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Aquatic Invasive Species

Introducing non-native species into Iowa waters can upset the balance of the ecosystem, hurting the environment. Aquatic nuisance species (Eurasian Milfoil, Zebra Mussels, Asian Carp, etc.) are most often spread between waterways by hitching a ride on boats and trailers. When transplanted into new waters, these organisms proliferate, displacing native species and damaging the water resource.     


Eurasian Watermilfoil

In nutrient-rich lakes, Eurasian watermilfoil can form thick underwater stands of tangled stems and vast mats of vegetation at the water's surface. In shallow areas, the plant can interfere with water recreation such as boating, fishing, and swimming. The plant's floating canopy can also crowd out important native water plants.  

Milfoil is found in waters less than 20-feet deep. It may form mats in waters less than 15-feet deep. A native look-alike northern watermilfoil has fewer (5-10) leaflet pairs.

A key factor in the plant's success is its ability to reproduce through stem fragmentation and underground runners. A single segment of stem and leaves can take root and form a new colony.  Fragments clinging to boats and trailers can spread the plant from lake to lake. The mechanical clearing of weed beds for beaches, docks, and landings creates thousands of new stem fragments that can drift with the wind. Removing native vegetation creates perfect habitat for invading Eurasian watermilfoil.


Zebra Mussels

Zebra mussels are small clam-like animals about the size of your fingernail - when fully grown. Zebra mussels have multiple stripes that give them their "zebra" name and are shaped like the letter "D". Zebra Mussels are very fast growing with sharp edges that cut swimmers' feet. Zebras can also clog water intake pipes. (All of the residents in the watershed draw their drinking water from the Iowa Great lakes.)

Zebra mussels are present in nearly all lakes in the Iowa Great Lakes.

For additional Information Local Zebra Mussels CLICK HERE

Silver Carp USGS.jpg
silver carp IL.jpg

Asian Carp - Silver & Bighead

Bighead and silver carp are two species of Asian Carp that impact Iowa's waters. Silver carp can jump above the water as boats drive by, injuring boaters, tubers, and water skiers.  This species can grow to be three feet long and weigh up to sixty pounds. Bighead carp can reach sizes up to five feet long and ninety pounds. Both species complete with native species for food and space.

Both bighead and silver Asian carp are in the Missouri River - while bighead and silver carp have found their way up the Little Sioux River. In August 2011 bighead Asian carp were found in East Okoboji near the "narrows". In September 2011 Silver Asian Carp were found in Elk Lake and Lost Island Lake near Ruthven - just 15 miles from the Iowa Great Lakes.


Video of silver Asian carp

In December 2012 an Electric Fish Barrier was completed at the Lower Gar Outlet to prevent the further migration of Asian Carp into the Iowa Great Lakes.


Boaters should follow a simple set of procedures each time when leaving the water:

  • Remove any visible plants, fish, or animals before transporting equipment

  • Drain water from all equipment (motor, livewell, bilge, transom well) before transporting

  • Clean and dry anything that comes into contact with water (boats, trailers, equipment, boots, clothing, dogs).

  • Before moving to another waterbody either:

  • Rinse your boat and equipment with hot (104 degree) water; or

  • Spray your boat and trailer with a high pressure water at a car wash; or

  • Dry your boat and equipment for at least 5 days

  • Never release plants, fish, or animals into a waterbody unless they came out of that waterbody. Empty unwanted bait in the trash

  • Learn to identify aquatic invasive species. Report any suspected infestations to the nearest DNR fisheries station.

If a boat, motor, trailer, live well, etc. have been out of the water for a considerable length of time  (Five days minimum – ten days better) any AIS should have died. To be sure, everything should be washed with hot water and allowed to dry before entering the lake.

It is illegal in Iowa to:


  1. Transport Aquatic Invasive Species on a public road.

  2. Place a trailer or launch a watercraft with Aquatic Invasive Species attached in public waters.

  3. Operate a watercraft in a marked Aquatic Invasive Species area.

  4. The penalty for violating this law is a $500 fine plus costs.

According to Iowa law, the DNR may prohibit boating, fishing, swimming, and trapping in infested bodies of water.


The Electric Fish Barrier Is Operating

The electric fish barrier at the Lower Gar outlet is activated and is protecting the Iowa Great Lakes from Asian carp. It is located on 230th Avenue East of Highway 71. The new fish barrier shows a caution flashing light when activated. Although the electricity level used is not fatal to humans or fish, it’s recommended that people do not go around the fence.


Boat Ramp AIS Educator Program | Iowa Great Lakes

The economic impact to the Iowa Great Lakes if our lakes were infested with Eurasian watermilfoil or zebra mussels is tremendous. The Water Safety Safety Council, lake protective associations, and the DNR have used many communications tools to educate the boating public: highway billboards, cable television, newspaper articles, local radio stations, boat ramp kiosks, and boater's maps to educate the public about AIS.

Our Aquatic Invasive Species experience has taught us the most effective way to communicate the AIS message is by direct face-to-face contact on the boat ramp. With 12 major boat ramps in Dickinson County providing daylight coverage on weekends is a challenge. More than ten years ago the Water Safety Council and the Iowa Department of Natural Resources tried to recruit volunteers to educate boaters at the boat ramps in the Iowa Great Lakes area. For the first few years, we had sufficient volunteers from the lakes community. Slowly the numbers of volunteers began to wane. Until this year funding for the boat, ramp educators was provided by a grant from the Dickinson County Water Quality Commission.

View the AIS Boat Ramp Volunteer Training Video - 12:31

                         PART 1  CLICK HERE                PART 2  CLICK HERE

AIS Information Takes To The Air

Communicating Aquatic Invasive Species information to boaters coming into the Iowa Great Lakes area has been a challenge. Many boaters are visiting our chain of lakes for the first time or only visit our lakes once a year. It is important that we communicate that boaters should drain, inspect, and clean their boats and trailers before launching.

In 2010 the DNR launched an Information Radio System to inform boaters about the threat of Aquatic Invasive Species. You may have encountered these stations at airports, tourist attractions, and for road construction. The new radio system has been licensed to operate at 1640 KHz. on the AM broadcast radio band.

The Iowa and Dickinson County Highway Departments have installed roadway information signs to alert boaters to this new AIS radio broadcast. Funding for this new broadcast system was provided by the Dickinson County Water Quality Commission.

Highway 9W Sign State 2010 Apr 233.JPG
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