A Freshwater Fish Electro-Motivator 



(FFEM)— Its Characteristics and Operation 



by 



JAMES E. ELLIS, Fishery Biologist' 



National Marine Fisheries Service 



Fish Farming Development Center 



P.O. Box 711 



Rohwer, AR 71666 



and 



CHARLES C. HOOPES, Ph.D.^ 



Research Engineer 

 University of Michigan 

 Ann Arbor, MI 48104 



ABSTRACT 



A prototype Freshwater Fish Electro-Motivator (FFEM) system was developed as a 

 research tool to test the application of electricity for use with active and passive fishing 

 gear for increasing the gear's catching efficiency. The system's basic characteristics and 

 operating modes are explained. The prototype system is extremely sophisticated, and its 

 versatility permits single or multiple time-sequenced electrode loading and various pulse 

 patterns, and allows duty cycles over a wide dynamic electrode load range. A summary of 

 the field testing is discussed. 



INTRODUCTION 



In 1966, investigations into the application of 

 electricity in conjunction with fishing gear were 

 undertaken by the National Marine Fisheries 

 Service at Ann Arbor, Mich. The specific aim of 

 these investigations was to develop an electrical 

 appciratus for researching the application of 

 electricity for commercial fishing of all fresh- 

 water fish stocks in the Great Lakes. In essence, 

 this gear was to be designed for any freshwater 

 species found in the contiguous 48 States. 



1 



Wildlife, Fish Farming Development Center, Rohwer, 

 AR 71666. 

 2 

 Present address: Cyphernetics Corporation Product 

 Manager, Ann Arbor, MI 48104. 



Work by other investigators had demonstrated 

 that bottom trawls lost up to 60% of their catch 

 due to fish escapement back through the trawl's 

 mouth area (Kreutzer, 1964). McRae and 

 French (1965) and Shentaykov (1965) demon- 

 strated that the overall catch rate of an 

 electrified bottom trawl was increased by as 

 much as 2.0 to 2.5 times. EUis (1972) showed 

 that electricity increased an electrical trawl's 

 catch rate up to 1.86 times that of a standard 

 control trawl. Seidel (1969) showed that a 

 commercially feasible shrimp fishery in daylight 

 hours was practical if electricity was used in 

 conjunction with a trawl. 



Our review of prior work indicated that 

 available fish shockers were not fully utilizing 

 electrical currents for obtaining maximum 



