Data from: Transoceanic dispersal of terrestrial species by debris rafting

Rare, long-distance dispersal events are a key process in generating and
maintaining patterns in biological diversity and species distributions
across space and time. The 9.0 magnitude earthquake that struck the
eastern coast of Japan in 2011, and the subsequent 38 m high tsunami
washed large amounts of shoreline debris into the Pacific Ocean that led
to a large-scale biological rafting event carrying nearly 300 marine
species to the western shores of North America. Whether oceanic,
trans-Pacific dispersal via rafting generates long distance dispersal
events for small, flightless, terrestrial species is unknown. By sampling
beach debris associated with known hot-spots of tsunami debris along the
north and east shores of Graham Island, Haida Gwaii, Canada, I document
significantly dissimilar invertebrate communities associated with
tide-line beach debris and the occurrence of several putative Japanese
species of soil-dwelling mites (Acari: Oribatida). Previous explanations
of Haida Gwaii’s unique flora and fauna have been attributed to a
proximity to the Beringian land bridge and the accumulated evidence of
near-offshore glacial refugia during the last glacial period. However, my
research also suggests that stochastic, trans-Pacific rafting events
contribute to the biodiversity and biogeography of soil communities on the
west coast of North America.