Laying the foundations for selective-fish guidance using electricity: multi-species response to pulsed direct...

Area of Science:

• Aquatic Ecology
• Fisheries Management
• Electrophysiology

Background:

• Invasive species pose significant ecological and economic threats.
• Effective management strategies are needed to control invasive fish populations.
• Electric fields show promise for guiding fish, but species-specific sensitivities must be understood.

Purpose of the Study:

• To quantify the electrosensitivity of invasive grass carp and common carp.
• To compare the electrosensitivity of these carp species with European eel.
• To assess the potential of pulsed direct current (PDC) electric fields for selective fish guidance.

Main Methods:

• Experimental quantification of electrosensitivity across four PDC electric waveforms.
• Identification of electric field strengths eliciting physiological responses (twitch, loss of orientation, tetany).
• Comparison of responses between grass carp, common carp, and European eel.

Main Results:

• Grass carp exhibited waveform-specific sensitivity, with tetany at lower field strengths in the single pulse-2 Hz treatment.
• Both carp species were less sensitive to PDC than European eel.
• Grass carp showed loss of orientation at lower field strengths than common carp in the single pulse-3 Hz waveform.

Conclusions:

• Electrosensitivity varies significantly among fish species, influenced by factors like body length.
• Pulsed direct current electric fields demonstrate potential for selective guidance of fish.
• This technology could aid in managing invasive species in sympatry with native fish.