Behavioural Response of Juvenile Common Carp (Cyprinus carpio) and Juvenile Channel Catfish (Ictalurus punctatus) to Strobe Light

The movement of fish can be regulated by behavioural manipulation through non-physical barrier systems. Aquatic invasive species are becoming one of the major management issues in North America, and threaten native aquatic ecosystems, including freshwater fish. Placements of non-physical barriers in waterways can help disrupt the movement of invasive fish. This study examined the effect of a strobe-light stimulus on the avoidance behaviour of two proxy species, juvenile common carp (Cyprinus carpio) and juvenile channel catfish (Ictalurus punctatus), in a controlled laboratory environment. For each species, three sequential treatments of pre-stimulus, strobe-light stimulus, and post-stimulus for 30 min periods were recorded on acclimated groups of 5 juvenile common carp and 5 juvenile channel catfish using 15 and 13 replicates, respectively. The distribution of juvenile common carp individuals throughout the tank did not change significantly with treatment, nor did cohesive grouping behaviour. Similarly, there were no significant differences across experimental treatments in average location/distance of juvenile channel catfish relative to the strobe light or degree of cohesion in response to the strobe light. Non-physical barriers have been widely reported to vary between species and environmental conditions. These results suggest that strobe lights evoke no avoidance or attractive responses in juvenile common carp and juvenile channel catfish, and will likely not be an effective barrier to inhibit movements of juvenile invasive fishes.