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ABBREVIATIONS USED IN THIS REPORT x 



PREFACE 1 



The River 



The Conflict 1 



The Study 3 



Acknowledgments 4 



INTRODUCTION 5 



Purpose 5 



Scope 5 



Study Area 5 



METHODS 17 



Samplinq Methods and Materials 17 



Species Diversity Calculations 19 



Mean Diversity (d) 20 



Equitability (E m ) 21 



Redundancy (R) 22 



Evenness (J') 22 



Species Richness (SR) 23 



AN INTRODUCTION TO FAUNAL ZONATION 25 



EXISTING SITUATION 31 



Macroinvertebrate Distribution 31 



Yellowstone River 31 



Tongue River 42 



Insect Emeraence 42 



Mayflies 42 



Stoneflies 42 



Caddisflies 50 



Bottom Fauna Population 52 



Species Diversity 59 



Feeding Mechanisms 67 



Current and Depth Requirements for Invertebrates 67 



Data Collected 67 



Environmental Requirements 75 



IMPACTS OF WATER WITHDRAWALS 95 



Chemical 95 



Silt 95 



Temperature "6 



Current and Bottom Habitat , • • i 96 



SUMMARY 103 



LITERATURE CITED 105 



