Innovative Technology for Deterrence and Conservation of Marine Mammals Using Non-Lethal Electric Gradients: Updated Results of Field Trials

Marine mammal population expansions have led to a growing number of conflicts and issues among entities that manage marinas and agencies that manage fisheries.  For harbormasters, issues include damage to marina infrastructure and human use conflicts.  For resource managers, issues frequently involve predation on sensitive fish stocks.  We describe an innovative technology to deter California sea lions and Pacific harbor seals using non-lethal fields of pulsed DC.  It evolved from three decades of research on graduated-field fish guidance technology and uses low-energy gradients that irritate, but do not harm animals.  We summarize deterrence trials conducted on harbor seals in British Columbia, Canada (2007) and other in-water trials on captive California sea lions in the U.S. (2008).  We also discuss a successful deployment to deter sea lions from a visitor’s dock in California (2012).  A short video highlights some typical deterrence responses recorded while observing  ~1,000 attempts by animals to repopulate an energized dock segment over a 10-day interval.  The goal of our presentation is to update attendees and resource managers about a non-lethal deterrence technology having the potential to address marine mammal interactions and conflicts in both fisheries applications and public use settings.