CONTENTS 



Page 



Introduction 1 



Retention of adult salmon 2 



Holding pond design 2 



Prevention of self-inflicted injury 2 



Factors influencing tissue repair and disease inhibition 2 



Effect of current velocity on disease inhibition 2 



Results of experimental holding 4 



Carrying capacity 4 



Ponds in series 6 



Adaptations 6 



Holding pond traps 8 



Holding pond trap design 8 



The upstream trapping system 11 



The downstream trapping system 11 



Operation of the trapping facilities 11 



Routine procedures 11 



Abnormal situations 12 



Construction 12 



Summary 13 



Literature cited 13 



ABSTRACT 



Holding ponds have been developed for the retention of the Pacific salmon 

 ( Oncorhynchus ) during the interval between the upstream and spawning migrations . 

 This pond type, operated either singly or in series, is a long, narrow channel with 

 a diffused water intake and sloping banks to minimize self-inflicted injuries during 

 the holding period. An average current velocity of 0.2 fps is maintained through 

 the pond when water temperatures exceed 60° F. to reduce the incidence of disease. 

 Both upstream and downstream trapping facilities are installed in the holding ponds 

 to capture the sexually mature adults for artificial propagation. The characteristic 

 reactions of the confined salmon are described. Design drawings of the holding 

 ponds and trapping facilities are included. 



