Effects of a Sweeping Low Frequency Pulsed DC Electrical Field on Bighead (Hypophthalmichthys nobilis) and Silver (Hypophthalmichthys molitrix) Carp Behavior in a Zero Flow Environment

The ability to control movement and passage of fish has utility from preventing movement through locks and dams to labor reduction and efficacy of fish collection in aquaculture. Traditional graduated field fish barriers immobilize fish as they swim upstream through the field and subsequently returned downstream from the barrier via flow. In low to no-flow environments such as a lock chamber, however, there exists no flow capable of returning fish downstream of the barrier. The effectiveness of a sweeping field requires fish to move away from a targeted area with little detriment to swimming. The goal of this research was to evaluate the efficacy of electric field settings to direct carp movement. This presentation will discuss and compare the behavioral responses of two small size classes of bighead (mean TL 22 cm) and silver (mean TL 16 cm) carp to a low voltage, low frequency pulsed DC sweeping field. Fish were placed in a 24 m long X 2.5 m wide X 1 m water height raceway and exposed to a moving electric field until all fish were direct into predefined areas at either end of the raceway. Fish movement was recorded by video surveillance and PIT tag array equipment.