Adapted for invasion? Comparing attachment, drag and dislodgment of native and nonindigenous hull fouling species
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Invasive species possess unique traits that allow them to navigate the invasion process in order to establish and spread in new habitats. Successful hull fouling invaders must resist both physical and physiological stressors associated with their voyage. We characterised attachment strength and drag coefficient of common fouling species in order to estimate the velocity required to dislodge them from boat hulls. We hypothesized nonindigenous fouling species would possess biomechanical properties that enable them to remain attached to hulls more successfully than similar native species. Indeed, the well-known invasive ascidian Styela clava had both high attachment strength and low drag coefficient and its dislodgment velocity was well above that of fast moving vessels. In contrast, the native congener Styela gibbsii had low attachment strength and higher drag coefficient. Colonial invasive species employed a different hitchhiking strategy; despite their low attachment strengths, Botrylloides violaceus and Didemnum vexillum had low drag coefficients allowing them to be transported on slower-moving vessels, such as sailboats and barges. The biomechanical adaptations of invasive species show promise in predicting future invaders and informing vector management strategies at the first node in the invasion process: transport by the vector.
KeywordsHull fouling Biomechanics Dislodgment velocity Attachment strength Drag coefficient
The authors wish to thank N. Backe, B. Claman, T. Goodman, M. Herborg, J. Nelson and C. Simkanin for field and laboratory assistance. We are grateful to Megan Mach for creating the illustrations in the manuscript. Detailed comments by L. Brown, K. Demes and two anonymous reviewers improved earlier versions of this manuscript. Conference travel support was provided by the Canadian Aquatic Invasive Species Network (CAISN). Research funding was provided by the Aquatic Invasive Species program of Fisheries & Oceans Canada as well as a Natural Sciences and Engineering Research Council (NSERC) Postgraduate Scholarship and a University of British Columbia (UBC) Affiliated Fellowship to CCM.
- Abbott DP, Johnson JV (1972) The ascidians Styela barnharti, S. plicata, S. clava, and S. montereyensis in Californian waters. Bull South Calif Acad Sci 71:95–105Google Scholar
- Clarke CL, Therriault TW (2007) Biological synopsis of the invasive tunicate Styela clava (Herdman 1881). Can Man Rep Fish Aquat Sci 2807:23Google Scholar
- Field D (1999) Disaster averted? Black striped mussel outbreak in northern Australia. Fish Farming Int 26:30–31Google Scholar
- Hoppe KN (2002) Teredo navalis: the cryptogenic shipworm. In: Leppakoski E, Gollasch S, Olenin S (eds) Invasive aquatic species of Europe: distribution, impacts, and management. Springer, New York, pp 116–119Google Scholar
- Koehl MAR (1984) How do benthic organisms withstand moving water? Am Zool 24:57–70Google Scholar
- Koehl MA (2000) Mechanical design and hydrodynamics of blade-like algae: Chondracanthus exasperatus. In: Spatz HC, Speck T (eds) Third international plant biomechanics conference. Thieme Verlag, Stuttgart, pp 295–308Google Scholar
- McMahon RF (1996) The physiological ecology of the zebra mussel, Dreissena polymorpha, in North America and Europe. Am Zool 36:339–363Google Scholar
- Pawlik JR (1992) Chemical ecology of the settlement of benthic marine invertebrates. Oceanogr Mar Biol Annu Rev 30:273–335Google Scholar
- Schwindt E (2007) The invasion of the acorn barnacle Balanus glandula in the south-western Atlantic 40 years later. J Mar Bio Ass UK 87:1219–1225Google Scholar
- Vogel S (1984) Drag and flexibility in sessile organisms. Am Zool 24:28–34Google Scholar
- Vogel S (2003) Comparative biomechanics: life’s physical world. Princeton University Press, PrincetonGoogle Scholar