Ashley K Lopez
Justin R. Smerud
John A. Tix
Jose Rivera
Nicholas M. Swyers
Marybeth K. Brey
Christa M. Woodley
David L. Smith
Mark P. Gaikowski
Aaron R. Cupp
2021
<p><span>Carbon dioxide (CO</span><sub>2</sub><span>) mixed into water is being explored as a possible management strategy to deter the upstream movements of invasive carps through navigation locks and other migratory pinch-points. This study used two-dimensional acoustic telemetry to assess the effectiveness of dissolved CO</span><sub>2</sub><span> as a chemosensory deterrent to two carp species in a large U-shaped pond. Free-swimming movements of telemetered bighead carp (</span><i>Hypophthalmichthys nobilis</i><span>) and grass carp (</span><i>Ctenopharyngodon idella</i><span>) were documented 24 h before treatment and 24 h during treatments at 60, 121 and 213 mg/L CO</span><sub>2</sub><span> (mean concentrations in pond water). Several behavioral endpoints were then quantified and compared to evaluate deterrence efficacy. In general, results showed that both carp species responded similarly to CO</span><sub>2</sub><span> treatments. Carps consistently relocated into areas away from the injection site and made fewer attempts to re-enter CO</span><sub>2</sub><span> treated areas. On average, CO</span><sub>2</sub><span> treatments reduced mid-line crosses between untreated and treated sides of the pond by 58% at 121 mg/L CO</span><sub>2</sub><span> and 78% at 213 mg/L CO</span><sub>2</sub><span> relative to normal swimming movements recorded before treatment. Fish swim speeds increased significantly when inside the CO</span><sub>2</sub><span> plume during treatments during 213 mg/L CO</span><sub>2</sub><span> trials relative to swim speeds outside the plume, possibly indicative of active searching and avoidance responses. Overall, this study found that CO</span><sub>2</sub><span> altered the behavior of bighead carp and grass carp. Natural resource agencies could consider the CO</span><sub>2</sub><span> concentrations identified in this study to inform future applications to deter invasive carps from locations where they are at-risk to move upstream.</span></p>
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10.1016/j.jglr.2020.10.004
en
Elsevier
Telemetry evaluation of carbon dioxide as a behavioral deterrent for invasive carps
article