Saltmarshes are net ‘sinks’ of carbon dioxide, according to pioneering research led by the UK Centre for Ecology & Hydrology (UKCEH).
A year’s data from our flux tower on the Ribble Estuary in Lancashire – the first site to measure the full carbon balance of saltmarsh habitat – showed the amount of carbon dioxide absorbed from the atmosphere during spring and summer outweighed what was released during the autumn and winter.
There were similar findings from nearby Hesketh Out Marsh, a restored saltmarsh, which hosts one of six further flux towers on these important but neglected coastal wetlands around Britain’s coastline.
Some 85% of saltmarsh in the UK has been lost since the mid-19th century due to agriculture, development, pollution and climate change. A new report by WWF and Aviva, based on the UKCEH research, highlights the multiple benefits of the country’s saltmarshes.
In addition to removing and storing greenhouse gas from the atmosphere, the wetlands also support wildlife and recreation, filter pollutants and act as natural defences, protecting a total of around £2 billion worth of property and infrastructure In England and Wales.
Providing vital evidence
The UKCEH network of solar-powered flux towers on saltmarshes, which involve a range of different partners, will provide the evidence to help unlock investment in restoration schemes of these important coastal wetlands.
Annette Burden, a biogeochemist at the UK Centre for Ecology & Hydrology (UKCEH), who led the research for the report, The Importance of UK Saltmarshes, said: “We are collecting the evidence needed for the power of saltmarsh to be fully recognised, by demonstrating the multiple benefits of restoring this important coastal habitat.
“The UK Centre for Ecology & Hydrology is continuing to expand the number of sites we study and collect data from, so we can provide essential information about how the amount of carbon absorbed and stored varies over time and in different places around Britain’s coastline. These data could enable saltmarshes to be included within UK greenhouse gas emissions inventories.”
Unlocking investment
Demonstrating the benefits of saltmarshes could unlock private investment to support restoration, through the purchase of carbon credits. UKCEH is leading a consortium of partners to develop a UK Saltmarsh Code, a voluntary certification standard similar to the Peatland Code, which would assure buyers of carbon credits that the climate benefits being sold are real, quantifiable, additional and long-lasting.
The new report also includes early findings from a new network of Surface Elevation Tables – a globally recognised standard for monitoring changes in the height of sediment – to show how saltmarshes respond to sea-level rise. Initial results from the equipment show a mixed picture. Some marshes are adapting, while others including North Norfolk and the Ribble, are struggling, highlighting where restoration is most urgently needed.
There is more information about the benefits and restoration of saltmarshes in our factsheet.