The increasing occurrence of introduced invasive species in coastal marine ecosystems causes concern for the maintenance of local ecological processes, functions and services. Therefore, the global problem of introduced species is a major issues considered within the European Marine Strategy Framework (MSFD; Directive 2008/56/CE) to reach a good environmental status in the European seas. In the North Sea, one species native to the North-Eastern American coast, the American razor clam Ensis directus, has established permanent populations since it reached the German Bight in the late 1970s. This now widespread species is present at the Belgian coast since the 1980s, with large amounts of dying specimens and shells periodically washing ashore. So far, it has been little documented due to its ability to dig deep in the sediment, but questions have arisen relative to its population size, distribution and environmental impact. Its abundance also triggers questions on a possible exploitation by specialized fisheries, as is already the case e.g. in Dutch waters.