The salt marshes dominate the landward edges of the inner Solway estuary and were created through the deposition of sand, silt and mud through the ebb and flow of the tides.
Tides vary in height and frequency and for periods of time, while tides are low, newly-laid down sediments are colonised by plants such as the glasswort. Eventually the roots and leaves of plants trap more and more sediment creating new land.
As you go from the seaward side of the marsh to the landward, the plant communities change. This is a response to salt tolerance by the plants. The more tolerant a plant is of salt the closer it is to the shore, and the least tolerant are furthest away.
The marshes host thousands of wildfowl every winter as their grazing area and they support many breeding birds in the spring and summer.
Most of the Solway marshes are grazing commons and are run by 'marsh-committees' for the purpose of grazing sheep and cattle.
The salt marshes are all designated as Sites of Special Scientific Interest, Special Protection Areas and candidate Special Areas of Conservation.