How Boats Spread Invasive Species


Much of the ongoing spread of aquatic invasive species (AIS) to inland waters throughout North America can be attributed to the overland movement of powerboats, small commercial and recreational fishing boats, sailboats, personal watercraft, canoes and kayaks, pontoon boats, and other boats that can be towed owerland on trailers. Translocation of organisms by boaters can be intentional (e.g., as bait), but is often unintentional, with invasive species inadvertently carried in bilge water, live wells, and bait buckets. Invasive species can also be entrained on boat exteriors, e.g., entangled on propellers and trailers, attached to other entangled organisms. Thus, every time a boat is transported overland after use in an invaded waterway, there is the possibility that it will transfer AIS to uninvaded waterways.


Overland transport of small-craft boats is thought to be responsible for the spread of spiny waterflea (Bythotrephes longimanus), Eurasian watermilfoil (Myriophyllum spicatum), and zebra and quagga mussels (Dreissena spp.). These organisms are known to have considerable negative effects on the aquatic ecosystems they invade, with impacts including damages to fisheries, interference with raw water usage, decreased property values, extirpation of native species, and threats to human health.


Check out our photo gallery to better understand all of the places invasive species can hitch a ride on your boat or trailer.


clean, drain, dryboat washer

*Note: The text above was excerpted from, "Aquatic Invasive Species Transport via Trailered Boats - What is Being Moved, Who is Moving It, and What Can be Done," J.D. Rothlisberger, W. L. Chadderton, J. McNulty, and D.M. Lodge, American Fisheries Society, 35(3):121-132.