Monitoring & Prevention

Managers and Researchers

Scientific researchers and resource managers undertake a variety of activities targeting invasive mussels in the field. While work in the field is integral to containing the spread of mussels and informing future management decisions and activities, prevention is equally as necessary for researchers and managers as it is for any other water body user. Fieldwork and prevention activities must always be compliant with relevant state, provincial, and federal protocols and regulations. Always adhere to any agency recommendations for fieldwork and prevention, as some prevention methods may not be allowed and/or suitable in all areas.

Preventing the Spread of Invasive Zebra and Quagga Mussels:
A Reference Guide for Methods of Decontaminating Gear and Equipment

Sampling activities and fieldwork often take users into areas where conventional methods of decontamination may not be readily available. In situations where it is possible and/or necessary to disinfect watercraft and gear, the Invasive Mussel Collaborative has developed a decontamination reference guide that summarizes available options for the treatment of zebra and quagga mussels. This guide is designed as one-page, front and back, for ease of transport in the field.

Not all methods presented in the reference guide are appropriate or feasible for all gear types and/or all situations.
State and local agencies may recommend, require, or permit specific methods of decontamination for specific gear types or locations.
Some decontamination methods can be scaled to meet specific needs.
States may regulate decontamination runoff as wastewater and additional action may be needed to properly dispose of runoff water.
Surrounding plants and soils could be harmed if decontamination is done improperly.
Know your local, state, and federal regulations before use of any of the methods.

Undertake decontamination efforts only after surfaces are visibly clean, drained, and dry. For more in-depth gear-specific and method-specific decontamination information, visit the Wisconsin Department of Natural Resources’ decontamination and disinfection website. The decontamination protocols presented in this guide were gathered and compiled from various United States federal and state agencies. Visit our Library for links to specific protocols.

Monitoring Protocols and Programs

Consistent monitoring practices are an integral component of prevention planning for invasive mussels. Early detection of new introductions is key to preventing establishment of new populations and presents the best opportunity for effective treatment and possible eradication.

Monitoring Techniques

The techniques used to monitor a body of water for invasive mussels may shift depending on the monitoring objective and available resources. In instances of routine monitoring, presence/absence methodology may be sufficient, while areas with a suspected introduction of invasive mussels may require more intensive techniques. Per the National Park Service, there are three primary methods of monitoring for new populations of invasive mussels:

“The inability to predict which water body will become infested makes a widespread early detection program critical.”

Upper Colorado Region Prevention and Rapid Response Plan for Dreissenid Mussels

U.S. Bureau of Reclamation

1. Settling Plates/Samplers

Samplers provide artificial substrate for invasive mussel larvae, or veligers, to settle on. Samplers can be easily constructed from low-cost materials and suspended at various water depths, providing a low-effort sampling option. This method is most viable during invasive mussel spawning periods, which typically begin in early spring and may continue into late fall or early winter, depending on location.

2. Veliger sampling

Plankton tow nets can capture veligers, which must be detected in a lab. Conducting plankton tows is fairly resource-intensive, but may provide the greatest chance for early detection if a population of invasive mussels is too small to be detected otherwise. Like samplers, veliger sampling is only effective during the period of time in which invasive mussels may be spawning.

3. Diver Surveys

Diver surveys may be conducted via snorkel or SCUBA, and are useful in areas where an introduction is suspected. Diver surveys may also be resource-intensive, depending on the area being sampled and the number of personnel required. However, diver surveys can often provide immediate survey results with minimal sampling processing time.

More detailed information about monitoring protocols and sampling methods, including those not mentioned above, is available in our Library, along with other resources for developing early detection programs. If you would like more information about a jurisdiction’s monitoring program or requirements for sampling, please visit our Find an Expert page.