Invasive mussels causing massive ecological changes in Great Lakes

ANN ARBOR, Mich.—The ongoing spread of non-native mussels in the Great Lakes has caused "massive, ecosystem-wide changes" throughout lakes Michigan and Huron, two of the planet's largest freshwater lakes, according to a new University of Michigan-led study. The blitzkrieg advance of two closely related species of mussels—the zebra and quagga—is stripping the lakes of their life-supporting algae, resulting in a remarkable ecological transformation and threatening the multibillion-dollar U.S. commercial and recreational Great Lakes fisheries. Previous studies have linked the mussels to far-reaching changes in Lake Michigan's southern basin. Now a paper by two University of Michigan ecologists and a colleague shows that the same dramatic changes are occurring in northern Lake Michigan and throughout Lake Huron, as well. "These are astounding changes, a tremendous shifting of the very base of the food web in those lakes into a state that has not been seen in the recorded history of the lakes," said Mary Anne Evans, lead author of a paper scheduled for publication in the April 15 edition of the journal Environmental Science & Technology. "We're talking about massive, ecosystem-wide changes." Evans is a research fellow at the U-M School of Natural Resources and Environment. The other authors are Donald Scavia, director of U-M's Graham Environmental Sustainability Institute, and Gary Fahnenstiel, senior ecologist at the National Oceanic and Atmospheric Administration's Great Lakes Environmental Research Laboratory.