ABSTRACT 



An account is given of experiments conducted in 1951 

 and 1952 with electromechanical and electrical barriers for the 

 blocking and/or capture of sea lamprey runs in tributary streams 

 of northern Lake Huron and northern Lake Michigan. Details are 

 presented on structural characteristics, experimental manipula- 

 tions, and effects on sea lampreys and other fish. All installa- 

 tions were operated from 110-volt alternating current power. On 

 the basis of the experiments detailed, recommendations are offered 

 on devices suitable for the control of sea lampreys under various 

 stream conditions. The general structure and plan, and electrical 

 characteristics of the devices must be adjusted to such factors as 

 depth of water and extent of its fluctuation, rate of stream flow, 

 physical nature and conductivity of bottom materials, conductivity 

 of water, and need for the protection of fish that migrate simul- 

 taneously with the sea lamprey. 



