Field evaluation of toxicity of low-dose molluscicide treatments for zebra mussel veligers

Project manager: Mike McCartney

Funded by: Hennepin County

Project description:

This project will evaluate the potential to control zebra mussel populations by targeting their larvae (veligers) and by focusing on suppression, rather than eradication. Researchers will test EarthTec QZ® (a copper sulfate formulation) on veligers in Lake Minnetonka to determine lethal concentrations and time to lethality.

This research will have real-world implications for AIS prevention and management. Potential benefits include lowering ecologic and economic impacts by reducing zebra mussel population sizes, preventing spread by reducing densities of veliger larvae in lakes, and lowering the risk of transport of larvae and mussels by recreational boaters.  This research is the first-ever attempt to study EarthTec toxicity to veliger larvae under close-to-natural conditions in field experiments within a zebra-mussel infested lake.

The first season of field trials (2016) showed promising results, including:

  • Statistically robust estimates of how much EarthTec is required to kill 99% of veligers. The dosage is considerably lower than what is required to kill adults.
  • More details on how much exposure time is required to be effective.

Field work is ongoing in the summer of 2017.

Currently, no options exist to eradicate zebra mussels. These results suggest that low-dose treatments of EarthTec in open waters will be effective at killing veliger larvae. Because zebra mussels have such short life spans, they rely on heavy veliger production to stay successful as a species. Targeting veligers is a very promising way to reduce overall population size.

Project start date: 2016

Estimated project end date: 2017

Updates and progress: