Duddon Estuary Partnership

Sandwich Tern











Sea Bindweed


Natterjack Toad


Sea Spurge


Sea Lavender




Special Qualities

European Marine Site

The Duddon Estuary, nestling between the Lakeland fells and the Irish Sea, is a dynamic and diverse environment. The expanses of sand and mud flats laid down by retreating glaciers thousands of years ago are constantly reworked by the tides providing unique and varied habitats.To protect this unique estuary it is designated as a:

  • Special Protection Area (SPA) under the European Birds Directive,
  • Special Area of Conservation (SAC) under the European Habitats Directive,
  • Site of Special Scientific Interest (SSSI) under the Wildlife & Countryside Act 1981 (as amended), and a
  • Ramsar site (a wetland of international importance under the Ramsar convention).

The Duddon Estuary is an important wildlife site in Europe, in 1998 it was designated as an Special Protection Area (SPA) and later as a Special Area of Conservation (SACs). The areas of seashore and sea form the Duddon Estuary European marine site. Part of the Morecambe Bay European marine site reaches into the southerly section of the Duddon Estuary. To make it easier to manage, the Duddon Estuary SPA and the section of the Morecambe Bay SAC (North of Jubilee Bridge, Barrow in Furness) is dealt with as one geographical unit in the European marine site management scheme. More information can be found on the Morecambe Bay Partnership website who kindly provide information for both the Duddon Estuary and Morecambe Bay.


Special Protection Areas (SPAs)
Sites protected under the European Bird’s Directive are chosen where they support rare, endangered, migratory or large numbers of birds, or their supporting habitats.


Special Areas of Conservation (SACs)
Sites have been chosen where they support rare, endangered or outstanding natural habitats and, or, species of European importance. Any SAC or SPA which includes sea or shore is known as a European marine site.

Why is the Duddon Estuary so Important?

The whole of the Duddon Estuary is special, everyone who lives and works around the estuary will be aware of its beauty, charm and importance for the area. There are some of the estuary’s habitats and species that are of particular significance. The most important ones are referred to as interest features in the European designation.


These are:

  • Internationally important populations of breeding birds, a breeding colony of sandwich terns
  • Migratory bird populations of international importance, especially pintail, knot and redshank, and
  • A regular assemblage of over 20,000 wintering waterfowl (wildfowl, waders and seabirds) and during severe winters numbers may exceed 70,000, including shelduck, red-breasted merganser, oystercatcher, ringed plover, dunlin and curlew.

These birds depend on the presence within the estuary of several marine and terrestrial habitats, which are internationally important in their own right. It is important that these habitats are maintained for the future. The habitats identified as being important are:

  • Shallow coastal waters – which harbour populations of sand eels and sprats, an important part of sandwich tern diet.
  • Coastal lagoons - particularly Hodbarrow lagoon, provide roosting and feeding areas for waterfowl.
  • Intertidal mudflat and sandflats – where waterfowl feed on the high densities of invertebrates such as cockles, tellins, mud snails, crustaceans and lugworms.
  • Intertidal boulder and cobble skears – provide a good base for dense mussel beds, which are an important food source for knot, oystercatchers and dunlin.
  • Saltmarshes – provide both vital feeding and roosting areas. Saltmarsh provides protection for birds which nest on the marsh, such as pintail and redshank, and possess a wealth of food species such as worms, flies and soft leaved plants. On high spring tides thousands of waders congregate on the higher levels of saltmarsh.
  • Slag banks – are important nesting sites for sandwich terns. The main areas are around Millom and Askam.
  • Shingle Banks - sparsely vegetated shingle areas on Walney Island are an important nesting areas for sandwich terns

How will all these interest features be protected?

Under the Habitats and Birds Directives, the relevant authorities around the Duddon Estuary have responsibility for the conservation and management of the European marine site. To continue to ensure protection of the estuary the relevant authorities formed a management group to develop and implement a management scheme. The scheme looks at all the activities that take place in the estuary to see how they affect the interest features, and suggests actions that can be taken to stop damage being done. It is renewed annually. More information can be found here.

What else makes the Duddon Estuary special for wildlife?

The Duddon Estuary is also a Ramsar site, one of a series of important wetlands around the world. The wildlife that has been identified for designation is the natterjack toad, the rich grouping of wetland plants and invertebrates, and again the wintering waders and waterfowl and breeding birds. All of these are also recognised on a national level as a Site of Special Scientific Interest under the Wildlife and Countryside Act (1981) along with the important geological features of Walney Island as a barrier island, being exceptional as it is a product of glacial erosion and reworking, rather than coastal deposition.


The Duddon Estuary supports 20% of national population of the rare natterjack toad. The natterjack toad is only found at 50 sites in the UK, of which 5 are in the Duddon Estuary. Natterjacks need shallow breeding pools and loose material for burrowing into during hibernation.


The estuary is botanically rich with saltmarsh, sand dune and shingle communities, including a nationally rare shingle vegetation community at Haverigg Haws and North Walney. Shingle species include sea sandwort, spear-leaved orache, sea rocket and sea kale. Rising up from the shingle are the mobile and yellow ridged dunes dominated by marram grass with sea holly, sea spurge and sea bindweed. As the dunes become less mobile the grassland is dominated by red fescue, common bent and sand sedge. All the dune grasslands at Sandscale Haws, Haverigg Haws and North Walney support a rich flora with the rare dune helleborine.


Pioneer saltmarsh at the seaward edge of the marsh, supports glasswort and sea blite, landward of the pioneer zones the low-mid marsh supports short turf of common saltmarsh grass. Sea purslane flourishes where the saltmarsh is ungrazed. The mid-upper saltmarsh is dominated by red fescue, because the sea covers this area less often. Other plants supported by grazed mid-upper saltmarsh include sea milkwort and sea arrowgrass, where ungrazed, sea lavender, uncommon and common lax-flowered plants are present. Sea rush occurs on the inland fringes of saltmarsh and there are small pockets of reedbed on the estuary with common reed or bulrush.


As a result of the habitats found at North Walney and Sandscale they support diverse invertebrates. Sandscale Haws moths include coast dart, Portland moth and shore wainscoat, and the dunes also support two Red data book species the digger wasp and solitary bee. Water beetles can also be found in brackish waters around the estuary.


A number of the species and habitats above have Biodiversity Action Plans (BAP) in order to safeguard and enhance their existence. Information on each of these plans is on the UK BAP website www.ukbap.org.uk



If you would like more information about the Duddon Estuary European marine site or a copy of the management scheme, please contact:
Natural England, Juniper House, Murley Moss, Oxenholme Road, Kendal, Cumbria, LA9 7RL
Tel: 0300 060 2122
Fax: 0300 060 3126
Email: northwest@naturalengland.org.uk


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