The Use of Chemical Stimuli in the Control of Asian Carp

We have found that invasive bighead and silver carp are responsive to conspecific pheromones both physiologically and behaviorally.  Asian carp avoid alarm pheromones present in skin extracts as a means of avoiding predators, and are also attracted to chemical cues released by groups of conspecifics as a means of maintaining schooling behavior in turbid water conditions.   Physiological screening assays (EOGs) indicate high sensitivity of the olfactory system for certain hormonal metabolites associated with the sex pheromones and lab behavioral assays verified attraction to them.  In mesocosm tests free ranging silver and bighead carp appeared responsive to caged fish that had been hormonally implanted.  An algal food stimulus was found to be highly stimulatory to bighead and silver carp in mesocosm tests and induced prolonged attraction in the area of release.  Laboratory tests indicated several components of the algal stimulus were highly attractive.  We initiated studies for conditioning wild fish response to feeding stations as a means of inducing aggregations of carp to facilitate harvest.  We are using technologies such as side scan and dual frequency identification sonar and PIT-tag arrays to verify the behavioral effectiveness of chemical lures in the field.