Effective Boat Electrofishing Technique in Warmwater Lakes
Although power and other forms of standardization are considered when using boat electrofishing, some of the most fundamental aspects of boat electrofishing standardization remain little studied. AFS standard methods call for continuous electrical output, but many biologists have adopted an intermittent output where power is administered at certain intervals, usually dependent on the biologist’s judgement. This method has been adopted from the idea and observations that a continuous power output can “herd” fish, where fish can feel the electricity coming and swim away. With an intermittent output, biologist theorize they can let off the power to get in the range of these fish, allowing them to get shocked and sampled. To test effect of these fundamental concepts on boat electrofishing efficiency, fisheries biologists across the nation were surveyed to investigate the most common electrofishing driving and shocking techniques (continuous, intermittent, or other). From this we chose parallel to shore continuous shocking, parallel to shore intermittent shocking, and arc-driving intermittent shocking to test in Arizona reservoirs. We compared CPUE, mean size and species composition between the three types of electrofishing sampling methods. Although the three methods were similar, arc-intermittent resulted in a slightly higher catch per unit effort for some species than the other techniques. Field work on this project was concluded, a thesis was written presenting results, and a publication on this work is now under review.