Large numbers of small individuals (pediveligers and juveniles <5 mm) are routinely recorded in size–frequency distributions of mussel samples collected from deep-sea chemosynthetic environments. If recruitment of invertebrates to deep-sea hydrothermal vent sites were via long-distance dispersal, as is typically assumed, one would expect recruitment ‘events’ recorded in size–frequency distributions to be difficult to detect, due to loss of larvae in an open system over large distances. If one imposes mesoscale oceanographic phenomena that minimize dilution of larvae (such as eddies shed from hydrothermal vent plumes) and episodic spawning, expression of this mesoscale corralling at the level of population structure would likely be limited to discrete records of recruitment events encountered serendipitously during haphazard sampling in space and time. The ubiquity of large numbers of post-larvae in mussel samples from a number of disparate sites is likely not serendipitous, but instead may reflect the importance of local sources and sinks of propagules in maintenance of mussel populations.