With TISBE, VLIZ tries to develop a comprehensive list of species recorded from the Belgian coast, the Southern Bight of the North Sea and the surrounding countries. The focal area for this database spans from northern France (rocky shores north of Wimereux, where the fauna changes dramatically) to southern Holland, including the Delta area and whole of the tidal part of the Scheldt estuary. Distributions from further away are recorded only if the are listed in publications dealing mainly with distribution records from the focus area. The precision with which the distribution records, both on the geographical and on the temporal scale, are recorded, is variable: the closer a record is to the focal area, the more details we try and record. The sources of information are mainly published literature. All distribution records contain a description of the source. Leaving such an 'audit trail' makes it possible to check the validity of every single distribution record by going back to the sources of our information. TISBE is build on top of VLIZ's species register, Aphia, and this web application always contains links to taxonomic details, and other taxon-specific information, as they are known in Aphia. From within TISBE, only those species are visible that are known to occur in the area.