A Model for Estimating Electrofisher Peak Power and Effective Electrofishing Range Across Water Conductivities

The results of laboratory studies under controlled conditions were used to develop a generalized model for predicting the maximum output of peak power for electrofishers when using either continuous or pulsed direct currents.  Model inputs include electrofisher ratings for output power (average watts), peak voltage (volts) and peak current (amperes) plus electrode resistance (ohms) at a water conductivity of 100 µS/cm, and pulsed direct current duty cycle.  The results are depicted on a graph which includes resistance on the x-axis and peak power on the y-axis plus diagonal lines for voltage and current.  Electrode resistance is a function of water conductivity, so the predicted maximum output of peak power for a given resistance can be easily converted to that for water conductivity using the model’s built-in calculator.  One model version, Backpack Power, is for backpack electrofishers, and another version, Boat Power, is for electrofishing boats.  Both include a power goal line which is minimal at a resistance corresponding to a water conductivity and effective fish conductivity value of 115 µS/cm, i.e. for the conductivity match between water and fish.  The power goal line for Boat Power is set at 3000 watts at matched conditions based on a published power goal table, and the power goal line for Backpack Power is based upon empirical data.  Also available in each version is a user-defined power goal line so that individuals can use their own electrofishing results at an ambient water conductivity to create a customized power goal for their unit when operated at other water conductivities.  The graph can be used to estimate the effective conductivity range of suitable operation for a given electrofisher as well as to estimate power capacity beyond that needed for standardizing by power.