SPA description
(information as published 2001)

Severn Estuary

image: SPA location map 

 

The Severn Estuary is located between Wales and England in south-west Britain. It is a large estuary with extensive intertidal mud-flats and sand-flats, rocky platforms and islands. Saltmarsh fringes the coast backed by grazing marsh with freshwater ditches and occasional brackish ditches. The seabed is rock and gravel with sub-tidal sandbanks. The estuary's classic funnel shape, unique in the UK, is a factor causing the Severn to have the second- highest tidal range in the world (after the Bay of Fundy in Canada). This tidal regime results in plant and animal communities typical of the extreme physical conditions of liquid mud and tide- swept sand and rock. The species-poor invertebrate community includes high densities of ragworms, lugworms and other invertebrates forming an important food source for passage and wintering waders. A further consequence of the large tidal range is an extensive intertidal zone, one of the largest in the UK. The site is of importance during the spring and autumn migration periods for waders moving up the west coast of Britain, as well as in winter for large numbers of waterbirds, especially swans, ducks and waders. 
 
For more information see Phased, extended and subsumed SPAs

 


Qualifying species

For individual species accounts visit the Species Accounts section


This site qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting populations of European importance of the following species listed on Annex I of the Directive:
 
Over winter;
 
Bewick's Swan Cygnus columbianus bewickii, 280 individuals representing at least 4.0% of the wintering population in Great Britain (5 year peak mean 1991/2 - 1995/6)
 
This site also qualifies under Article 4.2 of the Directive (79/409/EEC) by supporting populations of European importance of the following migratory species:
 
On passage;
 
Ringed Plover Charadrius hiaticula, 655 individuals representing at least 1.3% of the Europe/Northern Africa - wintering population (5 year peak mean 1991/2 - 1995/6)
 
Over winter;
 
Curlew Numenius arquata, 3,903 individuals representing at least 1.1% of the wintering Europe - breeding population (5 year peak mean 1991/2 - 1995/6)
 
Dunlin Calidris alpina alpina, 44,624 individuals representing at least 3.2% of the wintering Northern Siberia/Europe/Western Africa population (5 year peak mean 1991/2 - 1995/6)
 
Pintail Anas acuta, 599 individuals representing at least 1.0% of the wintering Northwestern Europe population (5 year peak mean 1991/2 - 1995/6)
 
Redshank Tringa totanus, 2,330 individuals representing at least 1.6% of the wintering Eastern Atlantic - wintering population (5 year peak mean 1991/2 - 1995/6)
 
Shelduck Tadorna tadorna, 3,330 individuals representing at least 1.1% of the wintering Northwestern Europe population (5 year peak mean 1991/2 - 1995/6)
 
Assemblage qualification: A wetland of international importance.
 
The area qualifies under Article 4.2 of the Directive (79/409/EEC) by regularly supporting at least 20,000 waterfowl
 
Over winter, the area regularly supports 93,986 individual waterfowl (5 year peak mean 1991/2 - 1995/6) including: Gadwall Anas strepera, Shelduck Tadorna tadorna, Pintail Anas acuta, Dunlin Calidris alpina alpina, Curlew Numenius arquata, Redshank Tringa totanus, Bewick's Swan Cygnus columbianus bewickii, Wigeon Anas penelope, Lapwing Vanellus vanellus, Teal Anas crecca, Mallard Anas platyrhynchos, Shoveler Anas clypeata, Pochard Aythya ferina, Tufted Duck Aythya fuligula, Grey Plover Pluvialis squatarola, White-fronted Goose Anser albifrons albifrons , Whimbrel Numenius phaeopus.

 


Note:

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.
 
Note that sites selected for waterbird species on the basis of their occurrence in the breeding, passage or winter periods also provide legal protection for these species when they occur at other times of the year.