Estuaries and Coasts

, Volume 37, Issue 6, pp 1572–1581

Transient small boats as a long-distance coastal vector for dispersal of biofouling organisms


DOI: 10.1007/s12237-014-9782-9

Cite this article as:
Ashton, G., Davidson, I. & Ruiz, G. Estuaries and Coasts (2014) 37: 1572. doi:10.1007/s12237-014-9782-9


Alaska is at the northern end of an apparent latitudinal trend of decreasing coastal marine introductions on the West Coast of North America. Historical propagule supply may have played a role in forming this trend, but few studies have evaluated propagule supply to northern latitudes. Here, we examined the role of small boat traffic as a mechanism of long-distance spread for nonindigenous species (NIS) into coastal Alaska. We used a combination of public records, marina surveys, and boater interviews to characterize vessel traffic patterns and boater behaviors. In-water SCUBA sampling of recently arrived transient boats provided data on extent, richness, composition, and biogeography of biofouling incursions to Alaska from outside of the state. We documented a striking seasonality and directionality of vessel traffic, and most vessels were on voyages of >900 km. Most transient vessels sampled had few organisms, although one third had >100 organisms on submerged surfaces. Several NIS were recorded, including two that are not known to be established in Alaska (Watersipora subtorquata and Amphibalanus improvisus). The seasonal northward pulse of vessels and their cumulative biofouling species represent an important incursion mechanism for species yet to establish at the northern edge of a marine bioinvasion front in the northeastern Pacific. The low numbers of NIS sampled in this study coincide with the low number of marine NIS known from Alaska, which suggests that an opportunity remains to promote awareness and management of the vector to limit NIS influx to the region. This may be particularly relevant for future scenarios of increased vessel traffic and ocean warming, which are likely to interact to increase establishment success of invaders from the south.


Anthropogenic transport Biofouling Introduced Latitudinal gradient Nonindigenous species Vector 

Supplementary material

12237_2014_9782_MOESM1_ESM.docx (54 kb)
ESM 1(DOC 54.5 KB)

Copyright information

© Coastal and Estuarine Research Federation (outside the USA) 2014

Authors and Affiliations

  1. 1.Marine Invasions LaboratorySmithsonian Environmental Research CenterTiburonUSA
  2. 2.Aquatic Bioinvasion Research and Policy Institute, Environmental Science and ManagementPortland State University & Smithsonian Environmental Research CenterPortlandUSA
  3. 3.Marine Invasions LaboratorySmithsonian Environmental Research CenterEdgewaterUSA
  4. 4.British Antarctic SurveyHigh CrossCambridgeUK

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