Water purifying effect soil organisms Wadden Sea

The map shows contribution to the water purifying effect by filtration by mussels in the Wadden Sea expressed in litres per square metre of soil area per day. Soil organisms such as shellfish depend on water for their food supply but at the same time also have a purifying effect on the water by extracting floating material from the water. As a result, they influence the water quality in terms of suspended dust content and transparency. The water purifying effect by shellfish is not uniformly distributed but is partly dependent on the spread of the shellfish. In addition, the purifying effect of shellfish in tidal systems such as the Wadden Sea is also influenced by the action of the tide that determines the duration of the flood. The map gives an indication of the purifying effect of shellfish, with as an indicator the amount of water filtered by mussels per unit of time per surface.