Over 180 and 140 aquatic invasive species (AIS) have been introduced into the Great Lakes and Upper Mississippi River basins, respectively, with threats of new invasions always on the horizon. Sea lamprey, zebra mussels, and Asian carps are just a few examples of AIS whose abilities to alter aquatic habitats and disrupt food cycles threaten many outdoor recreation opportunities and ecosystems for future generations. Resource agencies and decision makers identify AIS as one of the most serious problems they face in the United States. Currently the lack of effective control techniques and management options result in detrimental economic and ecological effects. This research is part of a larger USGS and partner effort to investigate the life cycles of AIS and develop methods and tools to control these invasions and their impacts on aquatic waters and society.
Lake Trout in the Great Lakes are desired by commercial and recreational anglers, and can be impacted by invasive species like Asian carp and zebra mussels. |
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Presently, there is no method to control dreissenid mussels (e.g., zebra or quagga) or Asian carp in aquatic systems without attempting total remediation of that system, resulting in the death of all fish and likely all mussels within that aquatic system. The vast majority of approved management chemicals are applied as a solution, exposing target and non-target animals to the same toxic dose. To reduce the collateral damage caused by these exposures, the Upper Midwest Environmental Sciences Center (UMESC) is currently developing control tools that could be applied as part of a species-specific integrated pest management program to control AIS.
Recent advances have created the potential to develop new bioactive compounds and new targeted oral delivery techniques to increase species-specific control of invasive species within priority aquatic systems such as the Great Lakes and Mississippi River. Development of a targeted oral delivery technique could deliver biocides to a specific AIS and may increase the selectivity and effectiveness of both current and new management chemicals and biological agents. Application of AIS control strategies will not target an entire basin or Great Lakes, but would be focused on specific AIS habitat to reduce its abundance or reproductive capacity while allowing survival of native species. This research could substantially improve the ability of natural resource managers to selectively target AIS with techniques that would substantially limit the exposure of native species. |
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 Approach
A coordinated research strategy will be implemented to identify appropriate integrated pest management strategies with which to control AIS. Four research areas, which include (1) description of AIS life history traits, (2) identification of potential delivery locations within AIS, (3) development of application/delivery methodologies, and (4)characterization and registration of potential bioactive compounds, will be integrated to develop AIS control technology to provide natural resource managers withadditional management tools.
- Life history - Research will focus on identifying susceptible “weak” points in the invader’s life history (e.g., feeding, reproductive, physiological, or immunological characteristics) or habitat preferences that could be exploited. Available AIS life history information will be synthesized and compared to native species to determine how/where/when invasive species are vulnerable to control strategies.
Products and Efforts:
- Developed a consolidated database of native and non-native aquatic animal life history characteristics.
- Initiate research to compare native unionid and dreissenid mussel filtration rate and diet selectivity (e.g. algal constituents which increase retention).
- Initiate research to develop current and potential AIS distribution and abundance in relation to native species distributions and water use.
- Identification of organism-level target delivery sites - Research will be conducted to identify and characterize potential bioactive agent delivery sites within AIS including the gill, skin, and GI tract (gastric or post-gastric). Research will focus on collection of data on the physiological characteristics of both AIS and native species (e.g., enzyme, protein, lipid, carbohydrate components, pH) to provide an understanding of factors that might affect delivery of a bioactive agent. While some basic research is available in this area, additional basic and applied research may lead to development of optimized delivery components to enhance selectivity and sensitivity.
Products and Efforts:
- Determine the biochemical characteristics of the digestive gland and gill of native unionid species and of zebra and quagga mussels.
- Initiate research to characterize gut pH and digestive enzyme profiles of Asian carps.
- Initiate research to compare the gill filament and raker ultrastructure of Asian carps with native planktivores.
 
- Application strategies - Research on optimal application strategies (e.g. methods, timing, and habitat) is needed to enable maximum control. This research effort will require integration of life history information, potential identification of pheromone cues and signaling, and delivery system optimization. Results obtained from this research focus will allow resource managers to effectively target and deliver management chemicals at the right time, in the right method, and in the right amount to achieve maximum control.
Products and Efforts:
- Develop techniques to incorporate potential molluscicides into one or more delivery platforms.
- Determine the oral toxicity of rotenone and antimycin to Asian carp.
- Initiate development of techniques to incorporate registered piscicides into a targeted delivery platform
- Initiate synthesis of GD-174 (2-[digeranylamino]-ethanol) and analogues.
- Registration research - A suite of data must be developed on current and potential bioactive compounds prior to application in the wild. Analytical methods will be developed to quantify the bioactive compound in tissue, water, the delivery vehicle, and in environmental samples (water/sediment).
 Research will focus on characterizing the risk of exposure for non-target species resulting from exposure to potential bioactive compounds. Studies will also assess the potential human health effects of these residues in non-target species that may be available for human consumption. Degradation data will also be required for these compounds to evaluate their potential fate and effects in the receiving environment.
Products and Efforts:
- Initiate plans for FY2011 chemical registration meeting of research, management and regulatory agencies/entities focused on the development of management tools to control aquatic invasive species within the Great Lakes.
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