The WWF Saltmarsh Accretion Monitoring Network

The UK coastline includes around 93,000ha of saltmarsh habitat which in some areas can bury carbon at a faster rate than the equivalent area of forest. Sediment collects around the base and roots of saltmarsh plants where it compacts and builds up the banks of the marsh, storing carbon. Sea level rise is projected to vary around the UK, resulting in some saltmarshes becoming more eroded and releasing stored carbon to the atmosphere.

The WWF Saltmarsh Accretion Monitoring Network aims to provide data on saltmarsh elevation change over time in areas experiencing differing sea level rise, providing key data for accurate models of greenhouse gas emissions and carbon storage.

1. Set up pilot research platforms for monitoring sediment accretion at sites representing different projected sea level rise.
2. Quantify sediment accretion and elevation change over two years to infer vulnerability and resilience of flood abatement services.

• Installation of a globally standardised model of Surface Elevation Table (SET) on nine different sites across the UK including areas of high, medium and low projected sea level rise.
• Aboveground sediment addition will be measured over patches of potassium feldspar using the marker horizon soil core method.
• Belowground compaction and elevation will be calculated by measuring the height change above the bedrock with the SET.

These key data of carbon burial rates will contribute towards development of the UK Saltmarsh Carbon Code and inform climate mitigation policies. By collaborating with the Cambridge Coastal Research Unit, this co-designed network aims to build a scalable, transferrable design which can be adopted by others.

Together we will contribute to a broader national picture of sea level rise, carbon storage and the resilience and vulnerability of saltmarshes as nature-based coastal defences.

This project is funded by WWF.