Exe Estuary

Site of Special Scientific Interest · 50.6425, -3.4435

Condition (Natural England)

Favourable (40) Unfavourable Declining (5) Unfavourable Recovering (1)
UnitFeatureConditionArea (ha)Assessed
SX940891 Favourable 9.06 2008-08-18
SX944888 Favourable 27.17 2008-08-18
SX944893 Favourable 28.75 2010-01-26
SX946888 Favourable 10.13 2008-08-18
SX947889 Favourable 28.75 2010-01-26
SX948885 Favourable 6.48 2008-08-18
SX950886 Favourable 3.82 2008-08-18
SX951881 Favourable 3.78 2008-08-18
SX953876 Favourable 43.3 2008-08-18
SX954871 Favourable 0.58 2008-08-18
SX954879 Unfavourable Declining 8.33 2015-01-27
SX955870 Favourable 2.82 2008-08-18
SX955882 Favourable 1.15 2008-08-18
SX955884 Favourable 8.92 2008-08-18
SX956875 Favourable 18.62 2008-08-18
SX957879 Favourable 21.04 2008-08-18
SX957885 Favourable 38.79 2009-07-15
SX958870 Favourable 36.41 2008-08-20
SX958881 Favourable 2.76 2009-08-03
SX959864 Favourable 15.5 2008-08-20
SX961873 Favourable 32.88 2008-08-18
SX962858 Favourable 23.34 2008-08-18
SX962863 Favourable 13.34 2008-08-18
SX963869 Favourable 18.86 2008-08-18
SX964853 Favourable 43.32 2008-08-18
SX966868 Favourable 75.77 2010-01-26
SX968873 Favourable 25.5 2024-02-29
SX970847 Favourable 11.77 2008-08-18
SX972860 Favourable 138.62 2024-03-04
SX972875 Favourable 17.17 2008-08-18
SX973849 Favourable 70.18 2024-03-04
SX973881 Favourable 5.54 2024-02-29
SX974879 Favourable 8.08 2009-08-03
SX975877 Favourable 6.33 2009-08-24
SX976866 Favourable 37.22 2024-03-04
SX977868 Favourable 16.29 2010-01-26
SX978827 Unfavourable Declining 135.67 2024-03-04
SX981809 Unfavourable Declining 90.13 2024-03-04
SX981849 Favourable 153.52 2024-03-04
SX982833 Favourable 98.26 2024-03-04
SX988806 Unfavourable Recovering 73.57 2024-03-04
SX988834 Unfavourable Declining 58.21 2024-03-04
SX991819 Unfavourable Declining 269.67 2024-03-04
SX995790 Favourable 335.78 2024-03-04
SY007798 Favourable 136.82 2024-03-04
SY020795 Favourable 6.89 2005-07-06

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Coastal

Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.

Habitats

Salt marsh

Geology & landscape

Geological Period: Carboniferous, Devonian, Permian

Landscape processes: Coastal, Fluvial

Birds & fish recorded

Birds

SpeciesSeason
Brent goose Wintering
avocet Breeding
avocet Wintering
black-tailed godwit Breeding
black-tailed godwit Wintering
oystercatcher Unknown
ringed plover Breeding
ringed plover Wintering
wigeon Breeding
wigeon Wintering

Description

Exe Estuary SSSI Description The waters, foreshore and low-lying land of the Exe Estuary are of international importance for wintering wildfowl and waders. Many rare species of plant occur too, whilst the sandbanks and mud flats support communities of invertebrates that are of national significance. The site also contains key features of geological interest and has been the subject of considerable scientific research. The Estuary runs south-eastward for about four kilometres from Exeter to the junction of the Exe and Clyst Rivers. Here it broadens, being over two kilometres wide in places, and runs for a further seven kilometres to Exmouth, where it is sheltered from the sea by the sand ridge of Dawlish Warren. The northern half of the estuary is flanked by reclaimed agricultural land, sewage works, reed beds and the Exeter Canal. The soil is alluvial, derived from a variety of Devonian, Carboniferous and Permian rocks. Over 10,000 wildfowl and 20,000 waders winter on the Estuary, which regularly supports over 1% of the European population of species such as dark-bellied Brent goose Branta bernicla bernicla, wigeon Mareca penelope, ringed plover Charadrius hiaticula and black-tailed godwit Limosa limosa. At about 250 birds, the flock of wintering avocets Recurvirostra avosetta is presently the largest in Britain. Reclaimed land within the site is used by water birds at high tide, and also provides nesting and feeding habitat for other bird species. The largest portion is the Exminster Marshes, a series of fields drained by dykes and ditches, which in turn carry a rich flora and fauna including several plants rare in Devon such as parsley water-dropwort Oenanthe lachenalii, flowering rush Butomus umbellatus and frog-bit Hydrocharis morsus-ranae, and a wide variety of dragonflies including the nationally uncommon ruddy darter Sympetrum sanguineum and hairy dragonfly Brachytron pratense. The Marshes are bounded by the Exeter Canal, and both the Canal and the Estuary in its upper reaches are fringed by beds mainly of common reed Phragmites australis which form an important area for several species of birds, notably warblers. Below the reedbeds there is a transition to saltmarsh. Here club-rushes Scripps spp. and sea rush Juncus maritimus are characteristic of the upper levels, with cord-grass Spartina spp. bordering these and increasing in extent lower down the Estuary. Below the saltmarshes and exposed at low tide, there are extensive areas of sand and mud. Some central banks are bare, and the remainder have only a sparse vegetation, but that vegetation consists largely of eelgrass Zostera spp. and green seaweed Enteromorpha spp., which are favoured foods of some wildfowl. Burrowing invertebrates are found in most of the sandbanks and mud flats, providing food for many fish and birds. Characteristic species include lugworm Arenicola marina, peppery furrow shell Scrobicularia plana, Tellins Macomb, Donax, Tellina, common cockle Cardium edule, razor shell Ensis siliqua, sea potato Echinocardium cordatum and masked crab Corystes cassivelaunus. Beds of mussels Mytilus edulis are important feeding grounds for oystercatchers Haematopus ostralegus. The Estuary is the only British locality for the polychaete worm Ophelia bicornia which occurs mainly on Bull Hill Bank. The foreshore rocks towards Orcombe Point are notable for the abundance of bivalve molluscs which bore into the soft sandstones. Here also occur colonies of the honeycomb worm Sabellaria alveolata. The Orcombe rocks are a key geological feature which display an excellent coastal section in the sandstones, siltstones and mudstones of the Permian Exmouth Formation. These fluvial sandstones show a variety of trough and planar-tabular cross-bedding indicating that the rivers which deposited these sediments flowed towards the north. Mudstones represent deposition in fluvial overbank (flood plain) and playa-like environments, and they contain rare plant fossils. This is an important site for the elucidation of Late Permian environments, and is also of general geomorphological importance for the study of sedimentation processes.

Species mentioned

English name
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Latin name
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IUCN / Red List Type Family
wigeon Mareca penelope LC (NonBreeding), NT (Breeding) bird-duck anatidae
Brent goose Branta bernicla LC (NonBreeding) bird-goose anatidae
ringed plover Charadrius hiaticula VU (NonBreeding) bird-wader charadriidae
oystercatcher Haematopus ostralegus LC (Breeding) bird-wader haematopodidae
black-tailed godwit Limosa limosa LC (NonBreeding) bird-wader scolopacidae
avocet Recurvirostra avosetta LC (NonBreeding), LC (Breeding) bird-wader recurvirostridae
blue mussel Mytilus edulis LC bivalve mytilidae
peppery furrow shell Scrobicularia plana Not listed in GB list bivalve semelidae
hairy dragonfly Brachytron pratense LC dragonfly aeshnidae
ruddy darter Sympetrum sanguineum LC dragonfly libellulidae
sea potato Echinocardium cordatum Not listed in GB list echinoderm loveniidae
common reed Phragmites australis LC grass poaceae
flowering rush Butomus umbellatus LC herb butomaceae
frogbit Hydrocharis morsus-ranae VU herb hydrocharitaceae
parsley water-dropwort Oenanthe lachenalii VU herb apiaceae
bivalve Ensis siliqua Not listed in GB list mollusc pharidae
blow lugworm Arenicola marina Not listed in GB list polychaete arenicolidae
honeycomb worm Sabellaria alveolata Not listed in GB list polychaete sabellariidae
sea rush Juncus maritimus LC rush juncaceae

Plant communities

SM1 — Salt marsh

Zostera communities

Zostera angustifolia, Zostera marina, Zostera noltei, Spartina anglica, Porphyra umbilicalis, Chondria dasyphylla, Polysiphonia nigra, Chara aspera, Chaetomorpha linum, Chaetomorpha tortuosa, Cladophora battersii, Cladophora retroflexa, Ulva intestinalis, Ulva lactuca, Fucus spiralis

SM2 — Salt marsh

Ruppia maritima salt-marsh community

Ruppia maritima

SM3 — Salt marsh

Eleocharis parvula salt-marsh community

Eleocharis parvula

SM4 — Salt marsh

Spartina maritima salt-marsh community

Suaeda maritima, Salicornia europaea, Salicornia perennis, Puccinellia maritima, Spartina anglica, Spartina maritima

SM5 — Salt marsh

Spartina alterniflora salt-marsh community

Puccinellia maritima, Spartina alterniflora, Spartina anglica

SM6 — Salt marsh

Spartina anglica salt-marsh community

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Cochlearia anglica, Spergularia media, Atriplex hastata, Salicornia europaea, Plantago maritima, Limonium vulgare, Puccinellia maritima, Spartina anglica, Catenella caespitosa, Fucus vesiculosus, Fucus vesiculosus ecad volubilis

SM7 — Salt marsh

Arthrocnemum perenne stands

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Spergularia media, Salicornia europaea, Salicornia perennis, Limonium vulgare, Puccinellia maritima, Bostrychia scorpioides

SM8 — Salt marsh

Annual Salicornia salt-marsh community

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Salicornia europaea, Puccinellia maritima, Spartina anglica

SM9 — Salt marsh

Suaeda maritima salt-marsh community

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Salicornia europaea, Puccinellia maritima, Spartina anglica

SM10 — Salt marsh

Transitional low-marsh vegetation with Puccinellia maritima annual Salicornia species and Suaeda maritima

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Spergularia media, Salicornia europaea, Triglochin maritimum, Armeria maritima, Limonium vulgare, Puccinellia maritima, Spartina anglica

SM11 — Salt marsh

Aster tripolium var. discoideus salt-marsh community

Atriplex portulacoides, Suaeda maritima, Aster tripolium, Spergularia media, Salicornia europaea, Salicornia perennis, Plantago maritima, Puccinellia maritima, Spartina anglica, Bostrychia scorpioides, Fucus vesiculosus, Pelvetia canaliculata

SM12 — Salt marsh

Rayed Aster Tripolium on slat marshes

Schoenoplectus lacustris, Juncus bufonius, Suaeda maritima, Aster tripolium, Spergularia marina, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago maritima, Puccinellia distans, Puccinellia maritima, Spartina anglica

SM13 — Salt marsh

Puccinellia maritima salt-marsh community

Atriplex portulacoides, Juncus gerardii, Suaeda maritima, Aster tripolium, Cochlearia anglica, Cochlearia officinalis, Spergularia media, Atriplex hastata, Salicornia europaea, Salicornia perennis, Triglochin maritimum, Plantago maritima, Armeria maritima, Limonium humile, Limonium vulgare, Glaux maritima, Agrostis stolonifera, Festuca rubra, Puccinellia maritima, Spartina anglica, Spartina maritima, Bostrychia scorpioides, Fucus cottonii

SM14 — Salt marsh

Halimione portulacoides salt-marsh community

Atriplex portulacoides, Juncus maritimus, Suaeda maritima, Artemisia maritima, Aster tripolium, Inula crithmoides, Spergularia media, Salicornia europaea, Salicornia perennis, Triglochin maritimum, Plantago maritima, Armeria maritima, Limonium vulgare, Elytrigia atherica, Puccinellia maritima, Spartina anglica

SM15 — Salt marsh

Juncus maritimus-Triglochin maritima salt-marsh community

Atriplex portulacoides, Carex extensa, Juncus gerardii, Juncus maritimus, Suaeda maritima, Oenanthe lachenalii, Artemisia maritima, Cochlearia anglica, Cochlearia officinalis, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago maritima, Armeria maritima, Limonium humile, Limonium vulgare, Glaux maritima, Agrostis stolonifera, Festuca rubra, Phragmites australis, Puccinellia maritima, Spartina anglica, Fucus cottonii

SM16 — Salt marsh

Festuca rubra salt-marsh community

Atriplex portulacoides, Carex distans, Carex flacca, Juncus gerardii, Hypnum cupressiforme, Kindbergia praelonga, Rhytidiadelphus squarrosus, Scorzoneroides autumnalis, Cochlearia anglica, Cerastium fontanum, Sagina procumbens, Spergularia media, Atriplex hastata, Salicornia europaea, Lotus corniculatus, Trifolium repens, Triglochin maritimum, Plantago lanceolata, Plantago maritima, Armeria maritima, Limonium vulgare, Glaux maritima, Ranunculus acris, Potentilla anserina, Agrostis stolonifera, Anthoxanthum odoratum, Cynosurus cristatus, Festuca rubra, Holcus lanatus, Puccinellia maritima

SM17 — Salt marsh

Artemisia maritima salt-marsh community

Atriplex portulacoides, Juncus gerardii, Juncus maritimus, Suaeda maritima, Suaeda vera, Artemisia maritima, Cochlearia anglica, Cochlearia officinalis, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago coronopus, Plantago maritima, Armeria maritima, Limonium vulgare, Glaux maritima, Agrostis stolonifera, Elytrigia atherica, Elytrigia repens, Festuca rubra, Hordeum marinum, Parapholis strigosa, Puccinellia maritima

SM18 — Salt marsh

Juncus maritimus salt-marsh community

Carex distans, Carex extensa, Carex otrubae, Juncus gerardii, Juncus maritimus, Amblystegium serpens, Kindbergia praelonga, Oenanthe lachenalii, Cirsium arvense, Scorzoneroides autumnalis, Sonchus arvensis, Cochlearia officinalis, Silene flos-cuculi, Atriplex hastata, Lotus corniculatus, Trifolium repens, Vicia cracca, Triglochin maritimum, Plantago maritima, Armeria maritima, Rumex crispus, Glaux maritima, Samolus valerandi, Ranunculus acris, Potentilla anserina, Galium palustre, Agrostis stolonifera, Elytrigia repens, Festuca rubra, Holcus lanatus, Poa pratensis, Schedonorus arundinaceus

SM19 — Saline lagoon, Salt marsh

Blysmus rufus salt-marsh community

Blysmus rufus, Carex extensa, Carex lepidocarpa, Carex nigra, Eleocharis quinqueflora, Eleocharis uniglumis, Juncus articulatus, Juncus gerardii, Amblystegium serpens, Calliergonell cuspidatum, Drepanocladus polygamus, Leptodictyum riparium, Oenanthe lachenalii, Scorzoneroides autumnalis, Cochlearia anglica, Trifolium repens, Triglochin maritimum, Triglochin palustre, Plantago maritima, Armeria maritima, Glaux maritima, Potentilla anserina, Agrostis stolonifera, Alopecurus geniculatus, Festuca rubra, Puccinellia maritima

SM20 — Saline lagoon, Salt marsh

Eleocharis uniglumis salt-marsh community

Bolboschoenus maritimus, Carex distans, Carex extensa, Carex nigra, Eleocharis quinqueflora, Eleocharis uniglumis, Juncus articulatus, Juncus gerardii, Leptodictyum riparium, Oenanthe lachenalii, Hydrocotyle vulgaris, Scorzoneroides autumnalis, Atriplex hastata, Trifolium repens, Triglochin maritimum, Triglochin palustre, Plantago maritima, Armeria maritima, Glaux maritima, Samolus valerandi, Potentilla anserina, Galium palustre, Agrostis stolonifera, Alopecurus geniculatus, Festuca rubra

SM21 — Salt marsh

Suaeda vera-Limonium binervosum salt-marsh community

Atriplex portulacoides, Frankenia laevis, Suaeda maritima, Suaeda vera, Artemisia maritima, Cochlearia anglica, Cochlearia danica, Cochlearia officinalis, Sagina maritima, Spergularia marina, Spergularia media, Salicornia europaea, Plantago maritima, Armeria maritima, Limonium bellidifolium, Limonium binervosum, Limonium vulgare, Glaux maritima, Elytrigia atherica, Festuca rubra, Puccinellia maritima

SM22 — Salt marsh

Halimione portulacoides-Frankenia laevis salt-marsh community

Atriplex portulacoides, Frankenia laevis, Suaeda maritima, Spergularia media, Salicornia europaea, Salicornia perennis, Plantago coronopus, Plantago maritima, Armeria maritima, Limonium vulgare, Elytrigia juncea, Festuca rubra, Parapholis strigosa, Puccinellia maritima

SM23 — Salt marsh

Spergularia marina-Puccinellia distans salt-marsh community

Atriplex portulacoides, Juncus bufonius, Suaeda maritima, Spergularia marina, Spergularia media, Atriplex hastata, Salicornia europaea, Triglochin maritimum, Plantago maritima, Polygonum aviculare, Glaux maritima, Agrostis stolonifera, Alopecurus geniculatus, Elytrigia atherica, Festuca rubra, Parapholis strigosa, Puccinellia distans, Puccinellia maritima

SM24 — Salt marsh

Elymus pycnanthus salt-marsh community

Atriplex portulacoides, Juncus gerardii, Juncus maritimus, Hypnum cupressiforme, Suaeda vera, Artemisia maritima, Aster tripolium, Sonchus arvensis, Atriplex hastata, Atriplex littoralis, Beta vulgaris sp maritima, Plantago maritima, Armeria maritima, Limonium vulgare, Glaux maritima, Potentilla anserina, Galium aparine, Agrostis stolonifera, Ammophila arenaria, Elytrigia atherica, Festuca rubra, Parapholis strigosa, Phragmites australis, Puccinellia maritima

SM25 — Salt marsh

Suaeda vera drift-line community

Atriplex portulacoides, Suaeda maritima, Suaeda vera, Artemisia maritima, Cochlearia anglica, Cochlearia danica, Cochlearia officinalis, Spergularia media, Atriplex littoralis, Salicornia europaea, Salicornia perennis, Triglochin maritimum, Plantago maritima, Limonium vulgare, Glaux maritima, Elytrigia atherica, Festuca rubra, Puccinellia maritima, Bostrychia scorpioides, Pelvetia canaliculata

SM26 — Salt marsh

Inula crithmoides stands

Atriplex portulacoides, Suaeda maritima, Inula crithmoides, Spergularia media, Salicornia europaea, Salicornia perennis, Plantago maritima, Armeria maritima, Limonium vulgare, Elytrigia atherica, Festuca rubra, Puccinellia maritima, Spartina anglica, Bostrychia scorpioides

SM28 — Salt marsh

Elymus repens salt-marsh community

Bolboschoenus maritimus, Carex otrubae, Eleocharis uniglumis, Juncus gerardii, Kindbergia praelonga, Odontites verna, Anthriscus sylvestris, Apium graveolens, Heracleum sphondylium, Oenanthe crocata, Oenanthe lachenalii, Torilis japonica, Centaurea nigra, Cirsium arvense, Cirsium vulgare, Scorzoneroides autumnalis, Sonchus arvensis, Tripleurospermum maritimum, Cochlearia anglica, Cochlearia officinalis, Silene uniflora, Stellaria media agg., Atriplex hastata, Atriplex littoralis, Calystegia sepium, Lotus corniculatus, Medicago lupulina, Melilotus altissima, Trifolium repens, Vicia cracca, Triglochin maritimum, Plantago lanceolata, Plantago maritima, Rumex conglomeratus, Rumex crispus, Glaux maritima, Potentilla anserina, Galium aparine, Urtica dioica, Agrostis stolonifera, Alopecurus geniculatus, Arrhenatherum elatius, Dactylis glomerata, Deschampsia cespitosa, Elytrigia repens, Festuca rubra, Holcus lanatus, Lolium perenne, Poa pratensis, Puccinellia maritima, Schedonorus arundinaceus