A salt marsh is a large, muddy area of land where a river joins the sea. * In some salt marshes large sand banks have been built. These stop tides from entering the salt marsh. The level of soil on the salt marsh builds up and the marsh turns into dry land. Local farmers want to turn salt marshes into dry land and other people want to leave it as a salt marsh. Explain why. Use ideas about land use and biodiversity in your answer. – 7628