Ecosystem Functions & Changes

In the year 2000 a group of Great Lake scientists discovered what is now known as the “doughnut in the desert” in Southern Lake Michigan’s winter waters, the “doughnut in the desert” is a ring shaped bloom of tiny aquatic plants. The bloom of the “doughnut” takes place in the southern 100 miles of Lake Michigan in late winter (March & April). Scientists believe the “doughnut in the desert” is produced by winter storms and winds that build up a current that is moving counter-clockwise in the lake and from these current nutrients from the bottom of the lake are being brought up. The doughnut helps shed some light on how other species in the lake were surviving in the winter, a time thought to be short on food. The joyous discovery of the doughnut would be short lived. Almost as soon as the scientists discovered the doughnut it was disappearing.

In the late 1990s it is believed that the quagga mussel’s arrival was in ship ballast tanks,

and throughout the 2000s the quagga mussels’ dieted on the doughnut, causing the doughnut to slowly disappear, disrupting Lake Michigan’s food chain. Scientists believe by the vanishing of the doughnut there could be a disturbance in the food chain in Lake Michigan. The bloom of the doughnut basically sends out a dose of food to the microscopic animals in Lake Michigan that wait out the winter in open waters, if these tiny animals that survive off the doughnuts food starve, so could the fish that depend on these smaller species for a large meal in the springtime, and this action will repeat itself throughout the food chain in Lake Michigan. The quagga mussels’ are not only disrupting the food chain in Lake Michigan but also quality of life within the lake. A single quagga mussel can filter a quart of water a day, the quagga mussels’ are also known as filter feeders, their constant sucking in of the lake water and clearing it of all foods that other species in the lake depend on for survival. There is approximately