Chapter 15: Natural Lakes
Michael J. Hansen, Nigel P. Lester, and Charles C. Krueger
Natural lakes are important resources throughout North America and contribute substantial economic benefits to people through fishing, boating, swimming, and other recreational uses. Recreational, commercial, and subsistence fisheries are among the most important, though rarely exclusive, social and economic values of natural lakes. Therefore, fisheries managers of natural lakes must balance demands for fishing with demands for boating, swimming, or other uses, which requires managers to be skilled in fishery science, resource economics, and public policy.
This chapter focuses on the unique attributes of natural lakes that challenge managers within the larger environment of fisheries management. The chapter begins with an overview of natural lakes in North America. Next, types of fisheries found in natural lakes are described (section 15.2), which serves as a background for methods of predicting fishery potential in natural lakes (section 15.3) and common management goals for different types of fisheries in natural lakes (section 15.4). Next, methods for evaluating fishery potential in natural lakes (section 15.5) and strategies for managing fisheries in natural lakes are presented (section 15.6).
Natural lakes are formed by the interplay between climate and geologic forces (Wetzel 2001). First, geologic forces must form a basin in which water can be held, and second, precipitation must be adequate to supply enough water to offset evaporative, seepage, and outlet losses, thereby sustaining water in the lake basin throughout the year. As a consequence of geology and the interplay between availability of water and lake basins, most natural lakes are in the northern and eastern parts of North America, where annual precipitation is adequate and glaciers left numerous basins for storage of surface waters. In contrast, lakes are less common in western and southern North America, either because few lake basins are present or precipitation is insufficient to overcome evaporation or seepage losses.