Lake IJsselmeer (1215)
Netherlands, Europe
Site overview
KBA status: confirmed
Global KBA criteria: A1d, D1a
Year of last assessment: 2016
National site name: IJsselmeer
Central coordinates: Latitude: 52.7500, Longitude: 5.4500
System: marine, terrestrial
Elevation (m): -6 to -2
Area of KBA (km2): 1133.53347
Protected area coverage (%): 100.00
KBA classification: Global
Legacy site: Yes
Site details
Site description: Previously the Zuiderzee, this area is now a vast shallow freshwater lake, having been cut off from the Wadden Sea (001) by the Afsluitdijk (in 1932) and with 45% of its extent having been reclaimed. The original IJsselmeer was then bisected by a dyke in 1975, which separated it from the southern part now called Markermeer (038). This site adjoins three subsites 035, 036 and 037 (the figure for the area of this site excludes these subsites) which are located along the Frisian coast. The lake receives Rhine water through the IJssel river (046 and 047) via Lake Ketelmeer (039). The wetland habitat in the subsites is not included in the percentage cover for this site (to avoid overlap). Extraction of sand and water occurs, and natural-gas extraction is planned. Military training (artillery) occurs at Breezanddijk (Afsluitdijk). The lake has been locally deepened to over 25 m by sand extraction. This site, together with site 038, formed part of a single, larger site (former site NL030) in the previous pan-European IBA inventory (Grimmett and Jones 1989).
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: Numbers are based on aerial counts, which tend to underestimate those species with a scattered occurrence. This is the main moulting area for subadult Cygnus olor in the Netherlands, and the main feeding area for Phalacrocorax carbo from Oostvaardersplassen (066), although the actual numbers are poorly represented by the aerial counts. The number of Chlidonias niger is based on numbers flying to roost at Balgzand (013). Other species which do not fulfil IBA criteria include non-breeding Larus minutus (5,100 in January 1983).
Delineation rationale: 24 May 2017 - the three smaller IBAs of Makkumer-and Kooiwaard (SitRecID 1212), Workumerwaard (SitRecID 1213) and Steile Bank & Mokkebank (SitRecID 1214) have been merged into the much larger IBA IJsselmeer (SitRecID 1215), to match the SPA of the same name that was designated on 16 February 2010.
Habitats
Land use: fisheries/aquaculture (100%) | military (12%) | tourism/recreation (100%) | urban/industrial/transport (15%) | water management (100%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Coastal/Supratidal | 95 |
Threats
Summary of threats to biodiversity at KBA: The main problems are over-fishing, water management (level deliberately kept high during summer to supply water for farming), pollution by nutrients from the River Rhine/IJssel and by trace pollutants such as cadmium, mercury and DDT (`Other' threat, above), entanglement in fishing nets (involving thousands of birds), and recreation (leisure boating).
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Marine & freshwater aquaculture | Industrial aquaculture | Ongoing |
| Residential & commercial development | Tourism & recreation areas | Only in the future | |
| Human intrusions & disturbance | Recreational activities | Ongoing |