Development of Selective Control Tools for Dreissenid Mussels
As invasive zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively), known as dreissenid mussels, continue their expansion throughout North America, the need to develop selective control tools has become critical for resource managers. Registered molluscicides for dreissenid control are limited, and often must be applied within or under a barrier to achieve effective concentrations. While these applications can achieve high mussel mortality, they can be costly, limited in spatial coverage, and potentially harm nontarget species.
Management Tools for Dreissenid Mussels
Dreissenid mussels (Zebra and Quagga Mussels) live in the benthic, or bottom, zone of lakes and streams attached to available substrate and each other. Current control treatments for dreissenids do not readily target the bottom unless applied under a barrier. USGS is collaborating with private-sector partners to develop formulations of existing toxicants that sink and slowly release the lethal concentrations of the active ingredient at the bottom. These improvements will increase targeted delivery of treatments to dreissenid mussels while potentially miminimizing exposure to more mobile nontarget species. Additionally, pellet formulation may be broadcast from the surface to treat larger areas. Current research on bottom release formulations is focused on the biopesticide Zequanox (manufactured by Invasive Species Corporation) and niclosamide. We are evaluating the release rate of the active ingredient from each new formulation, their lethality to dreissenid mussels , and their toxicity to nontarget species. Current testing is being conducted in the laboratory and in outdoor mescosms, with eventual pilot testing in open water systems planned in the near future.
As invasive zebra and quagga mussels (Dreissena polymorpha and D. rostriformis bugensis, respectively), known as dreissenid mussels, continue their expansion throughout North America, the need to develop selective control tools has become critical for resource managers. Registered molluscicides for dreissenid control are limited, and often must be applied within or under a barrier to achieve effective concentrations. While these applications can achieve high mussel mortality, they can be costly, limited in spatial coverage, and potentially harm nontarget species.
Management Tools for Dreissenid Mussels
Dreissenid mussels (Zebra and Quagga Mussels) live in the benthic, or bottom, zone of lakes and streams attached to available substrate and each other. Current control treatments for dreissenids do not readily target the bottom unless applied under a barrier. USGS is collaborating with private-sector partners to develop formulations of existing toxicants that sink and slowly release the lethal concentrations of the active ingredient at the bottom. These improvements will increase targeted delivery of treatments to dreissenid mussels while potentially miminimizing exposure to more mobile nontarget species. Additionally, pellet formulation may be broadcast from the surface to treat larger areas. Current research on bottom release formulations is focused on the biopesticide Zequanox (manufactured by Invasive Species Corporation) and niclosamide. We are evaluating the release rate of the active ingredient from each new formulation, their lethality to dreissenid mussels , and their toxicity to nontarget species. Current testing is being conducted in the laboratory and in outdoor mescosms, with eventual pilot testing in open water systems planned in the near future.