A number of important estuaries are situated in the North Sea area. The estuaries have a great ecological value and provide space for important economic activities. All estuaries face common challenges such as increasing flood risks, issues with regard to sediment management and the preservation of ecosystem functions. The Sea Scheldt and its tidal tributaries (Durme, Rupel with the Zenne, Dijle and Netes), the Western Scheldt and the mouth of the Scheldt together constitute the Scheldt estuary. The water bodies and flood plains are subject to the tides of the North Sea. Hence, a strong interaction exists between the Scheldt estuary and the North Sea. In the ‘Thematic chapter’, an overview is given of the scientific knowledge, socioeconomic data and legal aspects of the Scheldt estuary. The international legislation applicable to this geographical region is discussed in more detail under ‘Legislation’. More information about the available expertise regarding the Scheldt estuary within the Belgian marine research groups can be consulted by clicking ‘Research groups’, which will redirect you to the Scheldt Monitor.