14 Lake Maxiy^knckee, Physical and Biological Survey 



Maine, New Hampshire, Vermont, and perhaps others. As many 

 of these investigations were made in response to resolutions of 

 Congress calHng upon the Commission to determine the desirabil- 

 ity of establishing fish-cultural stations in certain States, it can 

 be seen that a wide area had to be covered and that the investi- 

 gations were necessarily hurried and incomplete except for the 

 specific purpose in view. Occasionally, however, it was possible 

 to confine the season's investigations for a longer period to a lim- 

 ited area, and more thorough work resulted ; as, for example, upon 

 the Redfish Lakes in Idaho in 1895 and 1896, the Connecticut 

 Lakes in 1904, and the Rangeley Lakes and Sebago Lake in Maine 

 in 1905-1913. 



The need of exact knowledge of the physical and biological 

 conditions obtaining in the various types of lakes and streams 

 became increasingly evident. In the direct interest of fish cul- 

 ture, there was great need of more complete knowledge of the 

 habits not only of our most common food fishes, but also of the 

 animals and plants associated with them, and of the physical and 

 biological conditions under which they thrive. 



Not until 1899, however, was any such work undertaken under 

 really favorable conditions. It was in that year decided to select 

 a small lake and make such a study of it as might serve as a 

 model for the investigation of all similar lakes. 



There are, in the upper Mississippi Valley, particularly in Ohio, 

 Indiana, Illinois, Michigan, Wisconsin, Minnesota and Iowa, many 

 thousand lakes of glacial origin. With scarcely an exception, these 

 lakes teem with food and game fishes of the finest quality, besides 

 many other species of greater or less importance. Many of these 

 lakes are inhabited also by a large number of species of turtles, 

 batrachians, mollusks and crustaceans, some of which are already 

 used for food or otherwise utilized by man. They are the home 

 also of many other species of aquatic animals and many species 

 of aquatic plants which are known to serve an important purpose 

 in the economy of the lakes in their relation to food fishes, and of 

 still many other species whose status we do not yet know. 



The value of exact knowledge concerning this type of lake and 

 the inhabitants thereof is appreciated by all biologists and fish- 

 culturists and can scarcely be overestimated. 



In making selection of a particular lake for study along these 

 lines it was important that the lake chosen should meet certain 

 essential conditions. It must not be too large; it must be suffi- 

 ciently compact to enable any or all parts to be reached readily 

 from a central station ; there should be no inlets or connecting 



