A Measure of the Efficiency of Alternating and Direct Current Fish Shockers
- 1 January 1952
- journal article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 81 (1) , 63-68
- https://doi.org/10.1577/1548-8659(1951)81[63:amoteo]2.0.co;2
Abstract
Two shockers, one powered with a 500‐watt, 110‐volt, 60‐cycle alternating current generator, the other with a 2,500‐watt, 230‐volt, direct current unit, were compared in two blocked‐off sections of Spring Brook, Kalamazoo County, Michigan. An indication of the efficiency of the D.C. unit in recovering marked fish from extremely turbid water was obtained in an unblocked section of Wilder Creek, Calhoun County, Michigan, where the use of the A. C. machine was impracticable. In one Spring Brook section, the fish were shocked, marked, and recovered first with the A. C. unit and then with the D. C. The procedure on the other section was similar except that D. C. was used first. In the swifter section, recoveries of individual species varied from 0.0 to 100.0 percent with both shockers. Of the total marked fish present, 44.8 percent were recovered with D. C., 28.8 percent with A. C. In the other section, the recoveries by species varied from 9.1 to 66.7 percent. Here, 41.2 percent of all marked fish present were taken with D. C., 35.1 percent with A. C. Combined results on both sections indicated a rate of recovery of 42.9 percent with D. C. and 33.3 percent with A. C. Although a single recovery of 75.0 percent was noted for one species on Wilder Creek, the total recovery of all species was only 16.4 percent. Of the two shockers described, the D. C. unit seemed to give much better results, particularly in swift and turbid waters.This publication has 0 references indexed in Scilit: