UK Saltmarsh Code: a pilot project

UKCEH are leading a consortium to develop and pilot a UK Saltmarsh Carbon Code – a rigorous and scientifically-based voluntary certification standard, enabling saltmarsh carbon to be marketed and purchased by private investors, thus providing an income stream for restoration projects and supporting the achievement of national net zero goals.

Saltmarsh Blue Carbon in UK and NW Europe

We are excited to share our evidence synthesis of saltmarsh blue carbon in UK and NW Europe, conducted as part of the NEIRF-funded UK Saltmarsh Code project. 

Saltmarsh restoration

The report presents a comprehensive and robust assessment of the evidence quantifying blue carbon in natural UK and NW European saltmarshes, as well as the first comprehensive estimate for restored sites.

Researchers from UKCEH, Bangor University and WWT extracted data from over 30 papers on carbon and full greenhouse gas fluxes in natural and restored saltmarshes. 

We found variable C sequestration rates for restored marshes, which were generally high in the initial years after restoration. Our results point to the importance of considering full greenhouse gas fluxes when considering net carbon benefit of restored marshes, while highlighting the potential of saltmarsh restoration to not only enhance biodiversity, but also to play a role in future efforts to mitigate climate change. 

Key findings

  1. We found high C sequestration rates of newly restored marshes (13.3 ± 15.0 t CO2e ha-1 y-1), with a lack of data on how older restored marshes might differ.
  2. Restored saltmarshes acted as a net source of nitrous oxide, whereas natural marshes acted as a net sink, indicating a need to incorporate greenhouse gas fluxes into potential carbon burial budgets of restored saltmarshes.
  3. We highlight the need for more research on the influence of saltmarsh characteristics (e.g. pH, salinity, vegetation, sediment type) on the carbon and greenhouse gas fluxes of restored saltmarshes.

Evidence Synthesis: Saltmarsh Blue Carbon in UK and NW Europe

Contact the UKCEH team


The consortium includes Bangor University, SRUC (Scotland’s Rural College), WWT (Wildfowl and Wetlands Trust), RSPB (Royal Society for the Protection of Birds), University of St Andrews, Finance Earth, IUCN National Committee UK, and Jacobs.

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The project is funded through the Natural Environment Investment Readiness Fund (NEIRF) and runs from October 2021 – September 2022. The NEIRF, designed by Defra and the Environment Agency, aims to stimulate private investment to improve and safeguard our natural environment. The fund will develop innovative nature projects that provide both environmental benefits and can attract private investment, helping them get ready for investment and therefore creating a pipeline between projects and the private sector.

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