The Great Lakes: A Primer

The Chicago River is 156 miles long, counting tributaries, and is two to 21 feet in depth. Chicago is a perfect location for any city. Chicago is at such a great location because of the huge mass of freshwater that is located nearby. The waters of Lake Michigan are a great natural resource of Chicago.

The Chicago River runs into the Lake Michigan. The tributaries of Chicago River are very important to our city also. The tributaries of the Chicago River help to bring water through the city of Chicago. The tributaries, however, caused problems at first. In the mid to late 1800's the water of Lake Michigan was very filthy and polluted. As more people came to Chicago and the more population Chicago had, the filthier and more polluted the lake became.

In the 1900's the Sanitarian Ship had used the tributaries of the Chicago River and using a locking chamber system, had reversed the flow of the river. Reversing the flow of the river meant the sewer water would be further drained and the tributaries and water supply of Lake Michigan would be kept pure.

The tributaries of the Chicago River had been drenched and straightened. It also was used for agricultural drainage. Now the tributaries of the Chicago River serve the purpose of shipping out goods.

The abundance of freshwater of our great lakes is an amazing resource. If we can conserve our water and ration the supply, the freshwater can last for many more years to come. Many protested and argued when in 1998 millions of gallons of freshwater was being shipped overseas. Many problems could arise from a water level drop in Lake Michigan. The wetlands could dry out and the water could heat up faster and cause harmful bacteria to grow. Also the ships wouldn't be able to travel on shallow water. Although no actual formal laws are set in place to maintain the water supply, there has been no further abuse of the supply since 1998 and water is inspected to observe the purity of it.

There is also conservation on the sand dunes of Lake Michigan. There can't be more than 33% of buildings built on the dunes. Preserving the dunes can maintain the ecology of Lake Michigan.

There are many native plants and animals to lake Michigan, but there are also invasive species. Invasive species are animals that come to an environment because of transportation such as the underside of boats or other methods.

The sea lamprey was first spotted in Lake Michigan in 1936. This eel-like predator with razor-like teeth rid off of many lake trout, lake sturgeon, Lake Whitefish, and burbot. These fish had no natural defenses against the sea lamprey. The sea lamprey had killed off most of the native species of fish to Lake Michigan as well as a significant amount of exotic fish. By the mid 1950s, lamprey had eliminated the native population of lake trout in Lake Michigan, and significantly reduced populations of other species. Like the sea lamprey, the alewife also entered the upper Great Lakes. When the lake trout population decreased in the 1950s, there were no predators to control alewife and their population grew rapidly.