Published August 08, 2011, 12:00 AM

The nuisance next door: Invading zebra mussels make their way from Minnesota to Red River's banks

DETROIT LAKES, Minn. - Imagine the land of 10,000 lakes with nothing more than 10,000 defunct lakes – fishless, weed ridden and shores littered with hazardous sharp shells.

By: Emma Murray, INFORUM

DETROIT LAKES, Minn. - Imagine the land of 10,000 lakes with nothing more than 10,000 defunct lakes – fishless, weed ridden and shores littered with hazardous sharp shells.

All of this could happen if the expanding zebra mussel problem isn’t contained.

Zebra mussels are freshwater aquatic nuisance species (ANS) with two main stages of life: the veliger, or microscopic free-swimming stage, and the second more bothersome adult stage in which the mussels “settle down” and attach to any hard surfaces in their path. The mussels grow to about the size of a dime and can live up to eight years.

Native to Russia, the mussels first appeared in North America’s Lake St. Clair – between Ontario and Michigan – in the late 1980s. Since then the mussels have invaded lakes and rivers not only in the Great Lakes region but also as far as California.

They pillage each body of water they invade, killing your favorite freshwater entrees and causing bodily harm due to their razor-sharp shells. They are also a drain on your wallet.

Three areas of concern

Zebra mussels have three main effects: ecological, recreational and industrial. And with the adult females’ ability to produce up to 1 million eggs annually, these problems are growing at a staggering rate.

From an ecological standpoint, zebra mussels, known as filter feeders, siphon a liter of water per day to live, turning freshwater ecosystems upside down.

As they suck lakes dry, clearing the water, they are also clearing the water of food necessary for small larval fish to survive – ultimately starving the top of the food chain – the walleye, catfish and Northern pike anglers are after.

And although clear water is desirable, water that is too clear also allows sunlight to reach the bottom creating ideal conditions for the growth of ANS plants like Eurasian Watermilfoil and Flowering Rush.

Those who enjoy lakes for recreational purposes – including boating, fishing and swimming – also have reason to be concerned.

Clearer waters not only kill off fish populations leaving anglers to find a new fishing spot, but the increased number of ANS plants make water transportation difficult. Engine propellers are often tangled up in the mess of new ANS plants growing.

Zebra mussels are considered “aquatic hitchhikers” due to their tendencies to attach to hard surfaces such as boats, trailers, docks and water intake pipes in their adult stage. Their attachment to boats creates a drag on watercrafts, using more gas than usual.

And the nuisance of zebra mussels also leaves an industrial toll. The U.S. Fish and Wildlife Service estimated zebra mussels have cost Great Lakes region’s water and power plants close to $5 billion in the past decade to clear clogged intake pipes.

Annually the average cost of zebra mussel-related maintenance was estimated to be around $100 million to $200 million.

In a region tied to the land of 10,000 lakes this could spell disaster for area lake communities, and even Fargo-Moorhead, both of which rely on rivers or lakes for either ecological, recreational or industrial purposes, according to area officials fighting the spread of harmful aquatic species.

A growing problem

In 1989, the ANS made its first appearance in Minnesota’s Duluth Harbor of Lake Superior.

Nearly two decades and more than 200 miles later, they have managed to hitchhike their way as far west as Pelican Lake in Otter Tail County – a trip made possible by hitched rides on boats or into interconnected watersheds.

To top off their Minnesota conquest, they’ve now reached a new border: North Dakota’s.

Monica Zachay, a water technician for the Pelican River Watershed District, said this poses a problem for the Red River.

“If you look at the real big picture, the Pelican (River) goes into the Otter Tail watershed that eventually hits the Red River and goes north into Canada,” she said.

As a result, in July 2010, zebra mussels had hitched a ride from Pelican Lake down through the Pelican and Otter Tail rivers, washing up on the shores of the Red River.

Sightings of the “aquatic hitchhikers” in the microscopic and free swimming stage were reported in Wahpeton, near Kidder Dam – the first sighting on North Dakota shores.

Lynn Schlueter, the North Dakota Game and Fish Department’s aquatic nuisance species coordinator, said surveying the Red River this spring turned up more zebra mussels in the free swimming microscopic state, but no adult zebra mussels yet.

Schlueter said now is the time to focus on prevention measures.

“We don’t have any way of straining, filtering or keeping the microscopic items out, it can’t be done,” he said. “What we’ve got is a major waterway that has big recreation on it. With that in mind, the state has to think about keeping people that use that river well-informed of the problems of zebra mussels and how they can be prevented and the transporting can be prevented.”

Prevention measures

Luke Skinner, supervisor of the Minnesota DNR invasive species unit says there are three things the public can do to help prevent the spread of aquatic invasive species.

State officials preach the clean, drain and dry procedure for any equipment that makes contact with lake or river water.

For boats or watercrafts this is especially important as watercraft owners often travel from lake to lake, they say. Officials want recreation lake users to physically clean boats, jet skis and similar equipment, drain any water from them and let it thoroughly dry before using another lake or river.

The first step in prevention is knowing which lakes are infested, said Terry Kalil, vice president of the Becker County Coalition of Lake Associations.

Additionally, although a boat may look clean, Kalil said cleaning is still necessary as juvenile zebra mussels in the free swimming and microscopic stage of life are “invisible to the eye.”

“You have to run your fingers along the sides of the boats. Juvenile zebra mussels, when they attach, feel like sandpaper so you can’t inspect your boat visually, it has to be tactile,” she said.

Those still looking to travel from lake to lake are encouraged to take one of two extra steps to insure the boat is disinfected – power washing the watercraft with hot water or letting the watercraft air dry for at least five days in hot, dry weather before entering new waters.

Schlueter of the North Dakota Game and Fish Department says the life span of a zebra mussel out of water varies depending on a number of variables.

“Each life cycle varies in the whole thing about pointing out how long they can live,” he said. “There are some factors that make it hard to give a real good answer. It’s all based on temperature and likely humidity.”

Municipal threat

In Fargo, zebra mussels pose a threat to the city‘s water treatment plant, which treats water from the Red River.

Ron Hendricksen, plant superintendent, said the municipal plant is creating a plan with the help of Fargo’s Advanced Engineering and Environmental Services to prepare for worst case scenarios due to the zebra mussels findings.“We’ll be looking at whatever efforts will be needed to mitigate that problem,” he said.

Hendricksen said early action will prevent zebra mussel from clogging the city’s water intake pipes.

“We wouldn’t let (zebra mussels) plug the pipes up,” he said. “We just couldn’t let that happen so whatever measures we have to take will be taken.”

Just a few of the different methods proposed include installing copper-based coatings screens and using chemicals like chlorine to help stop the spread of zebra mussels.

In Minnesota, lake associations are relying heavily on education to aid in the fight against the spread of zebra mussels.

Tera Guetter, administrator of the Pelican River Watershed District in Becker County, said prevention should be taken seriously so tourism and the economic benefits it provides aren’t harmed.

It all comes down to one simple question, she said.

“If you had a choice between coming here to a zebra mussel infested lake or a non-infested lake with your children, which place would you go to?”


Readers can reach Forum reporter Emma Murray at (701) 241-5480


State laws to stave off zebra mussels’ advance

Minnesota

It’s illegal to:

  • Transport watercraft without removing the drain plug.

  • Arrive at lake access with drain plug in place.

  • Transport aquatic plants, zebra mussels or other prohibited species on all roadways.

  • Launch a watercraft with prohibited species attached.

  • Take any water away from Minnesota waters.

  • Release live bait into the water.

North Dakota

    It’s illegal to:

  • Transport all aquatic vegetation or mud.

  • Transport any waters from North Dakota. All water must be drained from boats and other watercraft, including bilges, livewells, baitwells and motors, before leaving a water body.

  • Transport live aquatic bait or aquatic vegetation into North Dakota.

  • Transport any water into North Dakota.

Zebra mussels’ three main effects:

  • Ecologically: Zebra mussels turn freshwater ecosystems upside down. Zebra mussels have the ability to filter a liter of water per day. This filter feeding takes food from other native fish, in turn killing the native fish.

    They also clear the water, allowing sunlight to more easily reach the depths of lakes and rivers, therefore creating a breeding ground of ANS plants such as Eurasian Watermilfoil and Flowering Rush.

  • Recreationally: Due to increased numbers of ANS plants, water transportation often is tangled up in the mess of new plants growing.

    Zebra mussels attached to the bottoms of boats create a drag on watercrafts, using more gas than usual.

    Their razor-sharp shells litter beaches and lakes, making these areas a hazard to be on without shoes.

  • Industrially: These effects of the mussels are the most costly of the three.

    The U.S. Fish and Wildlife Service estimated that zebra mussels have cost Great Lakes region water and power plants close to $5 billion in the past decade.

    This money was used to clear zebra mussel-clogged intake pipes for both municipal water and power plants.

    Annually the average cost of zebra mussel related maintenance was estimated to be around $100 million to $200 million.

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