St Osyth Marsh (EHER 48481)

A large area of well-preserved grazing marsh, known locally as Howland’s Marsh, with good survival of characteristic features including sea walls, raised causeways, relict salt marsh, creeks, fleets, ditches and stetch cultivation earthworks. Red Hill salt making sites are also known to survive. The marsh contributes to the setting of St Osyth Priory. The vegetation is high-quality, species-rich grazing marsh.

2014. Historic Grazing Marsh Project. The marshland, bordered by Flag Creek to the west and St Osyth Creek to the south, was reclaimed by the time of the Chapman and Andre map of 1777. Historic environment character: The area is unimproved grassland with extensive lengths of curving sea walls with borrow dyke, creeks, fleets, straight water filled ditches and raised causeways. The sea walls are the dominant historic landscape feature in the area, and are likely to be medieval in origin, although a post medieval origin is more likely for the easternmost area of marsh. A sluice in the sea wall is recorded on the 1st edition OS map <1>. Buildings and track-ways are also recorded on the OS 1st edition map. Earthwork ramps lead from the sea wall down onto the marsh to allow livestock access. The sea walls will retain evidence for date and construction. The relict salt marsh surface is visible in many places with former creeks and rills showing in varying vegetation, although evidence for improvement in the form of stetch cultivation earthworks is also visible. At least one red hill salt making site has been discovered at the interface between the marsh and dry land to the east. The marshes contribute to the setting of St Osyth Priory. Today they are a nature reserve managed by Essex Wildlife Trust. Character of vegetation: High quality species-rich grazing marsh. Dominated by Sea Couch Etyrigia atherica and False Oat-grass Arrhenatherum elatius, with Spiny Restharrow Ononis spinosa, Sea Clover Trifolium squamosum, Meadow Barley Hordeum secalinum, Sea Beet Beta vulgaris subsp. maritime and Bent Grass Agrostis spp frequent. Sheep’s sorrel Rumex acetosella, Narrow-leaved Bird’s-foottrefoil Lotus glaber, Yarrow Achillea millefolium and Lady’s bedstraw Galium verum also occur. Sea Club-rush Bolboschoenus maritimus and Common Reed Phragmites australis dominant in ditches with Dittander Lepidium latifolium and Water-cress Rorippia nasturtium-aquaticum also abundant. Small areas of Gorse Ulex europaeus and Bramble Rubus fruticosus scrub. Threats: Threatened by drying out, and habitat creation. Shoreline Management Plan Could be subject to Managed Realignment from 2055. <2>