The Duddon Estuary is the sandy, gritty estuary of the

River Duddon The Duddon is a river of north-west England. It rises at a point above sea level near the Three Shire Stone at the highest point of Wrynose Pass (). The river descends to the sea over a course of about before entering the Irish Sea at the Dud ...

that lies between

Morecambe Bay Morecambe Bay is a large estuary in northwest England, just to the south of the Lake District National Park. It is the largest expanse of intertidal mudflats and sand in the United Kingdom, covering a total area of . In 1974, the second larges ...

and the North Lonsdale coast. The River Duddon and its estuary form part of the boundary of the historic county of Lancashire. It opens into the

Irish Sea The Irish Sea or , gv, Y Keayn Yernagh, sco, Erse Sie, gd, Muir Èireann , Ulster-Scots: ''Airish Sea'', cy, Môr Iwerddon . is an extensive body of water that separates the islands of Ireland and Great Britain. It is linked to the Ce ...

to the north of the Furness peninsula; Walney Island forming part of its southern edge. Its 28 miles (45 km) of shoreline enclose an area of 13 square miles (35 km²), making it the second largest estuary in Cumbria after the

Solway Firth The Solway Firth ( gd, Tràchd Romhra) is a firth that forms part of the border between England and Scotland, between Cumbria (including the Solway Plain) and Dumfries and Galloway. It stretches from St Bees Head, just south of Whitehaven in ...

and one of the six main estuaries in the historic county of Lancashire. The main settlements alongside the Duddon estuary are

Haverigg Haverigg is a village on the south-west coast of Cumbria, England, historically part of the county of Cumberland. In 2001 it had a population of 1,791 in 548 households, increasing in 2011 to a population of 1,849 in 549 Households. The name Ha ...

Millom Millom is a town and civil parish on the north shore of the estuary of the River Duddon in southwest Cumbria, historically part of Cumberland, England. It is situated just outside the Lake District National Park, about north of Barrow-in-Furne ...

, Foxfield,

Kirkby-in-Furness Kirkby-in-Furness, generally referred to simply as Kirkby locally, is a village in the Furness area of Cumbria, England. Historically part of Lancashire, it's located close to the Lake District National Park. It is about south of Broughton i ...

, Askam and Ireleth and

Barrow-in-Furness Barrow-in-Furness is a port town in Cumbria, England. Historically in Lancashire, it was incorporated as a municipal borough in 1867 and merged with Dalton-in-Furness Urban District in 1974 to form the Borough of Barrow-in-Furness. In 2023 the ...

Biological importance

The estuary as a whole was designated as a

Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of ...

(SSSI) in 1990 with the amalgamation of five previously separate SSSIs: Duddon Sands, Sandscale Haws, North Walney,

Hodbarrow Lagoon Hodbarrow RSPB Reserve is a nature reserve run by the Royal Society for the Protection of Birds on the edge of the Lake District National Park in Cumbria, England. It is on the Duddon Estuary near the town of Millom. History The nature reserve ...

and Haverigg Haws. It is a

Ramsar site A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention,8 ha (O) *** Permanent 8 ha (P) *** Seasonal Intermittent < 8 ha(Ts) **

natterjack toads. It supports one fifth of the national population of the rare amphibian that is only found at 50 sites in the UK, of which five are in the Duddon Estuary.

Birds

The Duddon Estuary is an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

. Species to be seen include pintail, red knot and common redshank with wintering waterfowl including

common shelduck The common shelduck (''Tadorna tadorna'') is a waterfowl species of the shelduck genus, ''Tadorna''. It is widespread and common in the Euro-Siberian region of the Palearctic, mainly breeding in temperate and wintering in subtropical regions; i ...

, red-breasted mergansers, Eurasian oystercatchers,

ringed plover The common ringed plover or ringed plover (''Charadrius hiaticula'') is a small plover that breeds in Arctic Eurasia. The genus name ''Charadrius'' is a Late Latin word for a yellowish bird mentioned in the fourth-century Vulgate. It derives from ...

dunlin The dunlin (''Calidris alpina'') is a small wader, formerly sometimes separated with the other "stints" in the genus ''Erolia''. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from ''dun'', "dull brown ...

and

Eurasian curlew The Eurasian curlew or common curlew (''Numenius arquata'') is a very large wader in the family Scolopacidae. It is one of the most widespread of the curlews, breeding across temperate Europe and Asia. In Europe, this species is often referred t ...

. In 1998 it was designated a Special Protection Area (SPA) under the Birds Directive. It qualified under three criteria: * regularly there are over 20,000 wintering waterfowl. * breeding population of

sandwich tern The Sandwich tern (''Thalasseus sandvicensis'') is a tern in the family Laridae. It is very closely related to the lesser crested tern (''T. bengalensis''), Chinese crested tern (''T. bernsteini''), Cabot's tern (''T. acuflavidus''), and elegan ...

s * overwintering populations of knot, pintail and redshank; populations on passage of ringed plover and sanderling. In 2015, before the

United Kingdom European Union membership referendum The United Kingdom European Union membership referendum, commonly referred to as the EU referendum or the Brexit referendum, took place on 23 June 2016 in the United Kingdom (UK) and Gibraltar to ask the electorate whether the country shoul ...

, there were consultations on a successful proposal that Morecambe Bay and Duddon Estuary be combined in a new SPA. This would amalgamate the existing Morecambe Bay and Duddon Estuary SPAs and would add marine areas identified as being used by foraging terns.

Flora

The estuary is botanically rich with

salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated ...

, sand dune and shingle communities, including a nationally rare shingle vegetation community at Haverigg Haws and North Walney. Shingle species include

sea sandwort ''Honckenya peploides'', the sea sandwort (UK) or seaside sandplant (Canada), is the only species in the genus ''Honckenya'' of the plant family Caryophyllaceae. Other common names include sea chickweed, sea pimpernal, sea-beach sandwort, and sea ...

, spear-leaved orache,

sea rocket ''Cakile'' is a genus within the flowering plant family Brassicaceae. Species in this genus are commonly known as searockets, though this name on its own is applied particularly to whatever member of the species is native or most common in the ...

and

sea kale ''Crambe maritima'', common name sea kale, seakale or crambe, is a species of halophytic (salt-tolerant) flowering plant in the genus ''Crambe'' of the family Brassicaceae. It grows wild along the coasts of mainland Europe and the British Isl ...

. All the dune grasslands at Sandscale Haws, Haverigg Haws and North Walney support a rich flora with the rare

dune helleborine ''Epipactis dunensis'', commonly known as dune helleborine, is a species of plant in the orchid family Orchidaceae and is endemic to Great Britain and Ireland. It typically grows to a height of and the upper half of the flowering stalk is hairy ...

Threats

Development has had no significant effect on the nature conservation interest of the estuary, but it is at risk from coastal defence works, grazing by agricultural stock,

sea level rise Globally, sea levels are rising due to human-caused climate change. Between 1901 and 2018, the globally averaged sea level rose by , or 1–2 mm per year on average.IPCC, 2019Summary for Policymakers InIPCC Special Report on the Ocean and Cry ...

, recreational pressure and bait digging.

References

External links

SPA designation
{{oscoor gbx, 319960_479880 Geography of Cumbria Important Bird Areas of England Ramsar sites in England Special Protection Areas in England Sites of Special Scientific Interest in Cumbria Furness Barrow-in-Furness