The European ARMS programme (ARMS-MBON) is a network of Autonomous Reef Monitoring Structures (ARMS) placed in the vicinity of marine stations, ports, marinas, and Long-Term Ecological Research (LTER) sites distributed over Europe and polar regions. The aim of ARMS-MBON is to assess the status of, and changes in, hard-bottom communities of near-coast environments, using genetic methods supplemented with image analysis and visual inspection methods. ARMS-MBON is part of GEO BONs Marine Biodiversity Observation Network (MBON). One of our scientific goals is to identify newly arrived Non-Indigenous Species (NIS) in Swedish waters, facilitating an early warning system, and to track the migration of already known NIS in Swedish waters. The project is primarily funded through the Digital Twin of the Ocean programme of the European Commission, with financial contributions from the Swedish Agency for Marine and Water Management, the DDLS program and in-kind contributions by University of Gothenburg. The project is an activity of the Genomic observatories network with relations to the European Marine Biological Resource Center (EMBRC).