The coastline inhabiting rove beetles (Coleoptera: Staphylinidae) of Atlantic Canada are surveyed. Thirty-three species have now been recorded in Atlantic Canada including 26 in New Brunswick, 15 in Newfoundland, 31 in Nova Scotia, and 13 on Prince Edward Island. Oligota parva Kraatz, Acrotona avia (Casey), Strigota ambigua (Erichson), and Myrmecopora vaga (LeConte) are all newly recorded in Canada, and Bledius mandibularis Erichson is newly recorded in Atlantic Canada. We retain A. avia as a species distinct from A. subpygmaea Bernhauer and designate a lectotype for A. avia. Ten new provincial records are reported, one from New Brunswick, six from Nova Scotia, and three from Prince Edward Island. Four functional groups, halobiont (obligate), halophile (facultative), haloxene (tolerant), and incidental coastal species, are distinguished and the fauna is examined from the perspective of the particular coastline habitats and microhabitats they have been found to inhabit. Fourteen of the 33 staphylinids are introduced, Palearctic species, and eight of these have been associated with historical dry ballast shipping to the region from Great Britain. A trophic analysis indicates that some species are phytophagous algae feeders, while others are either generalist predators, or predators specializing on particular taxonomic or functional groups of invertebrates. Finally, some attention is devoted to discussing the diminished areas of coastline environments such as coastal marshes, and the various kinds of environmental disturbances and degradations they have experienced. These indicate the potential vulnerability of such coastal habitats and consequently of the communities of beetles that inhabit them.
