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Aquatic Invasive Species (AIS)

Why should we be concerned about AIS?

We're being invaded by this!
And this!
And this!
And many more!!

1. Economic Impact

Our lake ecosystems provide us with many services including fisheries, water purification, recreation/tourism, and nutrient recycling. AIS invariably disturb those services with negative effect on the strength of the local economy.
A. Reduced Property values
Nobody wants to swim, canoe, or motor in water filled with weeds or walk on a beach littered with razor-sharp shells. And it is unsightly as well. As a result, property values are expected to drop by at least 17% when AIS infests a body of water, based on the experience of other lake communities (1a). In practical terms, this means that a lake with 200 properties, each valued at $200,000, could suffer a total reduction in property values of $6,800,000.
B. Reduced Tourism Income and Employment
AIS destroy the habitat of native game fish and thereby destroy any local economy dependent on a healthy fishery. For example, it is estimated that the invasive zebra mussels and spiny waterfleas together now filter every gallon of water in Mille Lacs every day (1b). No wonder the walleye population in Mille Lacs has crashed, taking the local economy down with it. Some resorts have seen occupancy drop by 60 percent in the last few years. Mille Lacs county has asked state lawmakers to support an economic relief program that could cost Minnesota taxpayers $10 million annually for three years (1c). Imagine the economic turmoil as zebra mussels and spiny waterfleas march across the rest of Minnesota. Of course, the walleye crash had several causes (overfishing, warmer water) but DNR data make it clear that this dynamic duo of AIS is destroying the fish food chain.

2. Loss of lake recreational use and aesthetics.

As can be seen in the videos above, AIS quickly and permanently disrupt normal recreational use of our lakes. They have no natural predators on site so they so simply take over. It is no fun to swim, fish, sail, canoe, or motor in infested areas. Sometimes, they are downright dangerous to human health as described below.

When AIS invade our lakes and rivers, they will each have different destructive effects. Here are four major species:

A. Starry stonewort:
B. Eurasian Milfoil:
milfoil mat on lake milfoil wrapped around boat propeller
C. Zebra and Quagga Mussels
Graph of effect of air temperature and relative humidity on killing zebra mussels
zebra mussels encrusting boat propellerzebra mussel relative size to a US quarter coin
D. Spiny Waterfleas
spiny waterfleas on fishing line spiny waterflea magnified
E. Many other AIS scourges

Eurasian milfoil, zebra mussels, and spiny waterfleas alone will significantly degrade our property values. Even so, there are many other plant and animal non-native species that are a threat to the economy. The MN DNR uses a four-tiered system to classify invasive species:

Here is the complete list of aquatic invasive prohibited* and regulated** plants in Minnesota (with photo attributions at bottom of page):

Robert Vidéki, Doronicum Kft.,
Ashley Basil, Wikipedia
Wisconsin DNR
Minnesota DNR
Leslie J. Mehrhoff, University of Connecticut,
James H. Miller, USDA Forest Service,
Chris Evans, University of Illinois,
Leslie J. Mehrhoff, University of Connecticut,
Barry Rice,,
Leslie J. Mehrhoff, University of Connecticut,
Robert Vidéki, Doronicum Kft.,
Chris Evans, University of Illinois,
Nancy Loewenstein, Auburn University,
Linda Wilson, University of Idaho,
Rob Routledge, Sault College,
Minnesota DNR
John M. Randall, The Nature Conservancy,
Josh Hillman,,
Joy Viola, Northeastern University,
Charles T. Bryson, USDA ARS,
Leslie J. Mehrhoff, University of Connecticut,

Here is a partial list of aquatic invasive prohibited and regulated animals in Minnesota:

3. AIS Reach

AIS have penetrated deep into the heart of Minnesota, nearer and nearer to the magnificent headwaters of the Mississippi River. Zebra mussels, starry stonewort, Eurasian milfoil, faucet snails, and banded mystery snails are within 60 miles of this national treasure (20).

4. Method of Spreading

Several studies show that it is human boating practices, not bird behavior, that is responsible for the spread of AIS (21, 22). For example, one study conducted on Lake St. Clair in Wisconsin (22) showed that mallard ducks transported on average less than one zebra mussel larva per trip as they left the lake which is infested with zebra mussels. At the same time, most boats examined on Lake St. Clair had an average of 4200 zebra mussel larvae in each of their 9 gal live-well systems.

5. AIS detection

Transporting many AIS is illegal (23) but no one can realistically inspect every inch of their boat hull looking for grain-sized zebra mussels or get down on their knees and look for specks of milfoil.

6. Many different personalities and ideas

All Minnesotans love our lakes and rivers and there is a wide spectrum of concern on throughout the state about the threat of AIS. Some feel it is overblown. Others are worried to the point of trying to stop development of new launches. Some are concerned but do not have the time, money, or training to get involved.

7. Decontamination

"Clean, Drain, Dry" is the motto of the DNR when it comes to controlling AIS. However, these three seemingly simply instructions are extremely difficult to carry out. Killing/removing AIS is difficult, time-consuming, and costly as discussed above. All equipment must be decontaminated and includes but is not limited to: docks, trailers, hulls, INTERNAL water cooling systems, bilges, livewells, anchors, mooring and anchor lines, inflatables, downriggers, planing boards, water skis, wakeboards, ropes, fishing gear, bait buckets, and stringers (23).

Places on watercraft where aquatic invasive species may lodge

8. Penalties

The penalty for introducing AIS into a Minnesota lake is not commensurate with the violation. For example, if an uncaring or uninformed individual transports AIS to a lake with 200 properties, each valued at $200,000, the total reduction in property values could reach $6,800,000. However, the penalty is only $500 "for placing or attempting to place into waters of the state water-related equipment that has prohibited invasive species attached when the waters are not listed by the commissioner as being infested with that invasive species". (24).

9. Training

It is impossible to adequately train 100% of all Minnesota water users on all types of AIS. Even if this were possible, the knowledge, skill, and dexterity needed for decontamination render the exercise unrealistic.

10. Summary

11. References

Economic Impact

Starry stonewort

Eurasian Milfoil

Zebra Mussels

Spiny Waterfleas

AIS transport

AIS Links

lake and shore

MN COLA serves to coordinate the efforts of all lake, river, and watershed associations in Minnesota, related to shoreline preservation and restoration, water quality, prevention of aquatic invasive species (AIS), and sustainable uses and development for bodies of water in all counties, which include: Aitkin, Anoka, Becker, Beltrami, Benton, Big Stone, Blue Earth, Brown, Carlton, Carver, Cass, Chippewa, Chisago, Clay, Clearwater, Cook, Cottonwood, Crow Wing, Dakota, Dodge, Douglas, Faribault, Fillmore, Freeborn, Goodhue, Grant, Hennepin, Houston, Hubbard, Isanti, Itasca, Jackson, Kanabec, Kandiyohi, Kittson, Koochiching, Lac Qui Parle, Lake, Lake Of The Wood, Le Sueur, Lincoln, Lyon, Mahnomen, Marshall, Martin, McLeod, Meeker, Mille Lacs, Morrison, Mower, Murray, Nicollet, Nobles, Norman, Olmsted, Otter Tail, Pennington, Pine, Pipestone, Polk, Pope, Ramsey, Red Lake, Redwood, Renville, Rice, Rock, Roseau, St. Louis, Scott, Sherburne, Sibley, Stearns, Steele, Stevens, Swift, Todd, Traverse, Wabasha, Wadena, Waseca, Washington, Watonwan, Wilkin, Winona, Wright, and Yellow Medicine.

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Minnesota Coalition of Lake Associations

Web design, Curtiss Hunt; masthead photo, Kathyrn Jonsrud; footer photo, Amanda Weberg.