Dead loons are washing up on Benzie and Leelanau County beaches, a grisly scene experts attribute to avian botulism.
Lynette Grimes found 99 dead loons on a stretch of Benzie County beach Tuesday evening in the Sleeping Bear Dunes National Lakeshore.
"It's devastating," said Grimes, who volunteers on an avian botulism task force organized by the National Park Service.
"The loons are washing up regularly right now," she said. "I imagine the other volunteers are just as devastated as we are about what we are encountering. It looked like a bomb went off. The beach was littered with carcasses."
Volunteer Robert Lowing encountered a similar situation Tuesday night in a one-mile stretch of Benzie County beach. He buried 83 dead loons.
"It was nightmarish," said Lowing. "I looked down the beach and there were whole clusters of loons. No sick birds. Just all dead — freshly dead."
The suspected culprit is avian botulism. Botulism spores are native to the Great Lakes, and when conditions are right, the spores germinate and grow toxin-producing bacterial cells. It is believed the birds eat fish contaminated with the toxin.
Mark Breederland is an educator with the Michigan Sea Grant Extension in Traverse City. He said bird carcasses in the area tested positive for avian botulism. Dying birds include the common loon, several grebe species, the double crested cormorant, long-tailed ducks and white winged scoters.
"The calls started after (weekend) rains and winds," Breederland said.
More than 10,000 birds died on Lake Michigan from avian botulism in 2006 and 2007.
There are no reported cases this year of bird deaths due to avian botulism on Grand Traverse Bay, said Andy Knott, executive director of the Watershed Center Grand Traverse Bay.
Grimes said she was saddened by all of the bird deaths but is proud she is helping by burying the birds and preventing additional botulism cases.
"It was back-breaking work, but so necessary to take care of this immediately because other birds start eating the carcasses and the botulism is spread further," Grimes said.