The World Register of Marine Species (WoRMS) started in 2007 with the question “how many species live in our oceans?”. Now, a little over 15 years later, WoRMS is able to answer several questions related to marine species discovery rates and provides a dynamic number of existing marine species, based on the information provided by hundreds of taxonomic experts worldwide, who have proven to be diverse and dynamic. We present basic statistics on marine species discovery rates based on the currently available content of WoRMS, as well as insights in the day-to-day activities and dynamics of our editorial board and the progress made so far on the content priorities as defined by the WoRMS Steering Committee. As for all dynamic systems, WoRMS is not complete and faces challenges. As an endorsed project of the UN Ocean Decade, WoRMS aims to tackle a number of these challenges and knowledge-gaps by 2030, including detailed documentation of authorships and original descriptions, and will provide continuous support to all marine initiatives, programs and projects that rely on WoRMS as an authoritative classification and catalogue of marine names.