The amount of data collected during research and monitoring programs is increasing continuously. In the meanwhile know-how is constantly evolving. As data are very valuable it is important to ensure that they are managed efficiently during and after each project. More and more, funding agencies impose a data management plan (DMP) included in the proposal based on specific guidelines which are also used during the evaluation process. Such a DMP defines all aspects of data management, metadata generation, data preservation and analyses before the project begins. 4DEMON has the aim to centralize, integrate and valorize data on contamination, eutrophication and ocean acidification produced during expeditions in the Belgian Coastal Shelf (BCS) since 1970. It is a data-oriented project with two National Oceanographic Data Centres (NODC) as partners, BMDC and VLIZ. The data requirements of the funding agency (BELSPO) were implemented during the proposal by working out an efficient data workflow. As shown below, the intermediate results of the studies based on the resuscitated and valorized data are very promising.