1. A taxonomic and biogeographic information system of marine species in the Southern North Sea developed by Flanders Marine Institute Ward Appeltans, Edward Vanden Berghe & Jan Mees Flanders Marine Data and Information Centre (VMDC) Flanders Marine Institute (VLIZ) Vismijn, pakhuizen 45-52, 8400 Ostend, Belgium Introduction Aphia is a register of marine species that the Marine Data and Information Centre of the Flanders Marine Institute (VLIZ) has built and maintains since its establishment nearly five years ago. This species register (Aphia) serves as a taxonomic backbone in the management of biological data obtained by our own efforts and those coming from various national and international projects and databases. Conclusions By screening literature, from recent works to those dating back to the mid nineteenth century, we intend to get a more complete overview of our current and historical biodiversity. In addition, documenting nomenclature changes, recording synonymy and storing every species record will help in correctly interpreting old and grey literature. The structure of the database corresponds to the international formats of both the European Register of Marine Species (ERMS) and the International Taxonomic Information System (ITIS). It will be possible to give taxonomic input to ITIS and ERMS. Our biogeographic system is now already linked with and provides data to the European node of the global Ocean Biogeographic Information System (EurOBIS). Maintaining our species register and storing biogeographic information is a work in progress, which falls within VLIZ’s core activities of documenting and integrating marine biodiversity data. Figure. Database diagram – presenting tables for taxonomy, sources, biogeography (a), parent links (b) and vernaculars (c) a b c Data Currently, Aphia holds 20,000 taxa representing 65 Phyla. Apha includes 10,000 species names of which 2,200 are relegated to synonymy. Remaining names are those of higher hierarchical levels from the systematic classification. Besides pure taxonomy, Aphia contains about 3,000 vernacular names (mainly Dutch, English, French and German) and 4,000 notes regarding species biology, ecology, distribution, habitat, taxonomy and systematics among others. All the information is referred to its source, which can be a publication, an expert or a database. More recently, VLIZ started storing distribution records for the Southern North Sea. We now have nearly 40,000 distribution records for 400 localities.Technicalities Aphia is an MSSQL database with an MS Access input interface. The diagram (fig. 1) represents the different tables and links. Acknowledgement Data resulting from this work are contributing to the aims within MarBEF. MarBEF is a EU-funded network of excellence on Marine Biodiversity and Ecosystem Functioning (http://www.marbef.org). MarBEF funds allow W. Appeltans to attend the conference. # species names (valid/invalid) Animalia Arthropoda1936/257 Mollusca822/540 Chordata552/261 Echinodermata426/294 Cnidaria361/149 Others2545/533 Proctista1433/211 Fungi111/1 Plantae8/0 Monera80/25 Total8274/2271 Figure 2. Piechart – representing the percentages of species names of some of the major groups in Aphia Figure 3. Screen shot of Aphia’s webinterface. Taxonomic, bibliographic, biological and biographic information from species occuring in theSouthern North sea is availabe online at http://www.vliz.be/vmdcdata/aphia/index.htm