A former estuary, 18 km in length, which was closed from the sea in 1971. It is now a stagnant saline lake, mostly bordered by dykes with islets, sand-dunes and wet meadows. It adjoins the Voordelta (020) to the west, and Lake Volkerak (026) and Oosterschelde (028) to the east. Hunting does not include waterbirds.
This clear, saline lake is especially attractive to piscivorous waterbirds, and the grassland bordering the northern shores (Slikken van Flakkee) is one of the main feeding sites of Branta leucopsis in south-west Netherlands. The site holds important roosts of geese. The mean total number of waterbirds in January exceeds 20,000.
Pressure/threats to key biodiversity
Numbers of herbivorous bird species such as Cygnus olor and Aythya ferina have been much reduced due to the near-disappearance of eel-grass Zostera.
National None International None
BirdLife International (2022) Important Bird Areas factsheet: Grevelingen. Downloaded from
http://www.birdlife.org on 21/01/2022.