In implementing the Birds Directive, three areas were selected in the Belgian part of the North Sea as Birds Directive Area or Special Protection zone: SPZ1, SPZ2 and SPZ3.
The Birds Directive areas were selected on the basis of the report of the Administrative Unit of the Mathematical Model of the North Sea and the Scheldt estuary (MUMM) concerning the ornithological importance of the Belgian marine waters.
Special protection zone 1 (SPZ1)
This Birds Directive Area of 110.01 km2 includes the marine area in front of Koksijde. It approximately stretches from Nieuwpoort to the French border and extends to 6 nautical miles from the coast. It consists of very shallow sandbanks and depressions between these sand banks. During low tides, the upper part or crown of the sand banks are situated barely a few meters below the water surface and sometimes some places fall dry. The top of the bank, the gullies and the water body have their own fauna which is important as a food source for various sea birds.
Due to the proximity of the Channel, the water quality in this area is determined by the water that moves through the channel rather than by the waters of the Scheldt, Maas and Rhine Estuary that is enriched with nutrients and pollutants.
The area is largely inaccessible to shipping due to its shallowness and is especially attractive in winter to quietness-loving species (great crested grebe, red-throated diver and common scoter). Grebes in particular have a strong preference to the area and sometimes flock together in large numbers (up to > 1% of the European population and up to 15% of the total population of our North Sea). In recent years (since 2000), more common scoters have been observed, but their numbers still remain mostly limited (average 449 specimens, but sometimes several thousands).
The area is also important for sea birds to rest and to forage. It is designated as a special protection zone because of its importance to the great crested grebe and the sandwich tern. Significant numbers of red-throated divers, common scoters, little gulls, lesser black-backed gulls and greater black-backed gulls also occur in the area. This area is important not only to the common tern and the little tern.
This and the following Birds Directive Area (SBZ2) overlap in part with the RAMSAR area "Western Coastal banks" that goes to a depth of 6m and that is designated for the scoters and the grebes (Melanitta nigra, Melanitta fusca, Somateria molissima and Podiceps cristatus) living there.
Special protection zone 2 (SPZ2)
This Birds Directive Area of 144.80 km2 covers the marine area in front of Oostend that stretches itself up to about the Oostend Bank. This area has a subsoil of the sand banks and depressions similar to SPZ1 and also a fauna that is an important food source for different sea birds.
This area is also important to the sea birds to forage and to rest. It is designated as a special protection zone because of its importance to the little tern (about 15% of the total population of our North Sea), the great crested grebe, the little gull, the common tern and the sandwich tern. Significant numbers of red-throated divers, common scoters, lesser black-backed gulls and greater black-backed gulls do also occur in the area.
Large parts of the area are heavily used. Terns and gull species are mainly observed there and benefit from the steep slope of the gullies, forage along the flow-separation lines for food which is easy to obtain thanks to the shipping traffic. The parts where the passage of ships is hampered by the shallow sand banks are then used by the quietness-loving species (great crested grebe, red-throated diver and common scoter).
Special protection zone 3 (SPZ3)
The SPZ3 area of 50.95 km2 includes the marine area in front of Zeebrugge. The area is of great economic importance as the access to the port of Zeebrugge. A number of benthic species - species that live in or on the seabed - and especially some species of fish (sand eel, herring, sprat etc.,),disturbed by the propellers of the ships in the port area are on the menu of sea bird species such as the sandwich tern, the common tern and little tern. They breed in the adjacent Flemish Birds Directive Area “Kustbroedvogels Zeebrugge-Heist”. It is designated as a special protection zone because of its importance to the common tern and the little gull (about 15% of the total population of our North Sea).
The area is heavily used and is therefore rarely used by quietness-loving species. Within the area, the transition between the Wenduinebank and the deeper water to the north is important to the terns as a foraging area.
In addition to the Birds Directive Areas, the entire Belgian part of the North Sea is of essential importance to the survival of some species such as the grebes, the red-throated diver, common scoter, the little gull, the lesser black-backed gull, greater black-backed gull, the sandwich tern, the common tern and little tern.