Tweed Catchment Rivers - England: Lower Tweed and Whiteadder

Also within

Berwickshire CountyNorthumberland CountyRoxburgh, Ettrick and Lauderdale County King Charles Way - Bamburgh to Scottish Border inc Holy Island National Trail

Condition (Natural England)

Climate exposure

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

Habitats

Fast flowing river and stream

Geology & landscape

Rock Type: Sandstone

Landscape processes: Coastal, Glacial

Birds & fish recorded

Birds

Fish

Description

Description The site is of international importance for its estuary, intertidal mud and sand flats and its riverine floating vegetation communities often dominated by water crowfoot Ranunculus species. It also supports internationally important populations of river lamprey Lampetra fluviatilis, sea lamprey Petromyzon marinas, Atlantic salmon Salmo salar and common otter Lutra lutra. The lower reaches of the Tweed and Whiteadder are nationally important examples of lowland rivers with minimal gradients in England and rivers on rich geological strata in Scotland and northern England. The exposed river sediments are nationally important for their invertebrate assemblage. The site holds nationally important populations of wintering goldeneye Bucephala clangula and moulting mute swans Cygnus olor. The Lower Tweed and Whiteadder comprise the lower sections of the Tweed catchment rivers within England. The River Tweed is 160 kilometres long from its source at Tweed’s Well in Scotland to the mouth at Berwick upon Tweed. Within the site, the English section of the Tweed flows 32 kilometres from the national boundary at Carham Wiel to the confluence of the Whiteadder Water. A further three kilometres comprises the English section of the Whiteadder Water, whilst the estuary occupies an additional 5 km. The fish fauna of the river is one of the richest in great Britain and the river supports one of the most important game fisheries in England. The river supports significant populations of Atlantic salmon with large seasonal migrations, one run in the spring and a larger one in the autumn. Two species of lamprey; river lampreys and sea lamprey are found in the SSSI. The rare allis shad Alosa alosa has been recorded in breeding condition. Other species found in the river system include sea trout Salmo trutta trutta, brown trout Salmo trutta, eel Anguilla anguilla, stone loach Barbatula barbatula, minnow Phoxinus phoxinus, three spined stickleback Gasterosteus aculeatus, pike Esox lucius, grayling Thymallus thymallus and dace Leuciscus leuciscus. Insects associated with the river and riverside margins include a high diversity of species. Particularly abundant groups include mayflies, caddis flies and stoneflies. The exposed river sediments are an important habitat for invertebrates and several nationally scarce beetles and flies are found, riverine ground beetles Bembidion bipunctatum, B. littorale, B. schueppeli and Trechus rubens; root feeding weevils Omiamima mollina and Glocianus punctiger; the sorrel leaf beetle, Mantura chrysanthemi; a click beetle Oedostethus quadripustulatus; a water beetle Helophorus arvernicus; rove beetles Liocyrtusa minuta, Gabrius bishopi and Stenus niveus and the dolly fly Rhaphium fascipes. The River Tweed is also an important habitat for common otter L. lutra which have successfully recolonised the river and are now found throughout the catchment and in the estuary. In late summer the estuary holds a nationally significant flock of moulting mute swans. In winter goldeneye occur in nationally significant numbers in the estuary and lower river. Other species that occur include heron Ardea cinerea, goosander Mergus merganser and cormorant Phalacrocorax carbo. The estuary attracts a variety of waders and wildfowl including eider Somateria mollissima, mallard Anas platyrhynchos, dunlin Calidris alpina, oystercatcher Haematopus ostralegus, curlew Numenius arquata, redshank Tringa totanus and turnstone Arenaria interpres. The component rivers have an aquatic flora characteristic of large rivers on old red sandstone. M osses and other lower plant species are scarce, although a rare lichen Verrucaria praetermissa is found, usually on submerged siliceous rocks, within the River Tweed. The Ranunculus beds of the lower Tweed are an internationally important habitat, species characteristic of large rivers are found here including river water crowfoot Ranunculus fluitans and brook water crowfoot Ranunculus penicillatus subsp. pseudofluitans. The presence of curled pondweed Potamogeton crispus, fennel pondweed Potamogeton pectinatus and perfoliate pondweed Potamogeton perfoliatus, indicate the base rich nature of the rivers. Nationally scarce plants include the graceful pondweed P. xolivaceus and the willow leaved pondweed P. x salicifolius, natural hybrids for which the River Tweed is one of the strongholds in great Britain. Vegetation of the river margins include the uncommon green figwort Scrophularia umbrosa and sand leek Allium scorodoprasum found along the Lower Tweed. The river margins are dominated in places by tall emergent plants such as reed canary grass Phalaris arundinacea. Other waterside plants include water mint Mentha aquatica, waterforget-me-not Myosotis scorpioides, floating sweet grass Glyceria fluitans, creeping yellow cress Rorippa sylvestris, brooklime Veronica beccabunga and branched burreed Sparganium erectum, many of which are typical of base rich rivers. Other Information This site is an enlargement of the Tweed Estuary SSSI, previously notified under the Wildlife and Countryside Act 1981 as amended. Part of this site encompasses the Tweed Estuary candidate Special Area of Conservation SAC and all other areas comprise part of the River Tweed as recommended as a possible SAC containing habitat types and species which are rare or threatened within a European context. This site supports the following habitats listed in Annex 1 of the EC Habitats and Species Directive 92/43/ EEC,···floating vegetation of Ranunculus of plain and submontainous rivers; estuaries; mud flats and sandflats not covered by seawater at low tide. Of the species for which this site is notified, Annexes IIa, at maa and Va of the EC Habitats and Species Directive 92/43/ EEC and Schedule 2 of The Conservation Natural Habitats and c Regulations 1994 list the following as specially protected, common otter II and at maa, salmon and river lamprey IIa, Va and sea lamprey IIa. Common otter is also protected under Schedule 5 of the Wildlife and Countryside Act 1981. At Tillmouth, the SSSI abuts The Tweed Catchment Rivers England, Till Catchment SSSI, notified in November 1999. To the north and south of the estuary the site abuts but forms a separate notification to the Northumberland Shore SSSI, notified in 1992. The Tweed Catchment Rivers England, lower Tweed and Whiteadder SSSI also abuts the River Tweed SSSI notified in Scotland under the Wildlife and Countryside Citation, the Tweed Catchment Rivers England, Lower Tweed and Whiteadder SSSI Act 1981. Notifications in Scotland are not subject to the amendments made by the Countryside and Rights of Way Act 2000 to the Wildlife and Countryside Act 1981. Citation, the Tweed Catchment Rivers England, Lower Tweed and Whiteadder SSSI

Species mentioned

Plant communities