsequently the UK
Government’s net zero target.

Standards: We are calling on the UK Government
to ensure that protected area networks also
protect blue carbon stored in saltmarshes,
through effective management and restrictions
on damaging activities.
To secure the benefits of the carbon stored inexisting saltmarshes and those being restored andcreated in perpetuity, it is essential that the habitat
remains intact and is managed to avoid any lossof greenhouse gases. Existing site-protection plansand policies should be used to do this.

This will be especially important for saltmarshes
created to deliver carbon credits that only retain
value if the carbon remains locked in the substrate.
Targets: The UK Government should introduce
targets for saltmarsh creation and restorationin the national Flood and Coastal Erosion Risk
Management (FCERM) Strategy for England.
Concern about flooding continues to focus
attention on coastal management. The National
Coastal Erosion Risk Map (NCERM) currently
indicates that by 2060 about 2,000 properties
will be at risk of being lost to coastal erosion56.
In 2023, the Environment Agency will update the
NCERM to ensure it reflects the latest evidence oncoastal erosion and sea level rise.
The Environment Agency’s Restoring Meadow,
Marsh and Reef initiative is looking at ways torestore saltmarsh and other estuarine and coastal
habitats beyond what is needed to compensate
for habitat losses. This is invaluable work but theneed to establish targets for saltmarsh restorationand creation should not be ignored. WWT iscollating evidence for the FCERM to demonstrate
the need for saltmarsh restoration and creation
for natural flood management. In the future, theFCERM should include and drive the delivery of
the 22,000 hectare target for saltmarsh.

National Flood and Coastal Erosion Risk Management (FCERM) can sometimes cause the lossof saltmarsh. When building and maintaining FCERM assets, the Environment Agency currently
compensates for designated habitats impacted negatively by any activity.

Proposal

PurposePotential

Process

Partnerships

PolicyCreating and managing saltmarshes to store blue carbon in the UK

52

Funding
YTO P PR I ORI T Y
Public funding: We are calling on the UK
Government to put the funding mechanisms inplace to facilitate the creation and restorationof coastal wetlands for carbon sequestration
through government and private investment
by 2025 (using existing initiatives that are wellplaced to do so).
The scale of saltmarsh creation and restorationthat WWT is calling for will need public andprivate funding. The current challenge arounddelivering an effective private market in saltmarsh
creation and restoration relates to corporate risk
and uncertainty. There is a need to bridge thegap between corporate funding of pilot schemes
and scaled-up wetland restoration projects.
Government could provide a range of financial
mechanisms such as guarantees or seedfunding to help bridge this gap and reduce risk
and uncertainty.
There are a range of Government funds that
could deliver coastal wetland restoration,
creation and management. These include theEnvironmental Land Management Schemes(ELMs), which are based on the principle of‘public money for public goods’ and the UK

Infrastructure Bank, which has been allocated£22 billion to deliver objectives including
addressing climate change.
The Government is open to reviewing the casefor broadening the UK Infrastructure Bank
environmental objectives (for example, improving
the UK’s natural capital). If this is achieved it could
leverage financing options such as seed funding
and guarantees for investors to facilitate pilots
to assess their commercial viability. There is also
an opportunity to direct existing and relevant
funds, such as from the Nature for Climate Fund,
Biodiversity Net Gain, FCERM funding, to financesaltmarsh restoration and creation.

Private funding: We are calling for a bespoke
fund to support the development of aninvestment case that drives saltmarsh restorationand creation projects so that carbon buyers
can provide the finance for these projects while
securing a return. Project development costs at
this early stage of market development need tobe met before investors will be attracted tothe proposition.

We need to be in a position whereby thedevelopment, delivery and long-term
maintenance of saltmarsh restoration projects
are partially funded by the carbon offsetting
opportunities that they provide (Table 2 pg25).
In the early stages, funds will be needed to cover
the upfront costs of project development phases.
These projects will ultimately deliver private
investment streams and de-risk early investments.

Unsplash.

Creating and managing saltmarshes to store blue carbon in the UK

Conclusion
WWT proposes the creation and restoration of a minimum of
22,000 hectares of nature-rich saltmarsh by 2050, and theprotection of our existing saltmarsh resource, to maximise thishabitat’s significant blue carbon storage potential and co-benefits.

We need urgent action to plan and establish projects that create andrestore saltmarsh, to deliver blue carbon and a range of co-benefits.
This will require public and private investment, and a blend of the two, todeliver at the scale required. We need to build the capacity of stakeholders
to create these habitats, primarily through managed realignment.
Engaging with communities to co-create projects at all stages will be
crucial to the creation of saltmarshes for carbon and co-benefits that sit at
the heart of community life.

By restoring and creating
saltmarsh at scale we
can increase resilience
to climate change, boost
biodiversity, reduce flood
risks, improve water quality
and improve the wellbeingof people who accesscoastal wetlands.

These are WWT’s proposals to restore, create andmanage saltmarshes to store blue carbon and deliver
so many co-benefits in the UK. We are already leading
the way, protecting and managing existing and newsaltmarshes while building the evidence base, pressing
for further government support and policy changes,
and inspiring new financing mechanisms to deliver atscale with the private sector.
However, we know there is huge potential to do a
lot more. Unlocking this requires determined efforts
by local and national governments, businesses andcommunities across the country.
The opportunity is now. With partnerships, funding
and policy change we can do so much more to build a
network of multi-benefit saltmarsh habitats that help
address the climate emergency. The summer droughtsof 2022, heatwaves and increased flooding haveshown us that there is no time to waste. We need to act
now to mitigate and adapt to the impacts of climatechange. Please join us so that together we can make a
blue recovery happen.

References
Page 41
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Boorman, L.A., 2003 Saltmarsh Review. An overview of coastal saltmarshes, their dynamic
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9

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the role of vegetated coastal habitats in sequestering CO2. Frontiers in Ecology and theEnvironment 9, 552–560.
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Hopkinson, C.S. 2020. Net ecosystem carbon balance of coastal wetland-dominatedestuaries: Where’s the Blue Carbon? In Windham-Myers, L. et al. 2020. A Blue Carbon Primer:
The state of coastal wetland carbon science, practice and policy. Pp. 51-65. CRC Press,
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Phelan, N, Shaw, A & Baylis A, 2011. The extent of saltmarsh in England and Wales: 2006–
2009. Environment Agency, Bristol, UK. Scotland.
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Haynes, T.A. 2016. Scottish saltmarsh survey national report. Scottish Natural Heritage
Commissioned Report No. 786. Northern Ireland.
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and sensitivity characteristics for conservation and management. JNCC Report, No. 334.
JNCC, Peterborough, UK.

Jones L et al. 2011. Chapter 11: Coastal Margins. In: The UK National Ecosystem Assessment
Technical Report. UK National Ecosystem Assessment, UNEP-WCMC, Cambridge.

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Analysis and Valuation of Ten Different UK Sites (White Paper). https://www.abpmer.co.uk/
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For the Natural Capital Committee, eftec, London.
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1.5 megatons of CO2 equivalent per year was estimated according to the carbon
sequestered at WWT Steart Marshes; Mossman HL, Dunk RM et al., 2021.w Rapid carbon
accumulation at saltmarsh restored by managed realignment far exceeds in site
construction. Manchester Metropolitan University BioRxiv
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SC030220. https://assets.publishing.service.gov.uk/media/602bf8d8e90e070556671435/
Saltmarsh_management_manual_Technical_report.pdf
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and sensitivity characteristics for conservation and management. JNCC Report, No. 334
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Concern in the United Kingdom, Channel Islands and Isle of Man and second IUCN Red List
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McCormick, H. et al. 2021. Using a residency index to estimate the economic value of
coastal habitat provisioning services for commercially important fish species. Conservation
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da Silva, L. et al. 2014. Ecosystem services assessment at Steart Peninsula, Somerset, UK.
Ecosystem Services 10: 19-34.
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realignment far exceeds carbon emitted in site construction. bioRxiv doi: https://doi.
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Reeves, Jonathan P., Conor H. D. John, Kevin A. Wood, and Phoebe R. Maund. 2021. "AQualitative Analysis of UK Wetland Visitor Centres as a Health Resource" International
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Barbier, E. B., Hacker, S. D., Kennedy, C., Koch, E. W., Stier, A. C., & Silliman, B. R., 2011. The
value of estuarine and coastal ecosystem services. Ecological Monographs, 81(2), 169–193.
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Marine Management Organisation, 2019. Identifying sites suitable for marine habitat
restoration or creation (MMO1135), UK Government
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England: Environment Agency, 2022. The extent and zonation of saltmarsh in England:
2016-2019. An update to the national saltmarsh inventory. Environment Agency, Bristol, UK.
Wales.
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Phelan, N, Shaw, A & Baylis A, 2011. The extent of saltmarsh in England and Wales: 2006–
2009. Environment Agency, Bristol, UK. Scotland.
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Haynes, T.A. 2016. Scottish saltmarsh survey national report. Scottish Natural Heritage
Commissioned Report No. 786. Northern Ireland.
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Boorman, L.A., 2003 Saltmarsh Review. An overview of coastal saltmarshes, their dynamic
and sensitivity characteristics for conservation and management. JNCC Report, No. 334.
JNCC, Peterborough, UK.
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ABPmer, 2017. UK Marine Habitat Creation Schemes, A summary of completed managed
realignment and regulated tidal exchange projects (1991 – 2016), ABPmer White Paper,
Report No. R2781.
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in UK and NW Europe – evidence synthesis for a UK Saltmarsh Carbon Code. Report to
the Natural Environment Investment Readiness Fund. UK Centre for Ecology & Hydrology,
Bangor. 36pp.

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Wales: Derived from the Flood Map for Planning Zone 3 data layer, which contains Natural
Resources Wales information ©Natural Resources Wales and Database Right. All rights
Reserved. Some features of this information are based on digital spatial data licensed
from the Centre for Ecology & Hydrology ©NERC (CEH). Defra, Met Office and DARDRivers Agency ©Crown copyright. ©Cranfield University. ©James Hutton Institute. Contains
OS data ©Crown copyright and database right 2015. Land & Property Services ©Crown
copyright and database right. The resulting layer was derived using digital spatial data
licensed under Open Government Licence for Public Sector information. ©ABPmer. Contains
Natural Resources Wales information ©Natural Resources Wales and database right.
©Natural England copyright. Contains OS data ©Crown copyright and database right 2022.
©National Trust. ©Environment Agency copyright and/or database right 2015. All rights
reserved. ONS Intellectual Property rights.
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Scotland: Derived from 1. Digital spatial data licensed under Open Government Licencefor Public Sector information: ©Environment Agency copyright and/or database right 2019.
All rights reserved; Crown copyright Scottish Government, SEPA and Scottish Water, 2012,
Copyright Scottish Government and SEPA, 2014). Crown copyright Scottish Government
and Fugro, 2020 & 2021; and 2. NASA JPL, 2013. The derived layer was refined using data
licenced under Open Government Licence: ©Natural England; Copyright National Recordsof Scotland; Ordnance Survey data ©Crown copyright and database right, 2021. ©SNH and
SEPA. Contains OS data © copyright and database right 2022.
49
Northern Ireland: Derived from NASA Shuttle Radar Topography Mission (SRTM) (NASA JPL,
2013) and data licensed under Open Government Licence for Public Sector information:©Environment Agency copyright and/or database right 2019. All rights reserved. The derived
layer was refined using data licensed under Open Government Licence and Strong et al.,2021.
50
England: ©Marine Management Organisation copyright and/or database right 2020. All
rights reserved. Contains public sector information licensed under the Open Government
Licence https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
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https://catchmentbasedapproach.org/learn/saltmarsh-restoration-handbook/Page 40
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Yamashita, H. 2022. Coastal Wetland Restoration. Public perception and community
development. Routledge, UK. VERRA 2021. VM0033 Methodology for Tidal Wetland andSeagrass Restoration, v2.0 (Source: https://verra.org/methodology/vm0033-methodologyfor-tidal-wetland-and-seagrass-restoration-v2-0/)
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United Nations / Framework Convention on Climate Change 2015, Adoption of the Paris
Agreement, 21st Conference of the Parties, Paris: United Nations
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IPCC 2014, 2013, Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas
Inventories: Wetlands
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Defra 2011. Shoreline management plans: guidance. Guidance on the preparation of
second generation Shoreline Management Plans (SMP) (Source: https://www.gov.uk/
government/publications/shoreline-management-plans-guidance)
53

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Environment Agency 2022. Flood and coastal erosion risk management report: 1 April
2020 to 31 March 2021 (Source: https://www.gov.uk/government/publications/flood-andcoastal-risk-management-national-report/flood-and-coastal-erosion-risk-managementreport-1-april-2020-to-31-march-2021)

Appendix
Appendix 1:
What is carbon’s role in climate change?
Global atmospheric carbon dioxide levels are now consistently above
400 ppm, well beyond levels occurring in the last 800,000 years1.
This rise has been driven by human activity with fossil fuel emissions
becoming the dominant source of carbon dioxide from the 1920s
onwards. Reducing greenhouse gas emissions by transitioning awayfrom fossil fuels is necessary to stabilise our climate. To avoid theworst effects of climate change, science tells us that we must limit
global temperature rise to 1.5 degrees Celsius, or a maximum of 2
degrees Celsius, above pre-industrial levels, also the central goalof the 2015 Paris Agreement . Whilst the reduction in emissions is
critical, we also need to do more to improve the management of ourbiosphere, recovering terrestrial and ocean sinks as a form of natural
climate mitigation.

down to approximately 22 tonnes of carbon dioxide equivalenthectares per year. This calculation is made using the Verra code,
which is the most applicable carbon code method for the UK market
due to its robustness.

This review should ensure that SMPs are up to date and use the best
available evidence for their recommendations. It is hoped this will
support planning and investment at the coast, including the creationof saltmarsh at scale.

A further area of uncertainty relates to the timescales of rapid carbon
burial in restored saltmarshes. Ultimately, the rate of carbon burial atsuch sites will fall back towards those of natural sites, but it is not yet
clear whether that takes place over years, decades or centuries.
This is important for carbon accounting.

The SMP process varies across the UK. In England and Wales it isoverseen by the Environment Agency, in Scotland by local authorities
and in Northern Ireland by the Department for Infrastructure Rivers(which has yet to create any).

A remaining priority for research through to policy is to determine
additionality6 (to within reasonable confidence levels) to guideavailability for emerging offsetting markets. Standardising the sampling
methodology used by researchers at different sites is another.
Appendix 4:

The UK is legally committed to reaching net zero emissions ofgreenhouse gases by 20502, with an interim commitment to a
78% reduction from 1990 levels by 20353. Meeting this target will
require not just emission reduction, but also the active removal ofgreenhouse gases from the atmosphere, particularly carbon dioxide,
as determined by the UK Climate Change Committee4. While new
and untested technological solutions are being developed,
we know natural systems already remove carbon dioxide fromthe atmosphere5.

Research gaps for saltmarshes

Appendix 2:• estimating carbon sediments to a depth of 1m so that accurate
carbon stock estimates can be produced for UK saltmarshes, andmake these values comparable with each otherHow newly restored saltmarsh stores carbon
Newly restored saltmarshes created by breaching a sea wall
(managed realignment) are often lower in elevation than naturalsaltmarsh. Consequently, the accumulation of sediment tends to bevery rapid in the early years after restoration as the tidal patterns
stabilise. This means that restored saltmarshes tend to have unusuallyhigh initial rates of carbon sequestration. It is currently unclear how
long these high rates are sustained for; this is likely to depend on
how far away the saltmarsh is from stabilising. Typically, saltmarsh
restoration takes place on land previously used for intensive farmingthat was a net source of greenhouse gases, enhancing the change innet carbon emissions upon restoration.
Appendix 3:
How saltmarsh carbon sequestration is calculated and credited
Saltmarsh creation stimulates new carbon sequestration. Some of theburied carbon arrives as dead organic matter on the ride, rather thanbeing produced by photosynthesis on site. If the carbon that is buriedin the saltmarsh would have been permanently buried elsewhere, it
should not be credited to the new saltmarsh. Various approaches
to this have been suggested and the issue is not resolved for UK
saltmarsh carbon. However, a preliminary estimate of the deduction
for Steart is that it would bring the carbon that could be credited

There is much to be learned about the benefits of saltmarsh and there
is a great need for scientific research to fill the evidence gaps thatprevent more saltmarshes from being created.
However, to provide some of the answers needed to drive theadoption of a UK Saltmarsh Carbon Code and for saltmarshes tobe included in the UK Greenhouse Inventory, new research, andgovernment funding for this research, should focus on:• recording environmental variables such as salinity, sediment typeand elevation for both natural and restored marshes where carbon
and greenhouse gas fluxes are being measured, so that major
drivers of variation in these processes can be identified• obtaining before and after data for natural and restored marshes(where possible) and more data on restored marshes generally andover time, to fully compare the responses of restored marshes with
their natural ‘equivalents’• assessing the additional ecosystem benefits of restoration projects,
including the value of the natural capital secured by new sites.
Appendix 5:
Existing Government initiatives that could help build saltmarsh (asmentioned in the Policy section of this report)
Shoreline Management Plans (SMPs)
The UK Government is working with coastal authorities to review the
SMPs developed between 2006 and 20127. The Environment Agency iscoordinating the work with support from the Coastal Groups.

There is a need for further strategic alignment across the UK to ensure
SMPs are consistently and successfully implemented in all areas.
Habitat Compensation Programme
Most future saltmarsh losses are expected to arise from coastalsqueeze. Compensation in these cases normally involves creating new
habitat. The Environment Agency produces long-term forecasts forhow much habitat it expects will be lost to coastal squeeze8.
Since the early 2000s, the Environment Agency has had a Habitat
Compensation Programme. This programme plays an importantrole in monitoring habitat gains and losses. Since its creation, theEnvironment Agency has created over 900 hectares of intertidal
habitat (saltmarsh and mudflats)9. Despite this progress, theEnvironment Agency expects to see an overall net loss of coastal
habitat as a result of sea level rise over time. The Environment Agency
is leading the Restoring Meadows, Marsh and Reef initiative. This
project is looking at ways to restore saltmarsh and other estuarine
and coastal habitats beyond what is needed to compensate for
habitat losses. It shares experience on facilitating funding, guidance
and regulatory issues when undertaking estuarine and coastal
restoration projects.
National Flood and Coastal Erosion Risk Management (FCERM)
In October 2020 the Environment Agency provided a ‘healthcheck’ report for each SMP to the relevant Coastal Groups10. The
report highlighted areas of concern in realising the management
objectives in the SMPs. The Agency also shared guidance to highlightdevelopments in government policy that might influence the plans.
The new guidance sets out how to make SMPs clearer for those using
them to make decisions, and the Coastal Groups have used theguidance to clarify management approaches in each SMP.
In January 2021, the FCERM Research and Development Programme
published new research on the causes of coastal squeeze and how
it can be measured and predicted11. As part of the SMP review, theEnvironment Agency has updated the understanding of coastal
saltmarsh losses or gains over the last ten years . We want to see
these projects improving the consistency and reliability of the Habitat
Compensation Programme and driving more saltmarsh creation.

Table (1). Carbon burial rates and global area of saltmarsh and terrestrial forest ecosystems (tCha-1)12

ECOSYSTEM

Carbon burial rate(mean tCO2e ha-1yr-1)

Global area
(km2)

Global carbon burial(mean Tg C yr-1)

Saltmarsh

7.97 ± 0.88

22,000-400,000

5– 87

Mangrove

8.27 ± 1.43

137,760-152,361

31– 34

Seagrass

5.06 ± 1.39

177,000-600,000

48-112Temperate forest

0.19 ± 0.037

10,400,000

53

Tropical forest

0.15 ± 0.018

19,622,846

79

Boreal forest

0.17 ± 0.077

13,700,000

49

Appendix reference
1
United Nations / Framework Convention on Climate Change (2015)
Adoption of the Paris Agreement, 21st Conference of the Parties,
Paris: United Nations

The UK Government (2019), The Climate Change Act 2008 (2050
Target Amendment) Order 20192

3
Committee on Climate Change (2020), The Sixth Carbon Budget:The
UK's path to Net Zero.

Committee on Climate Change (2020), The Sixth Carbon
Budget:The UK's path to Net Zero.

4

5
UNESCO, (1971) The Ramsar Convention on Wetlands ofInternational Importance Especially as Waterfowl Habitat

Greenhouse Gas Management Institute and the Stockholm
Environment Institute. Carbon Offset Guide https://www.offsetguide.
org/high-quality-offsets/additionality/

6

7
https://www.gov.uk/government/publications/flood-and-coastalrisk-management-national-report/managing-flood-and-coastalerosion-risk-management-report-1-april-2017-to-31-march-2018https://www.gov.uk/flood-and-coastal-erosion-risk-managementresearch-reports/what-is-coastal-squeeze

8

https://www.gov.uk/government/publications/flood-and-coastalrisk-management-national-report/managing-flood-and-coastalerosion-risk-management-report-1-april-2017-to-31-march-20189https://www.gov.uk/government/publications/flood-and-coastalrisk-management-national-report/flood-and-coastal-erosion-riskmanagement-report-1-april-2020-to-31-march-202110

https://www.gov.uk/flood-and-coastal-erosion-risk-managementresearch-reports/what-is-coastal-squeeze

1112
McLeod, E. et al. 2011. A blueprint for blue carbon: toward an
improved understanding of the role of vegetated coastal habitats
in sequestering CO2. Frontiers in Ecology and the Environment 9,552–560.

Figure (1). UK indicative Saltmarsh Potential map (see footnote for data sources used to develop map and associated licencing information)

1. Northern Ireland2.

2. Scotland
3. Wales2.

4. England

1.

3.

4.

1.

(MM01135 Potential habitat creation sites within the current
floodplain_mudflat/saltmarsh(1))

Click here to return tothe main document

Figure (1). UK indicative Saltmarsh Potential map (see footnote for data sources used to develop map and associated licencing information)

1. Northern Ireland2.

2. Scotland
3. Wales4. England

3.

4.

1.

3.

4.

(MM01135 Potential habitat creation sites within the current
floodplain_mudflat/saltmarsh(1))

Click here to return tothe main document

There are many exciting opportunities to accelerate the creationof wildlife-rich saltmarsh. Whether you’re interested in working
with WWT on a project, assisting others in building the capacity of
stakeholders to create coastal wetlands, or helping us put in place
the policies needed to do so, we’d love to hear from you.
Together we can help secure a future where healthy wetland
nature thrives and enriches lives.

To find out more and read the full report on wetlands forcarbon storage visit wwt.org.uk/blue-recovery

Tom Fewins
Head of Policy & Advocacy
tom.fewins@wwt.org.uk© WWT (Wildfowl & Wetlands Trust) 2022. Registered charity no. 1030884 England and Wales, SC039410 Scotland. © WWT images