Defra is actively exploring the role of marine nature-based solutions, such as seagrass and saltmarsh restoration, to deliver both carbon sequestration and broader benefits.

Defra is working in partnership with the Department for Energy Security and Net Zero and Devolved Governments – through the UK Blue Carbon Evidence Partnership – to address evidence gaps that currently prevent the inclusion of saltmarsh in the Greenhouse Gas Inventory. Defra Group have funded five flux towers to provide important carbon emissions data for saltmarsh habitats. Alongside investment to deliver a roadmap setting out the steps needed for potential inclusion of saltmarsh in the Greenhouse Gas Inventory. Other marine habitats will be kept in consideration as the evidence base around them develops.

Reflecting this ongoing work, saltmarsh was included within Defra’s Net Zero pathway for Carbon Budgets 4–6 as an early-stage policy.

Natural England (NE) has been working with partner organisations such as the Environment Agency (EA) on a range of projects using nature-based solutions to deliver restoration of our estuaries, coasts and inshore marine habitats, including developing guidance for how this could best be undertaken.

The Restoring Meadow, Marsh and Reef (ReMeMaRe) initiative led by the EA has published a range of useful guidance reports and restoration handbooks on restoring saltmarsh, seagrass and native oyster habitats in estuaries and coasts. The reports help explain the wider benefits that these nature-based approaches have both for nature recovery and healthy ecosystems. A recent report sets out our current knowledge on natural estuary and coastal flood management.

These guides are supported by maps showing potential locations for restoration. The guides describe the wider benefits to local communities from restoring these habitats, including helping improve water quality.

NE has also published evidence on where restoration would be possible for some of our most threatened and declining marine habitats through the Marine Restoration Potential (MaRePo) and MaRePo+ projects. In the Solent, we are aware of a project where oysters are being used as a nature-based solution to improve water quality. NE and Defra are part of a project which released 2000 oysters in 2024.

There are some studies overseas that look at the use of mussels to help improve marine water quality although we are not aware of published guidance for UK waters.

Defra published guidanceon how nature-based solutions may reduce flooding and provide the additional benefit of improving water quality.

The EA published guidance on innovative permitting to water companies to enourage them to trial innovative wastewater treatment schemes using nature-based solutions.

The UK recognises the important role that saltmarsh can play in climate change mitigation, adaptation and resilience. Saltmarsh habitats are also richly biodiverse, benefit fish stocks and provide a crucial buffer from coastal flooding.

Building on this recognition, the UK Government is supporting blue carbon restoration efforts through various initiatives, for example by providing £640,000 funding for domestic blue carbon habitat restoration.

This includes funds to support the development of a Saltmarsh Code to help drive investment flows from the private sector towards nature. This funding has also increased the capacity of the Restoring Meadow, Marsh and Reef initiative (ReMeMaRe), helping to create a pipeline of restoration projects in saltmarsh and other key estuarine and coastal habitats.

Defra has set up the UK Blue Carbon Evidence Partnership in partnership with the Devolved Administrations to address evidence gaps that currently prevent the inclusion of saltmarsh habitats in the UK Greenhouse Gas Inventory (GHGI). Inclusion of saltmarsh in the GHGI and the development of a Saltmarsh Code will allow blue carbon to be marketed and traded as a carbon offset, leveraging private investment into these vital natural carbon stores.

In addition, funding has been made available for saltmarsh restoration through the Landscape Recovery and Countryside Stewardship Environmental Land Management schemes. In the ELMS Countryside Stewardship scheme approximately 5,000 hectares of saltmarsh is being maintained or restored to a good condition.

The £750m of Nature for Climate funding is due to end in March 2025 and the Programme will be delivering against its agreed Business Case in that time. The Fund’s impact is being evaluated and any future funding for Trees, Peat and Saltmarshes will be a matter for the next Spending Review. We are continuing to explore further means of supporting saltmarsh restoration.

The estimation of the impact of anthropogenic activities on seagrass meadows, salt marshes and other blue carbon habitats along the shores of the UK is currently precluded by widespread gaps in the data required to generate emission estimates in line with current guidelines.

We are working with the UK Blue Carbon Evidence Partnership (UKBCEP) to resolve this. As a first step, a roadmap to inclusion of saltmarsh has been created and the UKBCEP are working to collect the necessary data.

The Government recognises that protecting, restoring, and sustainably managing coastal and marine habitats such as saltmarsh, seagrass and native oyster reefs can provide benefits for society, biodiversity and climate adaptation, as well as for carbon sequestration.

We are working to protect these habitats, including through the Marine Protected Area network, which already contains the majority of saltmarsh and seagrass habitats in the UK. A number of estuarine and coastal habitat restoration initiatives are also underway including the Environment Agency’s Restoring Meadow, Marsh and Reef (ReMeMaRe) initiative which aims to reverse centuries of coastal habitat decline by restoring seagrass meadows, saltmarsh and native oyster reefs to bring benefits to people and nature. The Environment Agency’s restoration handbooks and restoration potential maps are also a key tool to support restoration of coastal blue carbon habitats in the UK and beyond.

In addition, the Government’s £80 million Green Recovery Challenge Fund has supported a range of nature recovery projects across England, some which have included saltmarsh and seagrass restoration.

Through the UK Blue Carbon Evidence Partnership, Defra is working with the Department for Energy Security and Net Zero alongside the other UK Administrations to address key research questions relating to blue carbon habitats, such as saltmarsh. In 2022, the UK Government launched its £140 million Natural Capital and Ecosystem Assessment programme, a flagship three-year R&D programme, spanning England’s land, coast and sea. The programme includes mapping of blue carbon stock and sequestration rates in important coastal environments such as saltmarsh habitats, alongside wider ecosystem services which provide societal, ecological and economic benefit.

The Environment Agency’s (EA) Restoring Meadow, Marsh and Reef (ReMeMaRe) initiative is working to restore our estuarine and coastal habitats to benefit people and nature. The EA’s restoration handbooks are a key tool to support restoration of coastal blue carbon habitats in the UK and beyond.

The Government is also supporting eight blue nature finance projects, including blue carbon, with around £750,000 of grants through the Natural Environment Investment Readiness Fund. This funding is being used to develop a pipeline of projects that can demonstrate viable private-sector investment models, ultimately working to restore important blue habitats such as saltmarsh. In addition, our £80 million Green Recovery Challenge Fund has supported a range of nature recovery projects across England, five of which have included saltmarsh restoration.

Through the UK Blue Carbon Evidence Partnership, Defra is working with the Department for Energy Security and Net Zero alongside the other UK Administrations to address key research questions relating to blue carbon habitats, such as saltmarsh. In 2022, the UK Government launched its £140 million Natural Capital and Ecosystem Assessment (NCEA) programme, a flagship three-year R&D programme, spanning England’s land, coast and sea. The programme includes mapping of blue carbon stock and sequestration rates in important coastal environments such as saltmarsh habitats, alongside wider ecosystem services which provide societal, ecological and economic benefit.

The Environment Agency’s Restoring Meadow, Marsh and Reef (ReMeMaRe) initiative is working to restore our estuarine and coastal habitats to benefit people and nature. The EA’s restoration handbooks are a key tool to support restoration of coastal blue carbon habitats in the UK and beyond.

We are also supporting direct investment into saltmarsh restoration through our £80m Green Recovery Challenge Fund, which is supporting nature recovery projects across England. The Government is supporting eight blue nature finance projects, including blue carbon, with around £750,000 of grants through the Natural Environment Investment Readiness Fund. This funding is being used to develop a pipeline of projects that can demonstrate viable private-sector investment models, ultimately working to restore important blue habitats such as saltmarsh.

The Big Nature Impact Fund (BNIF) will be a private sector vehicle and could invest in projects involving saltmarsh habitats that meet its criteria for investment.

Nature-based solutions, including blue carbon habitats such as saltmarshes, have an important role to play in preventing biodiversity loss and supporting adaptation and resilience to climate change, alongside their carbon sequestration benefits. Through the UK Blue Carbon Evidence Partnership, Defra is working with the Department for Business, Energy and Industrial Strategy and the other UK Administrations to address key research questions relating to blue carbon.

In April 2022, HM Government launched its £140 million Natural Capital and Ecosystem Assessment programme, a flagship three-year R&D programme, spanning England’s land, coast and sea. The programme includes mapping of blue carbon stock and sequestration rates in important coastal environments such as saltmarsh habitats, alongside wider ecosystem services which provide societal, ecological and economic benefit. This work will be used to inform marine planning and development decisions.

In the programme’s proof-of-concept year, the Environment Agency (alongside its ongoing role monitoring saltmarsh extent and change), mapped areas within saltmarshes with different capacities to capture and store carbon, bringing the national saltmarsh zonation map up to 96.5% coverage of England’s total saltmarsh habitat.

In addition, Natural England monitors, and assesses the condition of, saltmarsh within sites of special scientific interest.

We are also improving understanding of the impact of climate change on marine and coastal ecosystems. The Marine Climate Change Impacts Partnership (MCCIP) synthesises the latest research and evidence on climate change impacts and predicted trends affecting those ecosystems. Established in 2005, MCCIP engages with a wide range of scientific authors and reviewers to produce updates on the evidence base.