UK073
Thames Estuary and Marshes


IBA Criteria

Year of most recent IBA criteria assessment: 2007

Populations of IBA trigger species
Species Current IUCN Red List Category Season Year(s) of estimate Population estimate IBA Criteria Triggered
Gadwall Mareca strepera LC winter 2001-2006 357 individuals B1i, C3
Pied Avocet Recurvirostra avosetta LC passage 2001-2006 649 individuals B2
Pied Avocet Recurvirostra avosetta LC winter 2001-2006 628 individuals B2, C6
Pied Avocet Recurvirostra avosetta LC breeding 1995 33 breeding pairs C6
Common Ringed Plover Charadrius hiaticula LC passage 2001-2006 737 individuals B1i, C3
Eurasian Curlew Numenius arquata NT passage 2001-2006 1,412 individuals B2
Eurasian Curlew Numenius arquata NT winter 2001-2006 1,495 individuals B2
Black-tailed Godwit Limosa limosa NT passage 2001-2006 3,299 individuals B1i, C3
Black-tailed Godwit Limosa limosa NT winter 2001-2006 1,247 individuals B1i, C3
Dunlin Calidris alpina LC passage 2001-2006 5,541 individuals B2
Dunlin Calidris alpina LC winter 2001-2006 15,181 individuals B1i, B2, C3
Common Redshank Tringa totanus LC winter 2001-2006 1,720 individuals B1i, C3
A4iii Species group - waterbirds n/a passage 2001-2006 24,702 individuals A4iii, C4
A4iii Species group - waterbirds n/a winter 2001-2006 47,805 individuals A4iii, C4

Note: This table presents the IBA criteria triggered and the species that triggered then at the time of assessment, the current IUCN Red List category may vary from that which was in place at that time.

For more information about the IBA assessment process and criteria please click here


IBA Monitoring

Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2007 medium favourable low
Was the whole site covered? Yes State assessed by Population
Accuracy of information good

Threats to the site (pressure)
Threat Level 1 Threat Level 2 Timing Scope Severity Result
Climate change and severe weather habitat shifting and alteration happening now small area/few individuals (<10%) slow but significant deterioration low
Energy production and mining renewable energy likely in short term (within 4 years) small area/few individuals (<10%) moderate to rapid deterioration low
Natural system modifications dams & water management/use - small dams likely in short term (within 4 years) some of area/population (10-49%) slow but significant deterioration medium
Natural system modifications other ecosystem modifications happening now small area/few individuals (<10%) slow but significant deterioration low
Pollution garbage & solid waste likely in short term (within 4 years) small area/few individuals (<10%) moderate to rapid deterioration low
Residential and commercial development commercial and industrial development likely in short term (within 4 years) small area/few individuals (<10%) moderate to rapid deterioration low
Transportation and service corridors roads and railroads likely in short term (within 4 years) small area/few individuals (<10%) moderate to rapid deterioration low
Transportation and service corridors shipping lanes likely in short term (within 4 years) small area/few individuals (<10%) moderate to rapid deterioration low

Condition of key/trigger populations (state)
Scientific Common TargetPop ActualPop Units Remaining Result
Mareca strepera Gadwall 130 357 individuals 100 favourable
Recurvirostra avosetta Pied Avocet 205 628 individuals 100 favourable
Charadrius hiaticula Common Ringed Plover 585 737 individuals 100 favourable
Numenius arquata Eurasian Curlew 1110 1495 individuals 100 favourable
Numenius arquata Eurasian Curlew 1160 1412 individuals 100 favourable
Limosa limosa Black-tailed Godwit 255 1247 individuals 100 favourable
Limosa limosa Black-tailed Godwit 515 3299 individuals 100 favourable
Calidris alpina Dunlin 12900 15181 individuals 100 favourable
Calidris alpina Dunlin 5650 5541 individuals 99 favourable
Tringa totanus Common Redshank 1890 1720 individuals 92 favourable
Tringa totanus Common Redshank 1680 1285 individuals 77 not assessed
Species group - waterbirds A4iii 36027 47805 individuals 100 favourable

Conservation actions taken at site (response)
Conservation Designation Management Planning Conservation Action Result
Most of site (50-90%) covered (including the most critical parts for important bird species) A management plan exists but it is out of date or not comprehensive Some limited conservation initiatives are in place low
For more information about IBA monitoring please click here

IBA Protection

Protected Area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)
West Thurrock Lagoon & Marshes Site of Special Scientific Interest (UK) 67 protected area overlaps with site 0
Vange & Fobbing Marshes Site of Special Scientific Interest (UK) 167 protected area is adjacent to site 0
Thames Estuary and Marshes Marine Protected Area (OSPAR) 0 protected area overlaps with site 0
Thames Estuary and Marshes Special Protection Area (Birds Directive) 4,802 protected area contained by site 4,839
Thames Estuary and Marshes Ramsar Site, Wetland of International Importance 5,589 protected area overlaps with site 5,589
South Thames Estuary and Marshes Site of Special Scientific Interest (UK) 5,289 protected area overlaps with site 5,355
South Essex Marshes Nature Reserve 736 protected area is adjacent to site 0
Shorne Marshes Nature Reserve 391 protected area overlaps with site 0
Rainham Marshes Nature Reserve 409 protected area contained by site 0
Rainham Marshes Local Nature Reserve 79 protected area overlaps with site 0
Northward Hill Nature Reserve 364 protected area overlaps with site 0
Mucking Flats and Marshes Site of Special Scientific Interest (UK) 313 protected area overlaps with site 0
Medway Estuary and Marshes Marine Protected Area (OSPAR) 0 protected area is adjacent to site 0
Medway Estuary and Marshes Special Protection Area (Birds Directive) 4,686 protected area is adjacent to site 0
Medway Estuary and Marshes Site of Special Scientific Interest (UK) 4,748 protected area is adjacent to site 0
Medway Estuary & Marshes Ramsar Site, Wetland of International Importance 4,697 protected area is adjacent to site 0
Medway Estuary Marine Conservation Zone 6,000 protected area overlaps with site 0
Medway Estuary Marine Protected Area (OSPAR) 5,800 protected area overlaps with site 0
Inner Thames Marshes Site of Special Scientific Interest (UK) 486 protected area overlaps with site 487
Holehaven Creek Site of Special Scientific Interest (UK) 273 protected area overlaps with site 0
Crossness Local Nature Reserve 26 protected area is adjacent to site 0
Cliffe Pools Nature Reserve 238 protected area overlaps with site 0
Canvey Wick Site of Special Scientific Interest (UK) 93 protected area is adjacent to site 0

Habitats

IUCN Habitat Habitat detail Extent (% of site)
Forest Broadleaved deciduous woodland, Mixed woodland -
Shrubland Scrub -
Grassland Humid grasslands -
Wetlands (inland) Tidal rivers and enclosed tidal waters, Mud flats and sand flats, Salt marshes, Coastal lagoons, Standing freshwater, Rivers and streams, Water fringe vegetation -
Artificial/Terrestrial Arable land -
For further information about the habitat classification please click here.

Land use

Land-use Extent (% of site)
agriculture -
nature conservation and research -
urban/industrial/transport -
For further information about the land use classification please click here.


Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Thames Estuary and Marshes. Downloaded from http://www.birdlife.org on 24/01/2022.