It’s happening now, the CS Monitor writes. The entire Lake Michigan ecosystem is collapsing:
The quagga [mussel] is found in all of the Great Lakes; the invasive species was introduced by ocean-going vessels dumping ballast water. Their favorite food is phytoplankton. Hank Vanderploeg, a colleague of Kerfoot’s, calculated that they consume phytoplankton at a rate that’s five to seven times greater than the plants are being produced.
All the energy in the phytoplankton, which once fed fish, is now being sucked down to the bottom of the lake by quaggas. Their waste can stimulate the growth of Cladophora algae, which die, decompose and remove all the oxygen from the surrounding water.
Under such conditions, populations of zooplankton will decline, as will the alewives, chubs, Atlantic salmon, muskies, smelt, walleyes, perch and the rest of the hundred or so species of fish that inhabit Lake Michigan.
Probably ironic that this extinction event is being caused by a mussel that’s named for another extinct animal.