Estimating overland transport frequencies of invasive zebra mussels

Project manager: Mike McCartney

Funded by: Brunswick Freshwater Boat Group, Brunswick Public Foundation, Tonka Bay Marina

Description: Zebra mussel invasions of inland lakes in Minnesota are on the rise. In order to develop prevention and control methods, it’s crucial to understand the pathways and mechanisms that are enabling this spread. One suspected source of human-assisted zebra mussel transport is through residual water in recreational boats. The lack of data around this concern (to support it or to rule it out) has led to challenges related to statewide inspection practices and even recreational boat design.

Therefore, the goals of this study are to:

  1. Estimate the relative contributions of different surfaces and compartments on and in recreational boats and trailers to the transport of zebra mussels and their larvae (veligers), focused on measurements of the concentrations of veligers in residual water across a full range of vessel types in Minnesota.

  2. Identify “high-risk” vessel types and “high-risk” areas of watercraft that are likely to transport large volumes of residual water, and evaluate where boat redesign can be targeted to most effectively reduce residual water volumes.

  3. Develop a refined model to assess the risk for residual waters to transport – and thereby spread – live veligers within the state.

This study will partner with the DNR’s watercraft inspection program to collect data on presence and location of adult zebra mussels on seven different watercraft types leaving two popular zebra mussel infested lakes in Minnesota. In addition, a subset of the boats inspected will have residual water – that which is left in a boat after a user has attempted to fully drain it – sampled from various compartments of the watercraft, including live wells and bait wells, bilge areas, ballast tanks (if present), motors and any other location that may potentially transport a zebra mussel. The water will be analyzed for the presence of veligers. Additionally, lab tests and field experiments will determine the ability of veligers to survive in some of these high-risk compartments.

Project start date: 2015

Estimated project end date: 2018

Updates and progress: