Changing up the fight against zebra mussels in Lake Minnetonka

June 15, 2016

The Tonka Bay Marina announced they are partnering with The Minnesota Aquatic Invasive Species Research Center, the Brunswick Freshwater Boat Group and the Minnesota Department of Natural Resources to launch new research program aimed at reducing the spread of invasive zebra mussels by recreational boaters.

This is the first phase of a program to identify the primary ways people spread zebra mussels. Specifically, this project will examine the spread of aquatic invasive species from water left in a boat after its operator has attempted to fully drain it.

To minimize the risk of spreading aquatic invasive species, Minnesota law requires that drain plugs and other water-controlling devices be removed from boats and other water-related equipment when draining a boat. Further, these drain plugs must remain out and open while transporting boats and other water-related equipment.

For various reasons, some watercrafts do not fully drain and instead retain residual water in compartments and equipment, such as engines, bilges, ballasts and live wells to hold fish. This residual water can contain microscopic zebra mussel larvae called veligers, but backers of the new program said there is no comprehensive study of vessel types that are common on today’s lakes.

Researchers will measure the amount and location of residual water in the compartments of different types of boats and equipment to evaluate concentrations and survival rates of zebra mussel veligers in residual water. This data would help boat designers and manufacturers identify where possible redesigns or retrofits might be warranted to reduce the inadvertent spread of these invaders, research organizers said. It would also influence the state’s aquatic invasive species inspection procedures and decontamination requirements.

The role of residual water in zebra mussel spread was identified as a high priority in Minnesota Aquatic Invasive Species Research Center 2014-2015 systematic assessment of research needs, and that assessment struck a chord with Tonka Bay Marina Chief Executive Officer Gabriel Jabbour.

“If boats owners are spending more time to clean these invasive species out of awkward nooks and crannies of their craft, it means less time on the lake,” Jabbour said. “And if a simple boat redesign could eliminate the problem, it just seems like a no-brainer. We need the help of science now for the more complex boats. Manufacturers may be in a position where a redesign now could head off more serious problems down the road. This research will show them what they may need to do.”

Dr. Michael McCartney, lead zebra mussel researcher at the Minnesota Aquatic Invasive Species Research Center, said he sees the benefit in boat manufacturers, boat inspectors, and boaters all being better informed about the role that residual water may play in the spread of aquatic invasive species.

“To date, we’ve had limited data to understand the risk posed by veligers in residual water,” McCartney said. “This study will considerably improve the data set – and our confidence in evaluating that risk in order to minimize it.”

“The results of this study will provide us with critical information that will be used to inform and, if need be, improve our inspection protocols,” said Minnesota DNR Invasive Species Unit Supervisor Heidi Wolf.

The DNR will contribute nearly $50,000 in-kind to the project. This includes statewide watercraft inspectors to collect samples, fleet travel, and boat use. The Minnesota Aquatic Invasive Species Research Center is contributing in-kind researcher salary, labs and other facilities. Tonka Bay Marina is providing approximately $50,000 to support a graduate student and core research costs. Additionally, Tonka Bay Marina will be providing support through staff and facilities on Lake Minnetonka.

In addition to a financial contribution, the Brunswick Freshwater Boat Group will engage its Product Development and Engineering staff to review watercraft designs that would slow or eliminate the spread of aquatic invasive species.

“Such a collaborative effort among academia, business and regulators was quite appealing in tackling such a vexing concern as aquatic invasive species,” said Brunswick Freshwater Boat Group Vice-President of Product Development and Engineering J.D. Sienicki. “We are looking forward to what may arise from this work, and how it will ultimately make boating more convenient and worry-free for boaters.”