April 2006

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.






What is the DNR doing in the vicinity of the cattle herds where bovine tuberculosis was discovered?

During the 2005 firearms season, only one of the 473 lymph node samples collected from hunter-harvested deer tested positive for bovine tuberculosis (TB). An additional 80 deer were tested over the winter, revealing one more infected deer. The collection areas were near the bovine TB-infected cattle farms in Beltrami, Lake of the Woods, Marshall and Roseau counties. Genetic testing of the infected deer revealed the same strain of bovine TB discovered in cattle. This strain is known to occur in Mexico, making it likely the disease spilled over from cattle to deer in the vicinity of the infected farms. These findings suggest the occurrence of bovine TB in the deer population is extremely low. The DNR continues to monitor wild deer, working closely with the Minnesota Board of Animal Health (BAH) and U.S. Department of Agriculture in these areas to minimize or eliminate the potential for the disease to spread. Cattle owners living within a 10-mile radius of the infected cattle farms are required by the BAH to have all of their cattle tested for the disease. The two agencies are also recommending cattle from farms within an additional five-mile radius be checked for bovine TB. The DNR issued several deer shooting permits to cattle farmers in the immediate vicinity of the infected farms, and will continue to work with the agricultural community to obtain TB-free accredited status.

Lou Cornicelli, DNR Big Game Program coordinator


As the snow melts in the spring, and during lengthy periods without rainfall, the DNR issues fire restrictions. Is there a difference between a restriction and burning ban?

Burning restrictions involve the issuing of burning permits. Burning permits are required for running fires, such as a grassy ditch or field, or piled vegetative debris. When restrictions are in place, permits are only issued for management or prescribed burns, or special burns such as construction companies burning trees and brush cleared from roads. Burning bans, which are issued by the DNR commissioner, prohibit other types of fires. For example, bans may disallow campfires completely or restrict them to certain hours of the day. They may also restrict any fire outdoors, including smoking and barbeque grills. Bans are only imposed when extreme fire conditions have existed for a long period of time.

Jean Bergerson, Minnesota Interagency Fire Center information officer


Water quality is important to all of us. Are there any simple things people can do to help keep our lakes, rivers and wetlands healthy?

Removing trash along a riverbank, lakeshore or from a wetland is that step in the right direction. Through the DNR's Adopt-a-River program, people can sign up to "adopt" a section of a lake, river or wetland to ensure its long-term health through annual cleanups. Volunteers choose their own site from shorelines that have not yet been adopted. The program supplies "how-to" assistance, free rubbish bags, gloves and recognition after a reporting of cleanup results. The program, which began in the mid-1980s, was founded to clean up the state's designated canoe and boating routes. These areas had sustained considerable abuse as dumping areas. Since the program's first year in 1989, 2,100 cleanups have removed more than 4.7 million pounds of trash from more than 7,300 miles of shoreline, ravines and floodplains. For more information on the Adopt-a-River program, visit the DNR's Web site at www.dnr.state.mn.us/adoptriver.

Paul Nordell, Adopt-a-River Program coordinator


It's not uncommon for lakeshore property owners to return to their cabins in the spring to find damage to their shoreline, docks and boat lifts bent, retaining walls and sometimes to the cabins themselves. What causes this?

This type of property damage is caused by "ice heaving" or "ice jacking." As ice freezes and thaws, cracks form because of the different contraction rates at the top and bottom of the ice sheet. This is especially true in years when there's a lack of insulating snow cover, which means our current conditions this year may result in a lot of property damage around the state. When the water rises in the cracks and freezes, the ice sheet expands slightly. Rising air temperatures warms the ice, which causes the additional expansion to exert a tremendous thrust against the shore. This powerful natural force forms a feature along the shoreline known as an ice ridge. These ridges can sometimes reach as high as five feet or more. Additional warming and cooling of an ice sheet can cause additional pushing action that possess enough power to nudge bridge masonry piers out of plumb and push houses off their foundations.

Glen Yakel, DNR Division of Waters Hydrographics supervisor


DNR Question of the Week Archive