Food in abundance
Due to the constant supply of salt water from the oceans and fresh water from the rivers, lots of building materials end up in the Wadden Sea. Tiny little plants on the bottom of the Wadden Sea or floating in the shallows use these materials, making them available for other Wadden Sea inhabitants. The seawater flowing into the Wadden Sea during flood is also full of microscopically small plants (the phytoplankton) and animals (the zooplankton). This plankton forms appetizing food for larger animals, such as fish and shellfish.
Twice a day, fresh food arrives in the Wadden Sea with the tide. However, the wealth of the Wadden Sea is mainly the result of production within its own boundaries. The water in many areas is so shallow that the sun shines down to the bottom. This allows microscopically small plants to grow on the Wadden Sea floor. Worms, shellfish and Corophium graze upon these seabed plants. Filtering animals that live on or in the bottom, such as mussels, cockles and tube worms, sift the suspended phytoplankton out of the sea water. In turn, these bottom animals are eaten by flatfish and wading birds. In this way, all the plants and animals form a part of the fascinating food web of eating and being eaten.
Because the Wadden Sea is so shallow and the tide, currents and wind move freely, the available food is mixed together and spread over the entire region. Thanks to its own high food production and the constant supply of building materials and food from elsewhere, the wealth in the Wadden Sea is 20 times higher than in the adjacent North Sea coastal zone.