The Department of Natural Resources today confirmed that Type E Botulism is responsible for the deaths of ring-billed gulls and double-crested cormorants from Ludington State Park in Mason County in July. Four birds were submitted for examination and all tested positive for the disease, making this the first confirmation of 2008.

This represents the furthest south on the Lake Michigan shore that the disease has been detected in birds since 2006. The disease was first detected in shorebirds found dead on beaches in the Sleeping Bear Dunes National Lakeshore in Benzie and Leelanau counties and in the Upper Peninsula counties of Delta and Schoolcraft in 2006. For the past two years, a number of shorebirds and waterfowl have died from the disease along the northern portion of Lake Michigan.

Biologists believe the likely route of transmission of Type E Botulism in Lake Michigan, as well as in Lake Erie and Lake Ontario, probably includes Cladophora algae, invasive mussels (zebra and Quagga) and the invasive round goby. The algae establish anaerobic or low oxygen conditions in which the botulism bacterium -- found in the bottom sediments of the Great Lakes -- freely reproduces. The bacteria, and the toxin it produces, are ingested by the mussels and the mussels are in turn eaten by the gobies. Birds can become infected either by eating the mussels or fish that are sick or dead due to the botulism toxin. Also, birds may become infected by scavenging carcasses of birds or fish that have died from botulism.

Property owners along Lake Michigan who come across dead water birds should take precautions, such as making sure pets do not come in contact with wildlife carcasses. It may be necessary to have pets on leashes in areas where fish and bird die-offs are occurring. No Type E botulism illnesses have been associated with swimming along the lakeshore where fish and bird die-offs have occurred. However, pets and humans can become sick if they ingest the botulism toxin by eating a contaminated bird or fish.

Important guidelines and precautions for handling and collecting dead shorebirds developed by the Michigan Departments of Community Health, Natural Resources, and Environmental Quality should be followed. The guidelines and precautions can be found online at www.michigan.gov/emergingdiseases. The guidelines include contacting a local volunteer in each of the affected counties who will respond to inquiries and collect dead birds for examination. The names and phone numbers of the contacts in each county are available on the Michigan Emerging Diseases Web site. Persons unable to contact a local volunteer should contact the nearest DNR office or Michigan Sea Grant for assistance. More general information about Type E Botulism is available on the DNR Emerging Diseases Web site as well.