Horsey Island (EHER 48492)

A range of heritage assets is known from the marsh, including red hills, decoy ponds, stetch cultivation earthworks, counter wall, sea walls and borrow dykes, as well as creeks and straight drainage ditches. There is a single farmstead. The island is connected to the mainland via a causeway. Flora on the island includes Hog’s Fennel Peucedanum officinale, a very rare plant restricted to the local area.

Historic environment character The natural salt marsh island may have begun to be enclosed within seawalls during the late medieval period. Enclosure had certainly begun by the mid- 17th century and was undertaken in more than one stage. A counter wall may indicate that the north-east of the island was reclaimed at a different time to the remainder. The fleets and other natural depressions that survive in some areas of grassland, particularly on the east side of the island, are evidence of former creeks and saltmarsh before the seawall was built. Historically the marsh would have provided grazing for cattle and sheep, although parts of the marsh have also been used in the past for crop production as evidenced in places by surviving ridges and furrows of ‘stetch’ cultivation earthworks. The sea walls are the dominant historic landscape feature on the island, and will retain evidence for date and construction. The reclaimed island has been reduced slightly in from its greatest extent, with an area on the northern point of the island being reclaimed by the sea. The line of the former sea wall is still visible – marked by sunken barges. The well preserved earthworks of a decoy on the east side of the island are also a significant feature. A second decoy pond on the island retains water but has been subjected to re-excavation in recent decades. Field boundaries in the zone are mainly straight drainage ditches and dykes, but some follow the sinuous course of former creeks. There are some hedgerows bordering the fields closest to the farmstead. There has been little boundary loss, although wetland scrapes and reservoirs have been created for nature conservation. Evidence for at least one red hill has been noted in the southern end of the island indicating its significance for the production of sea salt during the late Iron Age and Roman periods. The single farmstead on the island dates from at least the late 18th century and may retain archaeological remains from earlier phases of occupation. In limited locations modern excavations for wetland improvements are likely to have had a negative impact on archaeological deposits, although elsewhere, archaeological deposits will probably be well preserved, with good survival of organic artefacts and environmental deposits. Horsey Island has been identified as ‘Swallow Island’ in the novel Secret Water’s (1939), Arthur Ransome’s sequel to We didn’t mean to go to Sea, and the 8th book in his internationally famous Swallows and Amazons series. Character of vegetation Semi-improved grassland, managed for wildfowl pasture. Grassland dominated by Bent grasses Agrostis spp., Perennial rye-grass Lolium perenne and Red Fescue Festuca rubra. Hog’s Fennel Peucedanum officinale, a very rare plant restricted to the local area and parts of Kent, is frequent. Thrift Armeria maritima, Common Sea Lavender Limonium vulgare and rare Rock Sea Lavender L. binervosum and Lax-flowered sea-lavender L. humile along the sea wall. Threats Threatened by agricultural improvement, drying out and any further habitat creation e.g. wetland scrapes. Shoreline Management Plan Hold the line to 2055 and then eastern end subject to Managed Realignment from 2055