Aquatic Invasive Species (AIS)

Zebra Mussel Update

by Mike McLaughlin, LICA Board Member

Zebra mussels (Dreissena polymorpha) are an invasive, fingernail-sized mollusk that is native to fresh waters in Eurasia.They are native to the Caspian and Black Seas south of Russia and Ukraine. They are easy to identify, with a distinct, flat-bottomed ‘D’ shape to their shells that allows them to sit flat against a solid surface, and black, zigzag stripes against a cream background that earned them their name. They grow around two inches long at most, and are microscopic in their larval stage, which is known as a “veliger.” They are short-lived (between two and five years), and begin reproducing at two years of age. Each female can release up to a million eggs per year. Their name comes from the dark, zig-zagged stripes on each shell. The theory is that zebra mussels probably arrived in the Great Lakes in the 1980s via ballast water that was discharged by large eastern European ships. They have spread rapidly throughout the Great Lakes region and into the large rivers of the eastern Mississippi drainage. They have also been found in Texas, Colorado, Utah, Nevada, and California. Zebra mussels negatively impact ecosystems in many ways. They filter out algae that native species need for food and they attach to--and incapacitate--native mussels. Power plants must also spend millions of dollars removing zebra mussels from clogged water intakes.

Klancke dock zebra monitor Sept 2021 - 2.jpg

“Biofouling,” or the accumulation of adult zebra mussels on almost any surfaces put in the water, is one of the more notable impacts zebra mussels can have on a local economy. Zebra mussels are armed with rootlike threads of protein, called “byssal threads,” that allow them to firmly attach themselves to hard surfaces such as rocks, native mussels, docks or boats. Typically, this isn’t a problem for boats that are only in the water for short trips, but boats, docks or intake pipes that are left in the water for a long period of time can become encrusted and be very difficult to clean. If a boat owner also fails to drain the water from his or her motor, any veligers floating in the water will root themselves and clog the machinery as they reach adulthood.

Biofouling is a problem in the ecological world as well. Zebra mussels will attach to native mussels much like they do docks, and in large enough numbers can prevent the natives from moving, feeding, reproducing, or regulating water properly causing their local extinction. The zebra mussels also outcompete the natives for food and space, and because of their fast reproduction can quickly overwhelm a water system. Viewed up-close underwater, two tiny siphons can be seen projecting into a narrow gap between the shell valves of each animal — these siphons are used to pump water for respiration and feeding.

Klancke dock zebra monitor Sept 2021 - 1.jpg

The Klancke's on South Lakeshore Drive found zero mussels 2017-2019, 30  in 2020 and thousands this year as seen on these photos of a zebra mussel collecting plate they have had hanging on their dock since 2017.

The feeding habits of zebra mussels can also have a drastic impact on an infested lake because of the way they siphon particles of plankton from the water. They are highly efficient at this, and a large population of mussels can quickly clear the water of almost all floating particles. They cause damage by consuming organisms like zooplankton, which can make it harder for species at higher levels of the food chain to find sufficient food. This change can cause shifts in local food webs, both by robbing food from native species that feed on plankton and also by increasing water clarity and thus making it easier for visual predators to hunt.The mussels can also promote algae blooms through this filter feeding process in which the mussels consume just some forms of algae that are beneficial to the ecosystem while refraining from eating detrimental varieties like blue-green algae.

In an effort to reduce zebra mussel populations, a paper released by the University of Minnesota in partnership with the U.S. Geological Survey demonstrated the most effective ways to eradicate the inch-long nasties, even in the icy waters of our state. Most chemicals used to exterminate zebra mussels are developed and tested in the warmer states located south of Minnesota, said James Luoma, a USGS researcher who was one of the leaders of the study. While these chemicals may work efficiently in warmer climates, they do not operate as well in the frigid waters of Minnesota lakes in the fall, he said. “A lot of these infestations are found late in the year when people are removing equipment such as docks or boats,” Luoma said. “In the past, [those treating zebra mussels] did not have the information available to [determine if] a product would be effective in cold waters.”


MAISRC, the Minnesota Aquatic Invasive Species Research Center, has completed sequencing of the genome of the zebra mussel in order to isolate markers to study spread and explore possible genetic weaknesses that can be targeted for control. And now, researchers have discovered how to most efficiently kill the mussels in Minnesota lakes without overusing the chemicals. The results of the study indicate that three zebra mussel treatments have the ability to exterminate more than 90 percent of the invasive populations in water temperatures of 45 degrees Fahrenheit. EarthTecQZ, Niclosamide, and Zequanox. Niclosamide, required only 24 hours of exposure to achieve a high mortality rate while the others required longer. By using the proper amounts of these products, the researchers hope to find the “sweet spot” that kills a substantial number of zebra mussels without affecting harmless non-invasive species, said Nicholas Phelps, the director of the University’s Minnesota Aquatic Invasive Species Research Center, which funded the study. In addition to testing the concentrations on zebra mussel veligers, the researchers tested those same concentrations on snails, four native fish species, one native mussel species, and Daphnia (water flea - a zooplankton species) to see how other species would respond to this type of treatment.

“This is the first time that we’ve really created a plan that people in Minnesota can actually put into action on their lakes to control zebra mussels,” said Christine Lee, communications specialist for MAISRC. By reducing the populations of zebra mussels, the researchers hope to mitigate the species‘ negative economic impact, which can total more than one billion dollars per year nationwide, according to the U.S. Department of State.

Link to an article about how to protect your boat:


Link to DNR’s page on zebra mussels:

Minnesota AIS Research Center
Fall 2021 Showcase

The University of Minnesota's AIS Research Center held their Fall 2021 AIS Showcase this past month. The event was a full day of very informative presentations held entirely online this year. Several LICA board members attended a variety of sessions and we are investigating some new ideas that could benefit Lake Independence. We will be showcasing those different ideas and sharing videos from the event here on our website over the next few months. 

Zebra Mussels - Fall 2021

This summer we have seen the largest infestation in one place when board member Mac Smith overturned his paddle boat in the end of August and found a large number of zebra mussels.


If you find zebra mussels please snap a picture and send details to us at


July 23 AIS Monitoring Update

Lake Independence has know infestations of Eurasian watermilfoil, Curly-leaf Pondweed, and Zebra Mussels, all were found during our survey. Newest to our AIS list is Yellow Iris which we found last year for the first time. This year a large patch was noted by Kristen Blanck when she was kayaking near the Lindgren lane channel. Good news is we did not find any Starry Stonewart which has made appearances in other area lakes.

A big thanks to our hosts, Pat and Dick Wulff, for serving a delicious brats and sauerkraut lunch before we headed out on the water!


Craig Olson and Kristen Blanck pull in the first rake of aquatic plants to be surveyed.


Dick Wulff was our captain for the day. LICA members Craig Olson, Kristen Blanck, Pat Wulff and Barbara Zadeh went out on the water with limnologist Carolyn Dindorf from Fortin Consulting. 


A pitstop at the home of Bob and Annie Ibler on Lindgren Lane to look at the many zebra mussels they have found on their shoreline, mostly attached to these native clams.


Yellow Iris may be pretty but they are an invasive plant that chokes out native plants. Look for an update coming soon with information about this newest invasive.

2019 Survey Results:
Eurasian milfoil
Curly-leaf pondweed

    In the summer of 2019, LICA commissioned James Johnson of Freshwater Scientific Services to survey Lake Independence and identify the areas of the lake with the highest concentrations of Eurasian milfoil and curlyleaf pondweed. The curlyleaf pondweed survey was performed in late spring when the growth is peaking; the milfoil survey took place in the summer when the concentrations of milfoil are at their maximum. The data was collected by following a zig-zag course in the shallow areas all around the lakeshore. GPS readings were taken to pinpoint the exact location of each measurement.

    The purpose of the survey was to identify those areas where treatment would have maximum beneficial impact. But Johnson recommended to the Board that before we take any action, we develop an Aquatic Plant Management (APM) Plan that spells out our goals and objectives, to provide guidance when prioritizing future projects. There are a number of issues related to treatment plans: cost vs benefit, input from lakeshore owners, areas where treatment would be most effective, what type of herbicide to use, etc. Before drafting our APM plan, the LICA board will be surveying members for their input. We will also be working closely with experts from the
U of M, DNR and Three Rivers.

Curly-leaf Pondweed


Potential Treatment Areas

Eurasian Milfoil


Potential Treatment Areas