St Helen’s Duver

Shoreline management plan – St Helen’s and Bembridge Harbour

The Duver is a small sand and shingle spit developed from the northern bank of the estuary of the River Yar, enclosing saltmarsh. There is a low ridge of blown sand on its eastern, seaward side, protected from natural processes of erosion and deposition by a seawall along the eastern margin, built in the 1890s. The tip of the spit, beyond some houses and other buildings, appears to be accreting. The transition of saltmarsh on the west side of the spit is interrupted by an earth bank seawall which marks the edge of a former tidal mill pond. The bank is ineffective in keeping out tidal incursion at the northwest end of the site, where natural transition from terrestrial to saltmarsh habitat had developed. A golf course was constructed on the Duver during the 1890s, using turf imported from Cumberland, but there is now little or no evidence of these.

The main nature conservation interests of the site are:

  • Its very rich flora and invertebrate fauna
  • The presence of dune grassland habitat

St Helen’s Duver

  • Sand and shingle spit across the north side of the mouth of River Yar estuary
  • Stabilised ‘grey dune’
  • Sand blown in from east
  • 1890s stabilised by sea defences
  • 1890s turned into a golf course
  • 1961 donated to the National Trust
  • An SSSI – rare invertebrates and plants
  • Sea Buckthorn introduced in the 19th Century
  • Popular with residents and holiday makers – pressure on sand dune habitat

Management of the Duver

  • The need for nature conservation
  • Only example of a fixed sand dune on the Isle of Wight
  • The most species-rich coastal dune acid grassland in England
  • A very rich flora on a range of habitats
  • 11 nationally scarce plant species (smooth catsear, autumn squill, dune fescue) and many others which are rare on the Island
  • 9 RDB invertebrate species and 28 nationally scarce species, e.g. the Bee Wolf (Philanthus triangulum), a solitary wasp that predates on bees to feed the larvae (adults feed on nectar and pollen)
  • 2 RDB moths

Problems

  • Car park
  • Mountain and scrambling bikes
  • Barbecues and bonfires
  • Concentrated trampling leads to blow-outs
  • Dog fouling – artificial nutrient enrichment
  • Rabbits – overgrazing, droppings enrich soil
  • Sea buckthorn and hawthorn encroachment

Bembridge Point

  • Short, sandy spit on the south side of the mouth of the River Yar estuary
  • A developing ‘yellow dune’
  • Sand blown in from prevailing south-west
  • Sea buckthorn invading
  • Plants colonising the mobile sand are highly adapted to the harsh environment
  • Café and car park with beach access creates trampling pressure
  • Apartment blocks have been built adjacent to the dune

Reference:
National Trust Biological Evaluation, 1998: St Helen’s: The Duver, Isle of Wight

© Medina Valley Centre 2017. Charity Reg No: 236153.