Is long-distance dispersal of talitrids (Amphipoda) in the North Atlantic feasible?

Abstract

Three talitrid species were found on both northwestern and northeastern Atlantic coastal regions: Orchestia gammarellus, Platorchestia platensis and P. monodi. We used the predictive surface drifter model Adrift.org.au to determine the feasibility of long-distance dispersal in either direction across the North Atlantic. Driftwood was the only rafting platform which could support talitrids, such as Platorchestia but not Orchestia, for long enough to survive a North Atlantic crossing. It is feasible that both Platorchestia platensis and P. monodi, physiologically adapted to a driftwood dispersal platform, could undertake rafting from west to east, but not from east to west. We cannot exclude the possibility of synanthropic dispersal for Platorchestia sp., which remains a viable alternative hypothesis.