THE ESTATE 

 DWINDLES 



Farm Drainase 



111 tlie HHi yeiirs before 1955, our wetlands were 

 reduced by 45 percent. Losses to agriculture ha\e 

 been extensive, and more than a million acres of 

 prairie potholes have been drained since 1943. 

 Larger thainage systems may include several 

 farms. Manj' drained lands produce good crops — 

 the cost of preser\iiig wetlands is high. 



Dredsing — Siltation — Pollution 



Coastal wetlands are seriously damaged when 

 channels are cut for mosquito control or for navi- 

 gation. The intricate balance between wet and 

 dry areas, fiesh and salt waters — the key to pro- 

 ductivity — is disrupted. 



.-> :, 





I 



Loui.MdiKi IVi(rf Lite and FishrriCH Commission 



Stream Channelization 



AVlien stream ciiaiinels are straightened, flood- 

 waters no longer overflow to attract ducks to the 

 l)()ttom lands. Tlie dredged spoil from channel 

 maintenance lills many marshes and tiie silt de- 

 stroys tlie productivity of downstream estuaries. 

 Pollution reduces and frequently destroys the 

 \alue of wetlands for fish and wildlife near urban 

 areas. 



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