Midwest Fish & Wildlife Conference 2019

AUTHORS: Scott F Collins, Anthony Porreca, Michael Nannini, Joseph Parkos III, David Wahl – INHS

ABSTRACT: A modular electrical barrier (MEB) was developed as a tool to deter or disrupt the movement of fishes for the purposes of an adaptive approach to pest management.  The design required a non-physical barrier that would not impede boat traffic or floating debris, sufficient power to generate an electrical field at a diverse set of locations, modularity such that the MEB can be transported to logistically feasible locations, and be safely operable by fisheries professionals. The MEB system consists of generators which provide power to one or multiple 5-kW pulsers which modulate the electrical output to the electrodes (anode and cathode steel cables).  Individual pulsers can be linked to fit location dimensions (depth, width, conductivity). To test the effectiveness of the MEB, we conducted an experiment consisting of two trials in separate 0.4-ha ponds.  For each trial, we constructed a large RFID antenna (1 × 30 m) and PIT-tagged (23 × 3.85 mm HDX tags) individual fish from 8 species (4 invasive, 3 native) in order to track fish activity (total detections; average detections) in response to operation of the MEB.  When the MEB was off, ambient fish activity ranged from 500-1600 detections per day.  While the MEB was on, the number of fish detections dropped to only 7 total (6 or 0.05% of trial 1; 1 or 0.01% of trial 2), and most detections were associated with fish mortality.  After the MEB was turned off, fish detections increased after a few hours, and fish activity returned to peak numbers after 4.5 days.  Findings from this experiment indicate that the MEB can greatly deter fish movements; however, like all non-physical barriers, it may not be 100% effective at stopping fish.