Effects of an ensonified bubble curtain and a cyclic sound on blocking 10 species of fishes including 4 invasive carps in a laboratory flume

Four species of invasive carp from Asia are currently advancing up the Mississippi River through its locks and dams. It has been hypothesized that this movement could be blocked in a selective manner by projecting sound projected into locks because carp, like all members of the Ostariophysi, have exceptional hearing. Although previous laboratory studies have shown that a broadband cyclic sound blocks ~ 80% of bighead and common carp, and that this value increases when sound is projected into an air curtain to create an ensonified bubble curtain (EBC), the effectiveness of EBCs at blocking other fishes including carps has not been addressed. To answer this question, the present study examined the responses of 10 fishes including 4 species of invasive carp (bighead, silver, grass, common), 2 native ostariophysians (channel catfish, golden shiner), and 4 native non-ostariophysians (rainbow trout, largemouth bass, bluegill sunfish, lake sturgeon) in a laboratory flume while a cyclic sound was either projected on its own or into a bubble curtain. The EBC, whose sound fields (sound pressure and particle acceleration) were more intense and sharper than sound alone, blocked all 4 carps 92–97% of the time for all 8 trials (i.e. without apparent habituation), while 5 native ostariophysian and non-ostariophysian fishes were also partially blocked 19–89%. In contrast, sound alone significantly blocked only bighead and common carp while affecting the other fishes including the carps to varying extents (− 44–7%). In conclusion, EBCs appear very well suited to block carps.