EMPIRE, Mich. – A “large number” of shorebirds were found dead at Sleeping Bear Dunes National Lakeshore last weekend.
Park officials believe avian botulism is the cause of death for the birds. They are believed to have died from an outbreak of type-E botulism. Outbreaks of avian botulism have been occurring in the Great Lakes region since at least the 1960s and the severity ranges from year to year.
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Spores of type E botulism are found naturally in the environment, but the toxin is only produced when conditions allow spore germination and cell growth. The toxin is a neurotoxin and causes paralysis. It is usually fatal.
It is believed that the invasion of dreissenid mussels created conditions that help native green algae grow. As water warms and algae decay at the bottom, anaerobic conditions develop and the bacteria produce the toxin. The toxin is eaten by the invasive round goby and other fish that feed on plankton. Birds get sick by eating contaminated fish or by scavenging dead birds that died from the toxin.
Visitors are being reminded to never touch wildlife. In fact, it’s illegal for civilians to handle wildlife at Sleeping Bear Dunes. If you find sick, injured, or dead wildlife you should notify park officials. If possible, write down the latitude and longitude coordinates when reporting.