Get all your fishing information here, including rules and regulations, license info, the weekly fishing report and much more. Use the link above to visit the fishing home page, or go directly to your area of interest below:
Get all your hunting information here, including hunting season dates, rules and regulations, and much more. Use the button above to visit the hunting home page, or go directly to your area of interest below:
Information on DNR shooting and archery ranges, rules and regulations, resources to get started and more. Use the button above to visit the target shooing and archery home page, or go directly to one of the pages below:
Find snowmobile trail permit info, maps, rules and regulations and more. USE THE BUTTON ABOVE TO VISIT THE SNOWMOBILE HOMEPAGE or go directly to you area of interest below:
Want to find tasty morel mushrooms in the forest? Click the box above for tips and tricks to fill your basket.
Find cross-country ski, ice fishing , snowmobiling info and much more.
Find facility info, overnight info, an event calendar and much more.
Find a great trail experience near you - whether you want to hike, bike, snowmobile or ride an ORV. From long, paved linear trails to rugged forest terrain, Michigan offers trail opportunities for all abilities and interests.
Visitor Centers across the state provide education programs, field trips, archery, fishing, trails and much more. Click the box above to see all our locations, or click the individual location below.
We administer grants that enable our local partners to promote the lifestyles we all enjoy by providing recreational opportunities, enhancing wildlife habitat and ensuring public safety. Visit the grants home page by clicking on the button above, or view a specific area of interest below:
Recreational Safety and Hunter Education
Learn about Michigan's diverse range of fish, plants, trees, reptiles, amphibians, insects and mammals. Click the box above to see all species, or click the species group below.
DNR educators across the state provide fun, educational activities, programs and workshops year-round for adults, families and kids. Click the box above to see all our offerings, or click the program below.
DNR educators provide classroom lessons, field trip opportunities, professional development and experiential programs to teachers around the state. Click the box above to see all our offerings, or click the program below.
DNR forest resources professionals maintain healthy forests, manage wildfire, maintain responsible harvesting certifications and improve wildlife habitat. Click the box above to learn more about Michigan's state forests.
All DNR-related boards, committees, and advisory groups
Find seasonal, part-time and full-time job openings with the DNR
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Mercury is an extremely toxic element; however only occasional poisoning cases have been reported. It has been used in the past as the active ingredient in ointments, parasiticidals, antiseptics, disinfectants, diuretics, and fungicides. Mercury can be a source of environmental contamination when present in seed dressing fungicides, anti-slime fungicides in pulp and paper industries, by-products of burning coal, mine tailings, and wastes from chlorine-alkali industries. Whatever the source, mercury finds its way into water sources and accumulates in fish and fish-eating animals. Inorganic mercury which enters a water source is readily converted to methyl mercury by aquatic microorganisms and accumulates in the tissues of fish. In Michigan, the bald eagle, great blue heron, common loon, mink, otter, common merganser (possible), and common goldeneye (possible) have been poisoned by mercury as a result of ingestion of mercury contaminated fish. Waterfowl may be exposed to chronic low levels of mercury present as an environmental contaminant. Mercury, which is eliminated from the female via egg laying, has been reported to cause abnormal egg laying behavior, impaired reproduction, slowed duckling growth, and altered duckling behavior in mallard ducks. Occasionally seed eating birds are affected by mercury toxicity after feeding on mercury fungicide treated seed.
Ingested mercury is rapidly absorbed by the intestinal tract and stored in the kidney and liver. Once absorbed, mercury is slowly eliminated in the urine, feces, saliva, sweat and milk.
Depending upon the amount of mercury ingested, the clinical signs can either be peracute, acute, or chronic. Ingestion of large amounts of mercury results in almost immediate death due to heart attack. Symptoms of acute poisoning include severe abdominal pains, vomiting and diarrhea. The
intestinal mucosa is destroyed and if the animal survives this first stage, hemorrhagic gastroenteritis is followed by ulcerative colitis with destruction of the kidney tubules. Chronic exposure results in soreness, swelling, bleeding and ulceration of the gums, tongue and oral mucosa with anemia, edema, and body wasting ending in death. Chronic mercury poisoning may be accompanied by mental disturbances due to degeneration of nerve tracts and may result in blindness, weakness, incoordination, and coma.
Mercury poisoning is suspected from clinical signs and history of exposure to mercury contamination. Definitive diagnosis can be made by detection of high levels of mercury in the stomach contents, kidneys, and/or liver.
Absorption from the gut is so rapid that treatment of wildlife is usually not practical. When treatment is possible, the stomach should be emptied, and milk or raw egg white given to precipitate the mercury. Dimercaprol (BAL) is the treatment of choice accompanied by the administration of large amounts of intravenous fluids to prevent dehydration.
Control of mercury poisoning in wildlife is aimed at reducing the presence of mercury as an environmental contaminant. Humans are susceptible to the toxic effects of mercury and have been poisoned due to the consumption of mercury contaminated fish and shellfish. Although wildlife deaths due to mercury poisoning are rare, there is a possibility that mercury may reduce populations by decreasing reproductive efficiency.
