The IMERS database was set up at the Flanders Marine Institute (VLIZ) in response to the growing need of a general repository that could store the data resulting from sampling campaigns in a uniform way. The database has been designed for storing measurement data based on sampling of water, sediment, suspended matter and biota. The measurement data, the so-called readings, are stored together with a maximum of information on the actual sampling event that lay at the basis of the measurement.