UK073
Thames Estuary and Marshes


IBA Justification

The site was identified as important in 2007 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.

Populations meeting IBA criteria ('trigger species'):
Species Red List Category Season Year(s) Population estimate at site IBA criteria met
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

The current IUCN Red List category (shown above) may differ from that which was valid at the time of IBA criteria assessment (2007).


IBA Conservation

IBA conservation assessment
Year of assessment (most recent) State (condition) Pressure (threat) Response (action)
2007 favourable medium low
Was the whole site assessed? State assessed by Accuracy of information
yes population good

State (condition of the trigger species' populations)
Scientific name Common name Reference population Actual population Units % of population 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

Pressure (threats to the trigger species and/or their habitats)
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

Response (conservation actions taken for the trigger species and/or their habitats)
Protected-area designation Management planning Other 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 conservation status, please click here

IBA Protection

Protected area (PA) PA designation PA area (ha) Relationship of PA with IBA Overlap of PA 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

Habitat (IUCN level 1) Habitat detail Extent (% of site)
Marine Intertidal -
Forest Broadleaved deciduous woodland, Mixed woodland -
Shrubland Scrub -
Grassland Humid grasslands -
Wetlands (inland) Water fringe vegetation -
Artificial/Terrestrial Arable land -
Marine Neritic -
Marine Coastal/Supratidal -
For more information about the IUCN Habitat classification, please click here.

Land use

Land-use Extent (% of site)
agriculture -
nature conservation and research -
urban/industrial/transport -


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Thames Estuary and Marshes. Downloaded from https://datazone.birdlife.org/site/factsheet/thames-estuary-and-marshes-iba-united-kingdom on 19/03/2024.