Distribution of the Larger Fishes in Minnesota Lakes, 1948 to 1967

This report maps the distribution of larger fishes in Minnesota, as indicated by test net catchers from routine lake surveys conducted between 1948 and 1967. It does not include fishes that occur in streams and rivers except for river lakes such as Lake Pepin. The net catch data was derived from over 1,700 surveys of 1,580 lakes: a sample of sufficient size to permit working out the distribution of many of the larger fish species. Although lakes in the state are not randomly distributed, a sufficient number of lakes have been surveyed in each climatic region to gain an overall picture of their distribution. Many species of fish occur only in certain areas of the state. The fish distribution maps in this report were compiled to aid administrators, managers, and researchers. The maps should help form the basics for ongoing distribution studies covering all Minnesota fishes. This discussion is restricted to lakes, because some species occur in lakes in one part the state and are primarily restricted to streams in another part of the state. A good example is smallmouth bass. Smallmouth bass are frequently found in lakes in the northern part of the state, especially the northeastern counties, and occur commonly in streams and rivers in the southern part of the state. Some comments on the obvious reasons for the various distributions will be made, but an extensive literature review will not be attempted because Underhill (1955) has reviewed the literature and discussed the distribution of small stream fishes which have not stocked extensively throughout the state. Many of the fishes have been stocked throughout the state so their presence or absence is likely to be regulated by their tolerance of existing environmental conditions, or be regulated by the factors discussed by Underhill.