Michigan Inland Lakes Partnership

A lake’s ability to support plant and animal life defines its level of productivity, or trophic state. Lakes are commonly classified based on their productivity. Low productive oligotrophic lakes are generally deep and clear with little aquatic plant growth. These lakes maintain sufficient dissolved oxygen in the cool, deep-bottom water during late summer to support cold water fish, such as trout and whitefish. By contrast, high productive eutrophic lakes are generally shallow, turbid, and support abundant aquatic plant growth. In deep eutrophic lakes, the cool bottom waters usually contain little or no dissolved oxygen. Therefore, these lakes can only support warm water fish, such as bass and pike. Lakes that fall between these two classifications are called mesotrophic lakes. Lakes that exhibit extremely high productivity, such as nuisance algae and weed growth are called hypereutrophic lakes.

The above information was taken directly from the 2008 Annual Summary Report of Michigan’s Cooperative Lakes Monitoring Program, published by the Michigan Department of Environmental Quality (Report No. MI/DEQ/WB-09/005).