Assessment of Outputs from Smith-Root Model-5.0 GPP and Model-7.5 GPP Electrofishers

We evaluated the outputs from eight Smith-Root electrofishers (two factory-rigged model-5.0 GPP boats, four biologist-rigged model-5.0 GPP boats, and two biologist-rigged model- 7.5 GPP boats), using an oscilloscope to determine the actual waveforms (voltage as a function of time), current, and power produced for various settings. Differences were found in average power outputs among the six model-5.0 GPP electrofishing boats. In terms of average power output, biologist-rigged electrofishing boats using generators and control boxes purchased from Smith-Root were as or more effective than those rigged by Smith-Root. However, factory-rigged boats generally contained additional safety features that should be considered when purchasing electrofishing equipment. Outputs were similar between the two model-7.5 GPP boats. We were unable, with information obtained solely from the control boxes, to calculate power output produced by the Smith-Root electrofishers. Thus, additional meters (e.g., a voltage meter capable of measuring true root mean square) would be needed to determine power output in the field. An increase in resistance (simulating a decrease in water conductivity) resulted in a decrease in average power and current and a slight increase in voltage