And thus, with little organic food, we find only small populations of bacteria. Moreover, with only small numbers of plankton and bacteria, we have very little consumption of oxygen, from the deeper waters. One typical measure of an oligotrophic lake is that it has lots of oxygen from surface to bottom. There are other chemical characteristics, but these are the ones most often mentioned. The bottom of oligotrophic lakes are most often sandy and rocky and usually their watersheds are the same, resulting in few nutrients entering the lake.
Oligotrophic lakes have nice clean water, no weed problems and poor fishing.
They are often deep with cold water. We find most of our oligotrophic lakes in Michigan in the upper peninsula and in the upper third of our lower peninsula. Eutrophic lakes are the general contrast to the oligotrophic lakes and lie at the other end of the continuum. They are rich in plant nutrients and thus their productivity is high. These lakes also produce high numbers of zooplankton and minnows and other small fish that feed on the zooplankton.