Oosterschelde (1206)
Netherlands, Europe
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2016
National site name: Oosterschelde
Central coordinates: Latitude: 51.5833, Longitude: 3.9333
System: marine, terrestrial
Elevation (m): -44 00
Area of KBA (km2): 369.75938
Protected area coverage (%): 100.00
KBA classification: Global
Legacy site: Yes
Site details
Site description: This 40-km long water-body was formerly an estuary of the Rhine/Maas river system, via Hollands Diep (025) and Lake Volkerak (026), but has been closed off from the sea since 1986 by a storm-surge barrier which allows the tidal regime to continue with some restrictions. The sea can be completely shut out during storms or high tides. Two freshwater lakes have developed on the eastern side following the construction of secondary dams (Markiezaat and Zoommeer, 029 and 030). South of this area, Lake Veersemeer (031) came into being following the closing of the Veerse Gat in 1961. This site, together with sites 029 and 030, formed part of a single, larger site (former site NL050) 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: This is the most important intertidal staging area for ducks and waders in south-west Netherlands. Thousands of geese Anser, feeding in adjacent farmland polders, use the area as roost. Recurvirostra avosetta and Charadrius alexandrinus breed in small lagoons (`inlagen', inland of the dyke) and at Neeltje Jans (building site of storm-surge barrier).
Delineation rationale: 9 March 2017: name and area edited. Now equal to the designated Special Protection Area (Birds Directive).
Habitats
Land use: fisheries/aquaculture (80%) | nature conservation and research (65%) | tourism/recreation (80%) | urban/industrial/transport (21%) | water management (100%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Intertidal | 50 | |
| Marine Neritic | 50 |
Threats
Summary of threats to biodiversity at KBA: The main problems are: the reduction of tidal volume and flow-speed by 30% due to the building of the storm-surge barrier; cockle Cardium fisheries and shellfish farming; disturbance by ultra-light aircraft and by the air force; and the expansion of recreation (boating). The SPA and Ramsar designations also include Markiezaat (030).
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Annual & perennial non-timber crops | Shifting agriculture | Ongoing |
| Agriculture & aquaculture | Marine & freshwater aquaculture | Industrial aquaculture | Ongoing |
| Biological resource use | Hunting & collecting terrestrial animals | Unintentional effects (species being assessed is not the target) | Only in the future |
| Pollution | Excess energy | Light pollution | Ongoing |
| Human intrusions & disturbance | Recreational activities | Ongoing | |
| Climate change & severe weather | Habitat shifting & alteration | Ongoing | |
| Transportation & service corridors | Utility & service lines | Ongoing |