The British and Irish aquatic animal telemetry community study a wide diversity of aquatic animals across freshwater and marine ecosystems. To track their movements at appropriate spatial and temporal scales, this European Tracking Network (ETN) Network Project will develop a permanent, interoperable and cost-effective acoustic telemetry receiver array throughout British and Irish waters. Doing so will help ensure telemetry-derived knowledge is collectively gathered to inform evidence-based management and conservation of British and Irish freshwater and marine biodiversity and ecosystems.