All week on Absolute Michigan & Michigan in Pictures we’re looking at invasive species and their impact on Michigan. Zebra mussels and the more recent invader quagga mussels belong to the dreissenid mussel family and many contend that they have had a more serious impact on the Great Lakes than any other invader. Via an excellent feature in the Grand Rapids Press, Zebra mussels’ damage make them the worst of all Great Lakes exotic species, scientists say:
“In terms of the whole food web, I don’t think there’s any question that zebra and quagga mussels have had the largest impact on the biological communities of the Great Lakes,” said Tom Nalepa, a research biologist at the federal government’s Great Lakes Environmental Research Laboratory in Ann Arbor.
Sea lamprey only affected fish at the top of the food chain. Zebra and quagga mussels have caused profound changes at all levels of the food chain in every Great Lake except Superior, Nalepa said.
These small but potent invaders have clogged water intakes at power plants and water treatment facilities (adding $2 billion to annual costs), decimated algae and other plankton including nearly 100% of diporeia in some areas, severely impacted prey fish fish populations and those of the predatory fish like whitefish, trout and salmon, created conditions for toxic algae blooms that have fouled beaches, killed fish and more than 70,000 fish-eating birds, including bald eagles and common loons. In short, they have come into the Great Lakes and hundreds of our lakes & rivers and radically changed them.
Now quagga mussels are supplanting zebra mussels and – like Wicked Witches – the second one is even worse than the first. The Christian Science Monitor ran a feature the other day with the dire headline Lake Michigan’s ecosystem facing collapse that says that the mussels are consuming phytoplankton at a rate that’s five to seven times greater than it is being produced.
While there’s no way to put the zebra/quagga genie back in the bottle, we can slow their advance by following some simple steps when we move boats from lake to lake. In closing, here’s an excellent video feature, Quagga & Zebra Mussels – What are they and where did they come from?, that was produced to make people in the west aware of the threat: