The aim of a World Register of Marine Species (WoRMS) is to provide an authoritative and comprehensive list of names of marine organisms, including information on synonymy. While highest priority goes to valid names, other names in use are included so that this register can serve as a guide to interpret taxonomic literature.The content of WoRMS is controlled by taxonomic experts, not by database managers. The WoRMS has an editorial management system where each taxonomic group is represented by an expert who has the authority over the content, and is responsible for controlling the quality of the information. Each of these taxonomic editors can invite several specialists of smaller groups within their area of responsibility to join them. It is a voluntary-based initiative, that receives (in)direct support from different institutions supporting the taxonomic editors, and of the Data Management Team (DMT) members at the Flanders Marine Institute, Belgium.

This register of marine species grew out of the European Register of Marine Species (ERMS), and its combination with several other species registers maintained at the Flanders Marine Institute (VLIZ). Rather than building separate registers for all projects, and to make sure taxonomy used in these different projects is consistent, VLIZ developed a consolidated database called Aphia. MarineSpecies.org is the web interface for this database. The WoRMS combines information from Aphia with other authoritative marine species lists which are maintained by others (e.g. AlgaeBase, FishBase). Resources to build MarineSpecies.org and Aphia were initially provided mainly by the EU Network of Excellence Marine Biodiversity and Ecosystem Functioning (MarBEF), and also by the EU funded Species 2000 Europe and ERMS projects. Today, the WoRMS is hosted and maintained by VLIZ.