Lab and Field Tests of the Neptun Low-Voltage DC Fish-Guidance System to Block Sea Lamprey Migration and Guide Sea Lamprey into Traps

The sea lamprey is a Great Lakes invader that contributed to the collapse of native fish communities during the mid-1900s.  Since the 1960s, sea lampreys in the Great Lakes have been suppressed by a control program primarily focused on the use of selective pesticides that target sea lamprey larvae.  A more comprehensive approach to sea lamprey control that targets multiple vulnerabilities in the organism’s life history is needed to further suppress sea lamprey populations.  Recently, a fish guidance system named NEPTUN developed by Procom Systems in Poland has been effective in using vertical electrodes and random patterns of pulsed-DC current at power dams to repel fish.  We highlight four possible NEPTUN applications in sea lamprey control and present laboratory and field experiments that demonstrate efficacy:  1) At existing ineffective sea lamprey barriers, use NEPTUN to block spawning-phase sea lamprey passage until updates can occur; 2) At barrier-integrated traps with low spawning-phase sea lamprey capture efficiencies, use NEPTUN as a non-physical lead to improve trapping efficiency; 3) In streams without barriers, use NEPTUN as a non-physical lead to direct spawning-phase sea lamprey  into portable traps; and 4) direct downstream migrating transformed-phase sea lampreys into traps.  Experiments in a laboratory environment demonstrate that random pulses of low DC voltage effectively blocked spawning-phase sea lamprey migration and directed spawning-phase sea lampreys toward a trap in a laboratory environment.  Results of in-stream field experiments are currently being conducted and will be described in detail.