IBA Justification

The site was identified as important in 2000 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.

Populations meeting IBA criteria ('trigger species'):
Species Current IUCN Red List Category Season Year(s) Population estimate at site IBA criteria met
Pied Avocet Recurvirostra avosetta LC non-breeding 1988 1,500 individuals A4i, B1i, C2
Black-tailed Godwit Limosa limosa NT non-breeding 1985-1986 9,000 individuals A4i, B1i, C3
Ruff Calidris pugnax LC breeding 1988-1991 13 breeding pairs C6
Ruff Calidris pugnax LC non-breeding 1986 7,000 individuals C6
Common Tern Sterna hirundo LC breeding 1987-1991 1,680 breeding pairs C2, C6
A4iii Species group - waterbirds n/a unknown - 20,000 individuals A4iii, C4

The current IUCN Red List category may differ from that which was valid at the time of IBA criteria assessment (2000).

IBA Protection

Protected area (PA) PA designation PA area (ha) Relationship of PA with IBA Overlap of PA with IBA (ha)
Workumerwaard Ramsar Site, Wetland of International Importance 0 protected area overlaps with site 0
Friese IJsselmeerkust II Natural Monument 120 protected area overlaps with site 2
Friese IJsselmeerkust I Natural Monument 4,800 protected area overlaps with site 550


Habitat (IUCN level 1) Habitat detail Extent (% of site)
Wetlands (inland) Standing freshwater -
Artificial/Terrestrial Highly improved re-seeded landscapes -
For more information about the IUCN Habitat classification, please click here.

Land use

Land-use Extent (% of site)
agriculture -
other -
fisheries/aquaculture -
water management -
nature conservation and research -
tourism/recreation -

Recommended citation
BirdLife International (2023) Important Bird Area factsheet: Workumerwaard. Downloaded from on 01/10/2023.