The pathways used by invasive species to move to new locations are not always obvious. Many problematic species, diseases and parasites have been transferred to new locations as undetected and unintentional hitchhikers. Rapid response is essential when a new organism is discovered in an area and it displays a high potential for developing into a nuisance species.
Rapid assessment and response involves assessing the size of the infestation relative to the resources and tools that are available to completely remove the infestation (“eradication”). Eradication is always the primary goal of rapid response. Anything less than eradication means that the pest and the problems it may cause are here to stay. In many cases, however, eradication may not be feasible. This is particularly true in aquatic systems where detection and control are difficult and a species may spread rapidly. Rapid response in these instances involves assessing which goals are attainable and most cost effective. The final response may have one of several possible goals, such as containing the problem entirely to a given area, or suppressing the population to slow its spread, or, containing the new invader and preventing its spread to new locations. Three significant requirements for a successful eradication effort are: 1) access to the target organism, 2) persistence of effort, and 3) adequate tools to control the populations.
A basic rapid response includes:
rapid confirmation of the identity of the suspicious organism;
assess the extent of the infestation;
quarantine of the infested area, if possible;
quick review of available control options to choose one best suited for the treatment conditions;
application of the chosen control option(s); and,
modification of the control strategy as indicated by the results (“adaptive management”).
There are many rapid response plans available to modify as needed for species-specific plans or for general approaches that can be customized as appropriate. Please visit the ANS Task Force web site for additional information.
A new tool that will allow us to more rapidly detect and thus respond to new infestations is eDNA. The Fish and Wildlife Service (Service), through the Great Lakes Restoration Initiative (GLRI), is partnering with the University of Notre Dame to develop a surveillance program for invasive species at risk of invading the Great Lakes. This technology uses suspended DNA in the aquatic environment (environmental DNA or eDNA) to confirm the presence of organisms present in low numbers and possibly “invisible” to traditional sampling methods. This new and innovative technology should be expected to significantly benefit many Service programs working with aquatic species by allowing us to detect invasions earlier thus giving us a greater chance to eradicate or effectively contain the infestations.