Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 7201
Title: Relationship of fish size and water velocity to the fish guiding effectiveness of a single-row electrode array
Author: H William Newman, Alan B. Groves
Publication Year: 1960
Journal: Proceedings of the Montana Academy of Sciences
Volume: 19
Pages: 84-90

Providing safe passage for fingerlings around obstacles is a major undertaking of fishery, reclamation, power, and flood control agencies in the Pacific Coast region.  Investigations into this problem have included attempts to utilize screens, louvers, sound, pumps and electricity.  Of these means, perhaps the one creating the most interest has been the use of electricity for guiding fingerlings. 

The U.S. Fish and Wildlife Service began a systematic program in 1951 to develop electrical fish screens.  This program, begun as laboratory studies at the Seattle Biological Laboratory (formerly known as Pacific Salmon Investigations), is now undergoing large-scale field trials at Lake Tapps in Pierce County, Washington.  Laboratory tests have outlined the factors which contribute to mortality, conditions which are best for electrical control of swimming, types of electrodes and array orientation, duration and frequency of pulsed DC, and orientation of the electrical field with respect to water flow. 

The purpose of this report is to present data of an experiment designed to test the relationship of both fish size and water velocity to the fish-guiding effectiveness of a single-row electrode array.  Since we realized early that fish of different sizes are affected to a different degree by an electrical field, we had planned to experiment with fish size as a variable.  The results of field trials in the spring of 1955 indicated that certain unknown factors at times reduced guiding effectiveness.  Laboratory explorations into the problem indicated that water velocity might be a significant factor.  Therefore, water velocity and fish size were examined simultaneously in August of 1955.