More than 300 dead birds have been found along the coast of the Sleeping Bear Dunes National Lakeshore this month. Biologists believe the birds are dying of botulism due to invasive species in the Great Lakes. The Watershed Center and Michigan Department of Natural Resources are asking that beach walkers who encounter dead birds on Lake Michigan contact the Botulism Network coordinator in their county:

Grand Traverse: Andy Knott, the Watershed Center, 231-941-1514
Leelanau and Benzie: Mark Breederland, Michigan Sea Grant, 231-922-4628
Leelanau~Sleeping Bear Dunes National Lakeshore: Sue Jennings, 231-326-5134
Antrim: Peg Comfort, Loon Network, 231-676-0566
Charlevoix and Emmet: Kevin Cronk, Tip of the Mitt Watershed Council, 231-347-1181

Avian botulism is thought to be caused by this cycle: invasive quagga and zebra mussels over-filter the water; sunlight is then allowed to reach farther down in the water, encouraging algae growth. Botulism grows in decaying algae mats, which is eaten by invasive round gobies. Then waterfowl eat infected round gobies and die from botulism. (Note: Bird pictured is not a shorebird.)