Welcome To Wirral

The Dee is a large funnel shaped estuary which lies between the Wirral Peninsula, England and Flintshire, North East Wales. It was formerly much more extensive but large scale reclamation of intertidal land has occurred, principally at the head of the estuary. This followed the canalisation of the River Dee in the eighteenth century when an attempt was made to secure the continuation of Chester as a port. The estuary contains extensive areas of intertidal sand and mudflats which support a variable but characteristic benthic fauna depending on the nature of the substrate. Large areas of saltmarsh also occur at its head and along part of its north-eastern shore. The estuary continues to accrete and further saltmarshes are developing, particularly on the English shoreline. Locally, on the Welsh shoreline, saltmarsh continues to erode, particularly between Greenfield and Flint. Within the estuary, the three small sandstone islands of Hilbre, Middle and Little Eye provide the only hard natural rock coast habitat along this section of coastline. A largely unvegetated shingle ridge occurs at the Point of Ayr. Although yellow embryo dunes occur at its western end, these are susceptible to erosion from wave action.

The Dee Estuary is one of the most important estuaries in Britain and amongst the most important in Europe for its populations of waders and wildfowl. The estuary is particularly important for its wintering bird populations and both waders and wildfowl achieve numbers of international importance. The estuary supports internationally important populations of a number of wader species, namely, Oystercatcher Haematopus ostralegus, Knot Calidris canutus, Curlew Numenius arquata, Redshank Tringa totanus, Bar-tailed Godwit Limosa lapponica, Black-tailed Godwit Limosa limosa, Grey Plover Pluviatilis squatarola and Dunlin Calidris alpina. The waders utilise the abundant invertebrate populations principally on the extensive intertidal flats, particularly the mudflats. Several wading bird species also make extensive use of the coastal grazing marshes and fields adjoining the estuary for feeding and roosting. Around the estuary are a number of high tide roost sites; principal sites include the Hilbre Islands, the foreshore at West Kirby, the shingle spit at Point of Ayr and the saltmarshes at Oakenholt. Wildlfowl present in internationally important numbers include Pintail Anas acuta, for which the Dee and Mersey have been the principal British wintering estuaries for many years, Teal Anas crecca and Shelduck Tadorna tadorna, whilst Wigeon Anas penelope occur in nationally important numbers.

The Dee Estuary is also an important staging post for migrating birds during both spring and autumn. Nationally important numbers of Ringed Plover Charadrius hiaticula are regularly seen on passage. In addition, the summering flock of non-breeding Black-tailed Godwit, one of the largest in the United Kingdom, is regarded as of national importance.

The Dee Estuary also supports nationally important numbers of breeding Common Tern Sterna hirundo. These birds historically nested on the Burton Marshes where they were frequently inundated by spring tides. They now nest on specially developed habitats on lagoons within the Shotton Steelworks complex. Numbers have shown a slow but steady increase since the 1970's. The large breeding population of Redshank, which utilise the ungrazed and lightly grazed saltmarshes for nesting, is regarded as of national significance.

The Dee Estuary also supports nationally important flocks of Cormorant Phalacrocorax carbo, which occur throughout the year and Great Crested Grebe Podiceps cristatus, peak numbers of which occur in the autumn during the moult.

The Dee Estuary supports extensive areas of saltmarsh vegetation and exhibits a complete succession from early pioneer vegetation colonising intertidal flats through lower, middle and upper saltmarsh types to brackish and freshwater transitions at the top of the shore. Although land reclamation has led to a loss of many of these natural transitions, there are still a number of areas, particularly on the English shoreline, around Neston and Parkgate, where transitions to swamp vegetation still occur. These are dominated usually by Common Reed Phragmites australis and Sea Club-rush Bolboschoenus maritimus. On the Welsh shoreline this habitat feature is limited to areas around Connah's Quay and to the south east of Flint. In north east Wales, swamp vegetation is scarce generally and the more extensive areas adjacent to the estuary, including those at Shotton, are therefore important.

The saltmarshes themselves support a variety of vegetation communities characteristic of estuaries in northern and western Britain. The Dee Estuary supports a large area of marsh dominated by Common Cord Grass Spartina anglica. Its current extent reflects the fact that the estuary continues to accrete following historical land claim. Species such as Glasswort Salicornia sp. and Annual Seablite Suaeda maritima are also present. Much of the saltmarsh remains ungrazed and this has allowed extensive stands of species intolerant of grazing to develop, such as Sea Purslane Atriplex portulacoides. Where grazing intensity has declined in locations at the top of the shore, rank strandline vegetation dominated by Common Couch Elytrigia repens and Sea Couch Elytrigia atherica has developed.

Of particular note within the reclaimed land on the Ministry of Defence ranges adjacent to the estuary, is saltmarsh characterised by Saltmarsh Flat-sedge Blysmus rufus, a species close to its southern limit in north Wales. Although the saltmarshes are generally species poor, the nationally scarce species, Slender Hare's-ear Bupleurum tenuissimum is found at Connah's Quay, at its northern British limit of occurrence.

The three sandstone islands which comprise the Hilbre Island complex represent the only natural hard rock coast within the estuary and are the only examples of this habitat between the limestone cliffs of the Creuddyn Peninsula and the sandstone cliffs of St. Bee's Head in Cumbria. Consequently, the coastal cliffs and the maritime heathland and grassland on the plateau areas above the cliffs represent the only regional examples of these vegetation types. Although the western Hilbre cliffs are too exposed to support vegetation, the sheltered eastern cliffs support Common Scurvy Grass Cochlearia officinalis and Sea Campion Silene uniflora. The nationally scarce Rock Sea Lavender Limonium britannicum occurs together with the regionally scarce Sea Spleenwort fern Asplenium marinum

The Dee Estuary supports a number of other nationally scarce higher plants in addition to those previously mentioned including Portland Spurge Euphorbia portlandica at Point of Ayr, Variegated Horsetail Equisetum variegatum in the vicinity of the Shotton Steelworks, White Horehound Marrubium vulgare in coastal grazing fields at Point of Ayr and White Mullein Verbascum lychinitis on basic slag waste at Shotton and Flint.

The Red Data Book species, Sandhill Rustic Moth Luperina nickerlii gueneei occurs within the estuary towards its mouth on both the English and Welsh shorelines.

The presence of a large herd of Grey Seal Halichoerus gypus, is considered to be of regional interest. These haul out on West Hoyle Bank, though breed elsewhere. The presence of breeding Reed Warblers Acroccphalus scirpaceus, a scarce species in North Wales, in reedbeds in and adjacent to the estuary, is of interest. The presence of the uncommon anadromous fish, Smelt Osmerus eperlnnus, is also of note.

Other information

The Dee Estuary has been designated as a Ramsar Site under the Ramsar Convention of Wetlands of International Importance and as a Special Protection Area (SPA) under the EC Birds Directive (79/409) in July 1985.

The site is nationally important and is listed in 'A Nature Conservation Review' edited by D A Ratcliffe (1977), Cambridge University Press.

This site is contiguous with the following four SSSI: North Wirral Foreshore; Red Rocks; Dee Cliffs; Gronant Dunes and Talacre Warren; and is close to Inner Marsh Farm SSSI.

Hilbre Island together with Middle Eye and Little Eye are managed as a Local Nature Reserve (LNR) by Wirral Metropolitan Borough Council.

A number of nature reserves are managed within the site.

The Dee Estuary lies within both England and Wales.

English Nature's Citation Details

Date notified in England:
Date notified in Wales:
File ref: SJ 28/2
Unitary: Flintshire/Denbighshire/Wirral
Site Name: DEE ESTUARY/ABER AFON DYFRDWY
County: Cheshire County Council
District: Ellesmere Port & Neston
Status: Site of Special Scientific Interest (SSSI) notified under Section 28 of the Wildlife and Countryside Act 1981 (as amended)
Local Planning Authority: Cheshire County Council, Denbighshire County Council, Ellesmere Port 4 Neston Horough Council, Flintshire County Council,Wirral Metropolitan Borough Council
National Grid Reference: SJ 220800
Area: 13,7588 ha, 33,984.2 ac
Area in England: 5,237.1 ha, 12,935.6 ac
Area in Wales: 8,521.7 ha, 21,048.6 ac
Ordnance Survey Sheet: 1: 50,000 108, 116, 117
Date Notified (Under 1949 Act): 1954
Date of Last Revision: 1979
Date Notified (Under 1981 Act): 1984
Date of Last Revision: 1998