Response of Asian Carp to Firing of Seismic Water Guns

Bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molotrix) have expanded their range into northern Illinois and Indiana and threaten to enter the Great Lakes through two potential vectors.  We examined responses of juvenile silver carp to discharge of seismic waterguns in 0.5-ha ponds to test whether waterguns might be deterrents in natural environments to augment electrical barriers to upstream migration.  We conducted five experiments in 2012 in which a known number juvenile silver carp were allowed to acclimate, then subjected to several periods of firing.  In spring 2013 we conducted three trials using bighead carp and three using silver carp.  An array of video cameras deployed above the pond and two arrays of 200-kHz hydroacoustic transducers deployed in pairs to create a curtain of sound from surface to bottom were used to detect movement of fish before, during, and after firing periods.  Detection rates are compared between detection gears, among firing periods, and between diel periods (day and night).  Results suggest greater activity during darkness and reduced activity during firing periods.  Field experiments where these species exist are underway to determine if bighead and silver carp can be excluded from areas using water guns.