The nine-foot channel affected raccoon populations in several 

 ways. An increase in water area initially provided more feeding 

 habitat for raccoons, but in recent years sedimentation reduced the 

 quality and quantity of aquatic food. Slower current velocity and 

 deeper water as a result of the nine-foot channel coupled with in- 

 creased agricultural runoff have silted in valuable marsh areas which 

 provide feeding areas for raccoons. Extensive bottomland clearing 

 made in conjunction with the implementation of the nine-foot channel 

 along the Illinois and Mississippi Rivers in Calhoun County destroyed 

 habitat, forcing raccoons into the uplands (Brown and Yeager, 1943: 

 463). 



Population data for raccoons found exclusively in the bottomland 

 forest of the Illinois and Mississippi are not available: therefore, a 

 quantitative interpretation of raccoon populations affected by the nine- 

 foot channel is not possible. 



Mink 



The mink, an animal that is highly adaptable and at home on land 

 or in the water, was reported by Yeager (1949: 60) as being affected 

 by the Calhoun Point inundation on Pool 26 of the Illinois River less 

 than any other fur species. 



The abundance of mink is a function of shoreline: the more shore- 

 line, the greater the potential population of this species. The 

 amount of shoreline decreased in the lower third of Pools 24-26 with 

 the submergence of islands; shoreline was enhanced in the middle third 

 of the pools, and remained about the same in the upper third. 



Therefore, potential mink habitat both decreased and increased as 

 a result of the 9-foot channel project. Overall the losses and 

 benefits probably balanced. Although no quantitative data on mink 

 inhabiting the bottoms are available, narrative reports for the Cal- 

 houn and Batchtown units of the Mark Twain Refuge system indicate that 

 mink populations fluctuated as a result of pool operations 

 during the 1940 's and early 1950' s. The populations increased steadily 

 until the mid- 1 960' s and then declined. This decline is presumably a 

 result of two factors: (1) a loss of marsh habitat attributed to sedi- 

 mentation, and (2) trapping pressure (Tables 50-53) . 



182 



