Habitats and ecosystems

Thanks to its many sandbanks, strong tides, water composition and location along migration routes, the Belgian part of the North Sea (BNS) has a special biodiversity (DG Environment 2010). As a result, it offers a variety of habitats for different animal and plant species. This dynamic set of species, living environments and the interactions between them can roughly be divided into two different ecosystems.

On the one hand, there is the North Sea ecosystem, which can be divided into a benthic and a pelagic ecosystem. The benthic zone (seabed and upper water layer) includes starfish, mollusks and crabs (macro-benthos), but also microbial communities (micro-benthos). The pelagic zone (upper water column) consists of organisms such as plankton, several fish species, etc. that occur in the upper water column.

In addition to the marine ecosystem, the coastal area on the landside can also be regarded as an ecosystem. The presence of beaches, dunes, polders, mud flats and salt marshes, grasslands and forests also make this ecosystem very biodiverse. In this way, about half of the species in Flanders can also be found on the coast. This can be explained by the typical geomorphological dynamics of the contact zone between land and sea, the characteristic microclimate and the environmental gradients dry-wet and lime-scale (Bonte & Provoost 2004).

Man makes use of many ecosystem services (Millenium Ecosystem Assessment – MEA 2005). Coastal ecosystems provide regulatory, privileged, cultural and support services. Despite the uniqueness and importance of marine ecosystem services, they are under pressure in various ways. The Belgian coastal waters are threatened by, among other things, discharges from ships, dumping of dredged material, fishing, invasive exotic species, etc. The influence of these factors is evaluated in the Report Directive 2000/60/EC - Article 5 for the Belgian coastal waters.