Key Biodiversity Areas

Severn Estuary (2591)
United Kingdom, Europe

Site overview


KBA status: confirmed
Year of last assessment: 2007
National site name: Severn Estuary
Central coordinates: Latitude: 51.5902, Longitude: -2.6777
System: marine, terrestrial
Elevation (m): 0 to 78
Area of KBA (km2): 252.29625
Protected area coverage (%): 99.49
KBA classification: Regional
Legacy site: Yes

Site details


Site description: The estuary is fed by five major rivers (the Severn, Wye, Usk, Parrett and Avon) in addition to other lesser rivers. Classically funnel-shaped, the estuary has the second widest tidal range in the world and is characterized by strong currents, mobile sediments and high turbidity. Large expanses of cord-grass Spartina occur. The site supports internationally important numbers of wintering and passage wildfowl and waders, in addition to important breeding bird populations.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that was identified using previously established criteria and thresholds for the identification of Important Bird and Biodiversity Areas (IBAs) and for which available data indicate that it does not meet global KBA criteria and thresholds set out in the Global Standard.
Delineation rationale: First identified in 1989; small changes to boundary in 1992 and 2000; further changes in 2007, including small additions and the deletion of Cardiff Bay. 2000 area, 59950 included large marine areas incorrectly. SPA boundary used from JNCC; digitised at 1:10,000 scale. Additional area added on 1:50,000 maps.

Habitats


Land use: fisheries/aquaculture | nature conservation and research | tourism/recreation | urban/industrial/transport | water management
IUCN HabitatCoverage %Habitat detail
Shrubland5
Forest5
Marine Intertidal40
Marine Neritic40
Grassland5
Marine Coastal/Supratidal5

Threats


Threat level 1Threat level 2Threat level 3Timing
Biological resource useFishing & harvesting aquatic resourcesUnintentional effects: large scale (species being assessed is not the target) [harvest]Ongoing
Energy production & miningRenewable energyOnly in the future
Climate change & severe weatherHabitat shifting & alterationOnly in the future
Human intrusions & disturbanceRecreational activitiesOnly in the future
Natural system modificationsOther ecosystem modificationsOngoing
Residential & commercial developmentTourism & recreation areasOnly in the future
Transportation & service corridorsShipping lanesOnly in the future