Adur Estuary

Site of Special Scientific Interest · 50.8468, -0.2868

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West Sussex County SOUTH DOWNS National Park

Condition (Natural England)

Unfavourable Declining (7) Favourable (1)
UnitFeatureConditionArea (ha)Assessed
TQ205059 — Unfavourable Declining 35.91 2021-02-15
TQ206055 — Unfavourable Declining 8.53 2021-02-15
TQ206058 — Favourable 15.31 2008-10-23
TQ206061 — Unfavourable Declining 35.91 2021-02-15
TQ207066 — Unfavourable Declining 0.5 2021-03-09
TQ209054 — Unfavourable Declining 35.91 2021-02-15
TQ211048 — Unfavourable Declining 8.53 2021-02-15
TQ212047 — Unfavourable Declining 35.91 2021-02-15

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

Reedbed, Salt marsh

Geology & landscape

Landscape processes: Coastal

Birds & fish recorded

Birds

SpeciesSeason
dunlin Breeding
redshank Breeding
reed warbler Breeding
ringed plover Breeding
sedge warbler Breeding

Description

Area, 62.2 ha. 153.6 ac. Description The Adur Estuary, together with Rye Harbour further to the east, represent the only significant areas of saltmarsh between Chichester and Pagham Harbours in West Sussex and Sandwich Bay in Kent, The estuarine plant communities are unusual due to the relative scarcity of cord grass, Spartina spp. The large area of intertidal mud flats within the estuary are important for a variety of wading birds. Saltmarsh plants fringe most of the estuary and in places have colonised large areas of mud flats. Sea purslane Halimione portaculoides dominates most of the areas above mean high water mark and annual seablite Suaeda maritima is also extremely frequent in these areas. Towards the mean low water mark, glasswort Salicornia sp. is dominant and sea aster Aster tripolium becomes more abundant. Other species are scattered throughout the saltmarsh community, including common sea lavender Limonium vulgare, thrift Armeria maritima, sea plantain Plantago maritima and sea poa grass, Puccinellia maritima. Cordgrass Spartina spp. is noticeably absent from most of the estuary, but a small stand does grow southeast of the Old Shoreham Bridge. At the landward margin of the saltmarsh a variety of herbs and shrubs are frequent, including mugwort Artemisia vulgaris, orache Atriplex spp., teasel Dipsacus fullonum, yarrow Achillea millefolium and elm Ulmus procera. The intertidal mud flats of the Adur Estuary support a number of wading birds, particularly redshank, dunlin and ringed plover. The number of ringed plover regularly exceed one percent of the total British population, making the estuary of national importance for this species. A variety of species breed within the reedbed adjacent to the estuary north of the A27, including moorhen, reed warbler and sedge warbler. The estuary embankment near the car park supports a large colony of viviparous lizards, Lacerta agilis.

Species mentioned

English name
search for this in other sites		 Latin name
search with Google		 IUCN / Red List Type Family
moorhen Gallinula chloropus VU (Breeding) bird-gallinule rallidae
dunlin Calidris alpina EN (NonBreeding) bird-wader scolopacidae
ringed plover Charadrius hiaticula VU (NonBreeding) bird-wader charadriidae
redshank Tringa totanus EN (NonBreeding) bird-wader scolopacidae
sedge warbler Acrocephalus schoenobaenus LC (Breeding) bird-warbler acrocephalidae
reed warbler Acrocephalus scirpaceus LC (Breeding) bird-warbler acrocephalidae
saltmarsh grass Puccinellia maritima LC grass poaceae
yarrow Achillea millefolium LC herb asteraceae
thrift Armeria maritima CR herb plumbaginaceae
mugwort Artemisia vulgaris LC herb asteraceae
sea aster Aster tripolium Not listed in GB list herb asteraceae
teasel Dipsacus fullonum LC herb dipsacaceae
common sea lavender Limonium vulgare NT herb plumbaginaceae
sea plantain Plantago maritima LC herb plantaginaceae
common seablite Suaeda maritima LC herb amaranthaceae
sand lizard Lacerta agilis EN reptile lacertidae
English elm Ulmus procera LC tree ulmaceae

Plant communities

S4 — Lowland fen, Nutrient rich eutrophic lake, Reedbed

Phragmites australis swamp and reed-beds

Salix cinerea, Atriplex portulacoides, Solanum dulcamara, Bolboschoenus maritimus, Carex acuta, Carex lasiocarpa, Carex otrubae, Carex panicea, Carex pseudocyperus, Carex riparia, Carex rostrata, Cladium mariscus, Eriophorum angustifolium, Eleocharis palustris, Juncus articulatus, Juncus bulbosus, Juncus effusus, Juncus gerardii, Juncus maritimus, Juncus subnodulosus, Sparganium erectum, Sparganium minimum, Brachythecium rutabulum, Calliergonell cuspidatum, Leptodictyum riparium, Sphagnum fallax, Suaeda maritima, Angelica sylvestris, Apium graveolens, Berula erecta, Cicuta virosa, Oenanthe crocata, Oenanthe fistulosa, Oenanthe lachenalii, Sium latifolium, Hydrocotyle vulgaris, Sonchus arvensis, Tripleurospermum maritimum, Myosotis laxa, Myosotis scorpioides, Cardamine pratensis, Cochlearia anglica, Cochlearia officinalis, Silene flos-cuculi, Atriplex hastata, Atriplex littoralis, Salicornia dolichostachya, Calystegia sepium, Equisetum fluviatile, Equisetum palustre, Lotus pedunculatus, Iris pseudacorus, Triglochin maritimum, Lycopus europaeus, Mentha aquatica, Lemna minor, Utricularia intermedia, Utricularia minor, Lythrum salicaria, Menyanthes trifoliata, Nymphaea alba, Epilobium hirsutum, Callitriche stagnalis, Hippuris vulgaris, Plantago maritima, Armeria maritima, Limonium vulgare, Rumex crispus, Rumex hydrolapathum, Potamogeton gramineus, Potamogeton natans, Potamogeton polygonifolius, Glaux maritima, Ranunculus flammula, Ranunculus lingua, Ranunculus sceleratus, Comarum palustre, Filipendula ulmaria, Rubus fruticosus agg., Galium aparine, Galium palustre, Galium uliginosum, Urtica dioica, Agrostis stolonifera, Elytrigia atherica, Elytrigia repens, Festuca rubra, Glyceria fluitans, Glyceria maxima, Holcus lanatus, Molinia caerulea, Phalaris arundinacea, Phragmites australis, Poa trivialis, Puccinellia maritima, Typha angustifolia, Typha latifolia, Chara subspinosa

S25 — Lowland fen, Reedbed

Phragmites australis-Eupatorium cannabinum tall-herb fen

Salix cinerea, Alnus glutinosa, Myrica gale, Solanum dulcamara, Carex acuta, Carex elata, Carex paniculata, Carex riparia, Cladium mariscus, Juncus subnodulosus, Brachythecium rutabulum, Calliergonell cuspidatum, Lophocolea bidentata, Angelica sylvestris, Berula erecta, Oenanthe lachenalii, Hydrocotyle vulgaris, Caltha palustris, Cirsium palustre, Eupatorium cannabinum, Myosotis scorpioides, Valeriana dioica, Valeriana officinalis, Silene flos-cuculi, Calystegia sepium, Equisetum fluviatile, Equisetum palustre, Lathyrus pratensis, Lotus pedunculatus, Vicia cracca, Iris pseudacorus, Lycopus europaeus, Mentha aquatica, Lythrum salicaria, Menyanthes trifoliata, Epilobium hirsutum, Pedicularis palustris, Rumex crispus, Comarum palustre, Filipendula ulmaria, Rubus fruticosus agg., Galium aparine, Galium palustre, Galium uliginosum, Scrophularia auriculata, Scutellaria galericulata, Urtica dioica, Arrhenatherum elatius, Phalaris arundinacea, Phragmites australis, Thelypteris palustris, Athyrium filix-femina, Typha angustifolia

S26 — Lowland fen, Reedbed

Phragmites australis-Urtica dioica tall-herb fen

Solanum dulcamara, Carex acuta, Carex otrubae, Carex riparia, Juncus effusus, Juncus subnodulosus, Sparganium erectum, Brachythecium rutabulum, Kindbergia praelonga, Angelica sylvestris, Apium nodiflorum, Heracleum sphondylium, Oenanthe crocata, Cirsium arvense, Cirsium palustre, Eupatorium cannabinum, Pulicaria dysenterica, Sonchus arvensis, Myosotis scorpioides, Valeriana officinalis, Silene dioica, Silene flos-cuculi, Calystegia sepium, Dipsacus fullonum, Equisetum fluviatile, Equisetum palustre, Lathyrus pratensis, Lotus pedunculatus, Vicia cracca, Iris pseudacorus, Glechoma hederacea, Lycopus europaeus, Mentha aquatica, Stachys palustris, Lythrum salicaria, Epilobium hirsutum, Rumex crispus, Rumex hydrolapathum, Lysimachia vulgaris, Ranunculus acris, Ranunculus repens, Filipendula ulmaria, Potentilla anserina, Rubus fruticosus agg., Galium aparine, Galium palustre, Galium uliginosum, Scutellaria galericulata, Urtica dioica, Agrostis stolonifera, Arrhenatherum elatius, Dactylis glomerata, Elytrigia repens, Glyceria maxima, Holcus lanatus, Phalaris arundinacea, Phragmites australis, Poa trivialis, Schedonorus arundinaceus, Typha latifolia

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