MACROCHESS – A Macroecological Database for Species Distribution across Chemosynthesis-Based Ecosystems is a new database incorporating over a decade of new discoveries and the most recent taxonomic knowledge of species occurring in chemosynthesis-based-ecosystems (CBEs). The database is being compiled by a working group funded by the International Cooperation in Ridge Crest Studies – InterRidge. The group is chaired by Lissette Victorero (Norwegian Institute of Water Research and CESAM-UA) and comprises 17 experts from ten countries and four continents working on hydrothermal vents, seeps and organic falls across a wide variety of disciplines. This database will enable characterising the global distribution, composition and relationship of species occurring in CBEs at both global and regional scales and hence aims to rapidly advance theoretical research and conservation efforts.