CONTENTS 



Page 



Introduction 1 



Field measurement of size composition 2 



Collecting samples 2 



Sorting and measuring samples 3 



Permeability and its relation to composition 4 



Method of measuring permeability 5 



Results of permeability tests 5 



Size composition and spawning success 6 



Silt removal by spawners 9 



Volumes removed 9 



Organic content 9 



Spawning bed siltation 9 



Silt pollution from logging 9 



Silt content of spawning beds 12 



Effect of silt on permeability 12 



Silt removal by flooding 12 



Summary 14 



Literature cited 14 



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