Starting the stowaway pathway: the role of dispersal behavior in the invasion success of low-mobile marine species

Research Summary by Abby Bezrutczyk

Ros, M., Navarro-Barranco, C., González-Sánchez, M. et al. Starting the stowaway pathway: the role of dispersal behavior in the invasion success of low-mobile marine species. Biol Invasions 22, 2797–2812 (2020).


Aquatic invaders can enter a new area with the help of long distance anthropogenic transport, playing stowaway in ballast water or on ship hulls. However, it’s not fully understood how aquatic invaders reach that dispersal vector in the first place, or why some species fail to spread while other closely related species from the same area succeed. Ros and colleagues addressed these questions by studying movement of peracarid crustaceans– a group of species that generally has low mobility because they lack a larval stage– near the Strait of Gibraltar. By sampling peracarid communities that established on bath puffs set out near and far from a marina for 3 or 15 days, and sampling assemblages on the bottom of pontoon boats, the researchers were able to use colonization rates as a proxy for natural dispersal tendency. They found that the species already widespread beyond the marina also had a higher tendency to locally disperse, and having a high dispersal propensity made the species more likely to become stowaways. 

Key Takeaways:

  • The ability of low-mobile marine species disperse locally can translate to its ability to disperse globally
  • Species that disperse well locally are more likely to become stowaways
  • Certain traits can help predict the species ability to disperse well locally: being tube-dwelling, omnivorous, and having high invasion potential.

Management Implications: (As written in Ros et al. 2020)

  • Consider the Pathways: The role that local natural dispersal plays at the beginning of the stowaway pathway in low-mobile marine invaders should be more fully integrated into research on managing the risk of this invasion pathway.
  • Clean Widely: Considering that even low-mobile invaders could colonize empty niches in short-time periods, transient boats (as well as ropes, buoys and other submerged structures associated with boating activity) should be cleaned before leaving each marina.
  • Clean Carefully: Cleaning must be done even if the boat’s hull is apparently clean, because there may be small invaders that have managed to colonize it.