Tip of the Mitt Watershed Council
Skip Navigation LinksHome > Learn > Avian Botulism


What is Avian Botulism

Loons, scoters, grebes, and piping plovers are among thousands of birds found dead on the Lake Michigan shoreline in recent years. Type E botulism has been confirmed as the cause of death by the Michigan Department of Natural Resources (MDNR) in bird carcasses collected from numerous locations along the Lake Michigan shoreline. Each fall, reports of dead birds from Grand Traverse Bay to Sturgeon Bay are phoned in to the Tip of the Mitt Watershed Council office, where staff respond and work with Michigan Sea Grant and the MDNR to track bird and fish fatalities in affected areas.

"This is a tragic loss of birds that we in Northern Michigan have come to identify with" commented Kevin Cronk, Monitoring and Research Director at Tip of the Mitt Watershed Council. Cronk added that "we are deeply concerned about this situation and the number of problems plaguing the Lake Michigan ecosystem." In regards to Watershed Council response to the bird kills, Cronk explains that "when we get calls about dead birds, we inquire into and record relevant information, such as the number and type of birds, but we also take the opportunity to educate the public about avian botulism and precautions that should be taken.”

According to the MDNR, botulism is a "paralytic condition brought on by the consumption of a naturally occurring toxin produced by the bacterium Clostridium botulinum." Type E botulism is found in anaerobic (or low oxygen) environments, such as lake sediments, where it is taken in by fish. Affected fish experience a loss of equilibrium and exhibit unusual behavior such as swimming erratically or floating near the surface. These fish become easy targets and birds feeding on dead or dying fish are in turn affected. Great Lakes fish that have been affected by botulism include freshwater drum, smallmouth bass, rock bass, stonecats, round gobies, channel catfish, alewives and sturgeon.

Avian botulism was first documented in the Great Lakes in the 1960's, but there were no confirmed cases in Lake Michigan between 1983 and 2006. Following this decades-long hiatus, botulism returned with vehemence, taking a heavy toll on migratory waterfowl with nearly 3000 dead birds reported from just Sleeping Bear Dunes National Park in 2006 and an estimated 8,000 dead birds turning up on the northern Lake Michigan shoreline in 2007. During the relatively cool summers of 2008 and 2009 with Great Lakes’ water levels rising slightly, the incidence of avian botulism dropped dramatically and few dead birds were reported. Unfortunately, the quiet was not to last. Scores of dead birds began to appear again on the northern shores of Lake Michigan in the fall of 2010, following a summer of warmer temperatures and a return to lower water levels.

Although uncertain, recent outbreaks may be linked to lake ecosystem disruptions caused by low lake levels and aquatic invasive species, such as the zebra mussel and round goby. The bird kills also occur in waves, depending upon environmental conditions. Recent die offs on the Lake Michigan shoreline are believed to be the result of autumnal changes in the lake ecosystem combined with the fact that a great number of birds are migrating through the region. The current outbreak poses little danger to people since most bird species affected are not typically eaten by people and thorough cooking destroys the toxin. However, Cronk advises that "everyone take precautions if handling dead birds by using disposable gloves and washing thoroughly afterward." Cronk also warns that "anglers and hunters should avoid fish and waterfowl that are easy pickings due to strange behavior, such as lethargy and erratic swimming" and that "all fish and game should be cooked thoroughly so as not to take any chances".

Historic Outbreaks of Avian Botulism


What you can do:

Remove dead birds and fish immediately, to prevent the spread of botulism, as the bacteria in the carcasses can serve as the source of outbreaks for months. Please review the following guidelines for handling carcasses and monitoring your beach area:

  • DO NOT handle dead fish or birds with your bare hands
  • Properly dispose of carcasses by double bagging and placing them in the trash
  • Beware of fish that are floating - if they are not fighting, they are likely not healthy and should not be consumed
  • Do not eat undercooked or improperly prepared fish or waterfowl
  • Hunters should never harvest birds that appear to be sick or are dying
  • Do not let your pets eat dead fish or birds
  • Look for carcasses at two peak times: in mid-late summer and in the fall and follow proper disposal methods
  • Assist with monitoring efforts. Contact Kevin Cronk at 231-347-1181 to volunteer and help track the number and type of birds

Resources for Volunteer Beach Rangers and Concerned Citizens

Botulism has been identified as a problem for fish and birds in Lakes Ontario, Erie, and Michigan. For more information about avian botulism in the Great Lakes visit the links below.

Volunteer Avian Botulism Monitoring (Beach Ranger) Guide and Forms

Avian Botulism Monitoring Form
Avian Botulism Monitoring Guide

Additional Resources

Avian Botulism 2012 Report Emmet and Charlevoix County

Avian Botulism Monitoring - 2012 Report for Emmet and Charlevoix Counties

Since 2007, Tip of the Mitt Watershed Council has taken the lead to coordinate avian botulism monitoring in the Northern Lower Peninsula in an effort to better understand the underlying factors contributing to outbreaks. In the fall of 2012, the Watershed Council continued working with the Emmet County Lakeshore association (ECLA) and community volunteers to monitor outbreaks of avian botulism along the Lake Michigan shoreline in Emmet and Charlevoix counties. This is a report of their findings.

Click here to READ ONLINE

Click here to DOWNLOAD a pdf.
Botulism, Aquatic Invasives, Algae, Presentation, Tip of the Mitt Watershed Council

Botulism, Algae, and Invasives

Powerpoint presentation slides in a pdf format.

Tip of the Mitt Watershed Council's presentation on avian botulism. This file is 2MB in size. For more information about the presentation, please contact Kevin Cronk at (231) 347-1181 or e-mail at kevin@watershedcouncil.org.

CLICK HERE to download the presentation.

Beached Bird Guide for Northern Lake Michigan

Beached Bird Guide for Northern Lake Michigan

Prepared by Common Coast Research & Conservation
In association with the Grand Traverse Bay Botulism Network
© 2008 Common Coast Research & Conservation

This guide was developed to aid with the field identification of the most common waterbird species implicated in botulism E die-offs on northern Lake Michigan.

CLICK HERE to download this publication.
SeaGrant Fact Sheet, Avian Botulism, 2003

Botulism Fact Sheet

Sea Grant - Pennsylvania
Revised December 2003
This fact sheet was modified by Sea Grant Pennsylvania with permission of U.S.G.S.

CLICK HERE to download this publication.
Wildlife Heath Event Reporter

Great Lakes Restoration Initiative

Wildlife Health Event Reporter

An online tool for the general public and volunteer groups to record environmental and wildlife health events around the Great Lakes.

With the input of members from the Great Lakes Botulism Coordination Network (GLBCN) organized by the US Environmental Protection Agency, this new citizen science application, GLRI-WHER, was launched and made available online at http://glri.wher.org.

CLICK HERE to download this publication.
AMBLE Ramble Newsletter, Avian Botulism

AMBLE Ramble Newsletter

The primary audience for this newsletter is AMBLE (Avian Monitoring for Botulism Lakeshore Events) volunteers. It includes findings with regard to bird mortality and avian botulism along Door County beaches during the summer of 2011. For more information or to participate in future AMBLE events in Door County contact Jenny Chipault by e-mail at AMBLE@usgs.gov or by phone at 608-270-2473.

Tip of the Mitt Watershed Council • 426 Bay Street, Petoskey, MI 49770
PH: (231) 347-1181 • Fax: (231) 347-5928 • www.watershedcouncil.org
Copyright © 2015 by Tip of the Mitt Watershed Council. All rights reserved. SiteMap
Powered by SiteChalk