Since 2006, the ‘VLIZ Alien Species Consortium’ has collected data and information on species that were introduced by humans in marine and brackish habitats and have established reproducing populations in the study area. The consortium consists of a network of experts in marine and brackish environments in Belgium, representing more than 22 different institutions and supported by a secretariat hosted at Flanders Marine Institute VLIZ. Evidence on invasiveness is reported for 12 of the 73 alien species that are currently included in the checklist for the study area (October 2014). The network brings together scientific information from distributed sources in a central platform. It is a first step to developing an evidence-based approach to inform environmental policy objectives for Belgian marine waters and support effective measures to address invasive alien species in the study area. The information platform and species checklist are presented, approaches for collection and integration of information are described, and opportunities for collaboration between information systems at different governance levels are briefly discussed.