June 2014

The DNR communications team works with agency experts to develop the weekly questions and provide the answers. This feature addresses current DNR issues, interesting topics, or the most frequently asked questions from around Minnesota.


Q: How many life jackets do I need in my boat, and am I required to wear one?

A: A readily accessible U.S. Coast Guard-approved life jacket is required for each person on all boats including canoes, kayaks and stand-up paddleboards. A Type IV throwable device is also required on boats 16 feet or longer.

Children under 10 years old must wear a life jacket while a boat is underway unless the child is in an enclosed cabin, aboard a passenger vessel operated by a licensed captain, or on a boat that is anchored for the purpose of swimming or diving. The life jacket also must be the appropriate size for the wearer.


Q: Does the DNR do anything to control mosquitoes?

A: The DNR does not generally do any control of mosquitoes. Mosquitoes are a nuisance to people – but they are food for a variety of animals such as fish, birds, bats and dragonflies. All mosquito control products have some level of nontarget impact to the environment, and most treatments provide only a temporary reduction in adult mosquito numbers.

We do allow very limited mosquito control at Fort Snelling State Park when levels meet certain thresholds identified in an agreement between the DNR and Metropolitan Mosquito Control District (MMCD). We also have an interagency agreement between the MN Dept. of Health, MMCD and DNR for management of disease-carrying mosquitoes.

Control treatments under both agreements occur only in localized areas within the park and only when sampling detects mosquito larva numbers above threshold levels. In many years, no treatments are conducted.

- Gary Montz, aquatic research biologist
- Ed Quinn, natural resource program consultant, Parks and Trails Division



Q: What is being done to stop the spread of emerald ash borer in Minnesota?

A: Cities with known infestations are taking infested trees down and grinding the wood for use as biofuel. The Minnesota Department of Agriculture has released stingless wasps that eat ash borer eggs and larvae. The agency also traps ash borer with guidance from the U.S. Forest Service.

The University of Minnesota is researching cold tolerance among both emerald ash borer and their parasitoids (wasps), and also exploring forest management options to maintain forest health and function after ash trees die. The DNR is working to prepare cities and townships to deal with emerald ash borer once it arrives in their communities.

The combination of these methods has kept ash borer population numbers relatively low in Minnesota and has successfully slowed the rate of spread within the state.

--Susan Burks, DNR invasive species program coordinator



Q: What are the reasons for removing dams, and what role does the DNR play in this process?

A: Some older dams no longer provide sufficient benefits to compensate for their public safety hazards, environmental damages, or repair and maintenance costs. In these cases, the state may provide grants for removal. Removing or altering these dams can restore stream function and stability, improve water quality, increase property values, and reduce drowning risks associated with the dams.

The DNR gets involved with permitting, project development and funding of dam removals, depending on who owns the dam. DNR engineers identify dams that pose a safety hazard, and DNR biologists identify dams that have a critical impact on fish and wildlife populations.

--Jason Boyle, state dam safety engineer


Q: Is there commercial fishing in Minnesota?

A: Commercial fishing in Minnesota for walleye and other game fish was eliminated in 1983. Today, commercial harvest is mostly limited to rough fish such as common carp, buffalo and freshwater drum. These fish are harvested primarily using large seine nets up to 3,000 feet long and 20 feet deep.

On Lake Superior, the DNR issues a maximum of 25 commercial licenses each year. The main harvest on Superior is ciscoes, also called lake herring, with some permitted harvest of whitefish and lake trout. Commercial fishing on Lake Superior is primarily done with gillnets.

On average, Minnesota’s commercial harvest each year is about 4.5 million pounds of fish, valued at close to $1 million. 

--Neil Vanderbosch, fisheries program consultant



DNR Question of the Week Archive