Rarely does a new model electrofisher hit the market, so it is fortunate to be able to evaluate it in some respects. The first backpack electrofisher we bought at a federal fish hatchery for capturing possible mussel host fish was an Appalachian Aquatics AA-24. It had multiple voltage ranges, but the waveform was fixed at 120 Hz pulsed direct current with a duty cycle that varied slightly with load from about 73 to 80 percent. Despite the fixed frequency and duty cycle, it captured fish well. It was sturdily made, and I understand those units are still operating after 15 years of service. One day, we had the opportunity to use the AA-24 at the same stream as an ETS ABP-3 and a Smith-Root LR-24. As I recall, the ambient water conductivity was about 40 μS/cm, so we set each unit to 400 volts and began shocking. All three units successfully captured small stream fish, and we saw in this short comparison no real differences in fish catch among the three units.
This information is from an electrofishing workshop held at Table Rock Lake, Missouri in June 2012 for the Missouri Department of Conservation. The aluminum electrofishing boat was 16 ft (4.9 m) long, and its hull was used as the cathode. There were two booms, each with Wisconsin rings of 83 cm diameter, and each ring had 11 metal droppers 22 cm long x 1.3 cm diameter. Distance from the center of the booms to the nearest boat hull waterline was approximately 250 cm.
Opportunity knocks! The National Conservation Training Center (U.S. Fish & Wildlife Service) is offering an electrofishing course in Carterville, Illinois during October 23 – 27, 2017. Please see course description, course flier, and registration process below.
Often electrofishing sampling is unsatisfactory (low effectiveness, high variance) due to reasons that include equipment limitations, insufficient understanding of equipment function, inadequate electrode design, and a lack of guidance regarding proper settings given prevailing water conditions and target species. This class addresses these factors and builds skills in participants that will enable them to tackle sampling issues and increase the efficiency and standardization of electrofishing.
In addition, participants learn how to evaluate gear performance and select suitable equipment, trouble-shoot equipment, assess likelihood of fish injury and use approaches to minimize the potential for stress and injury, and provide a safer operating environment for their crews.
This course covers all types of electrofishing gear types including boats, rafts, tow-barges, shore-based, backpack, electric seine, and pre-positioned.
Participants are encouraged to bring their equipment for evaluation which includes analysis of outputs, calibration check, electrode design, and a safety workup. Gear also is used for standardization exercises.
Registration process for non-Department of Interior Biologists: