The remains of thousands of dead gulls, loons, mergansers and other migratory birds have inexplicably washed onto the shores of Lake Michigan for years. Now some scientists are claiming they know the answer..
Over the last 11 years, estimates say over 100,000 birds have died off in a strange manner. This year, the die-off is expected to kill more birds than this summer’s oil spill in the Gulf of Mexico, and seems to have spiked again after two years with a low death rate.
The first relatively large dead bird count was recorded in 1999 by researchers who found when 311 bird carcasses off the shores of Lake Erie. In 2000, 8,000 birds were recorded throughout the Great Lakes region, and since then the death count has been in the thousands every year since.
A new theory to explain the bird deaths suggest the rise of zebra and quagga mussels, two invasive species in the Great Lakes that have caused many problems in the area already, have inadvertently caused the birds to die because of the chemicals the organisms take into their systems.
Both types of mussels filter botulism and other naturally occurring toxins from the waters of the Great Lakes. Round gobies then eat the mussels, which are in turn eaten by the birds. The toxins collected by the mussels could be the reason so many birds have fallen victim to an untimely death.
Organizations studying the issue include Michigan’s Department of Natural Resources and Environment, or DNRE, Common Coast Research and Conservation, the USGS and the National Wildlife Health Center.
Many biologists recognize the issue, but aren’t sure what should be done. The general consensus is to continue studying the problem and see if it stops, but there are people who think that’s not enough.
A number of the species affected by the die-off are protected bird species in the state of Michigan, including the common loon. The common loon is a threatened species, and some researchers hope the loss of a significant number of the birds will draw attention to the issue and garner funding to attempt to fight it.