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Spheres, Rings, and Rods as Electrodes in Electrofishing: Their Effects on System Resistance and Electrical Fields
Author(s) -
Reynolds James B.
Publication year - 2016
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1080/00028487.2015.1114519
Subject(s) - rod , electrode , materials science , electrofishing , spheres , composite material , voltage , electrical resistance and conductance , electrical engineering , physics , fish <actinopterygii> , medicine , alternative medicine , pathology , quantum mechanics , astronomy , fishery , biology , engineering
Three shapes of electrodes are used for most electrofishing: spheres, rings, and rods. The predictive value of theoretical equations and relative effects of electrode size, shape, and stock diameter (material thickness) on electrical characteristics have not been evaluated by designed experiment. I performed an experiment in a hatchery raceway, using minimum and maximum electrode size‐shape categories common in electrofishing: 15‐cm‐ and 30‐cm‐diameter spheres and rings and 48‐cm‐ and 96‐cm‐long rods (lengths equivalent to ring circumferences). Each size of ring and rod was fabricated in four stock diameters: 3, 6, 10, and 13 mm. Eighteen identical pairs of electrodes (two spheres, eight rings, eight rods) were energized with 120‐V, 60‐Hz sine‐wave AC. Observed values of system resistance (representing potential power demand), voltage gradient at 0–1 cm from an electrode surface (high‐hazard zone for fish), and distance to 0.1 V/cm (effective field size) were measured. Both size–shape and stock diameter had highly significant ( P ≤ 0.01) effects on system resistance, high‐hazard zone, and effective field size. Size–shape effect was about nine times more important than stock diameter in its influence on system resistance; about six times more for effective field size; and about twice more for the high‐hazard zone. Boundary conditions imposed by the raceway limited the usefulness of theoretical equations; such boundaries would also exist in natural waters. Empirical measurements of circuits and fields are more accurate and realistic, than theoretical values, for application of electrode design. Lacking one's own empirical data, the data from this study may be used to test virtual electrofishing systems for electrode design. Scenarios are offered as examples for practical application of the results of this study. Received November 25, 2014; accepted October 13, 2015