|
| |
|
| |
|
|
|
12/29/2006Newsmakers 2006Bird die-off raised concerns
A dead grebe lies partially buried in the sand along the Lake Michigan coastline at Peterson Road Beach in the Sleeping Bear Dunes National Lake Shore. The National Park Service said a Type E botulism outbreak killed an estimated 2,900 water birds since August. Click here for more photos. EMPIRE — Biologists said this summer's massive die-off of birds in the Sleeping Bear Dunes National Lakeshore signaled a shift in the Great Lakes ecosystem. Tests conducted by the Michigan Department of Natural Resources determined that Type E botulism killed an estimated 2,900 birds at the park since August. The dead birds washed up on the Lake Michigan shoreline, prompting a flurry of calls from residents concerned about the cause. The outbreak was the topic of a seminar sponsored in November by the Inland Seas Education Association in Suttons Bay. Todd Morgan, facility management specialist at Sleeping Bear, said it is too soon to tell whether measures can be taken to prevent a similar outbreak in 2007. The park's natural resources division is still analyzing data to determine the next step. "They are making contact with other agencies around the Great Lakes to see how widespread it is,” Morgan said. "I would still put it in the monitoring phase.” The outbreak primarily impacted fish-eating birds, including common loons, cormorants, gulls, horned grebes and mergansers. Bird die-offs caused by Type E botulism were first reported on Lake Michigan in 1963 and have become common in shoreline locations across the Great Lakes. Outbreaks often are related to turnover of lake bottom sediments containing the botulism-causing bacteria that are ingested by fish that die and then poison birds that eat them. Ken Hyde, a biologist at Sleeping Bear, warned that such outbreaks could become more common as non-native species continue to invade the Great Lakes. He suspected that zebra mussels and round gobies, both invasive species, contributed to this summer's outbreak by concentrating the botulism. See related items:
|
|
