Using short-term postrelease behavior to assess novel methods of facilitated recovery for angled Smallmouth Bass

Objective Catch-and-release recreational angling is predicated on the idea that fish soon return to normal activity following release, yet little consideration is given to the physiological requirements for recovery from such an interaction. In recent years, assisted recovery techniques have gained attention by anglers with the goal of returning fish to the wild in better condition. Here, we assess the efficacy of different facilitative recovery techniques for Smallmouth Bass Micropterus dolomieu. Methods We used biologgers to assess the short-term (12 min) postrelease depth used, water temperature used, and swimming activity of Smallmouth Bass that were exposed to simulated catch-and-release stressors and evaluated the efficacy of different assisted recovery techniques. The recovery techniques included holding fish in relatively still freshwater (i.e., live well) or holding fish in flowing freshwater (in a flow chamber) for a period before release. There were also control Smallmouth Bass that were never exposed to air and released immediately, and another group of Smallmouth Bass that were exposed to air and released immediately. Results The overall postrelease depths and water temperatures that were used by Smallmouth Bass did not differ significantly across the treatment groups. Smallmouth Bass across most of the treatments had a similar postrelease trajectory by seeking deeper, cooler water immediately postrelease, with the exception of Smallmouth Bass that were exposed to air and subjected to 5 min in the flow chamber, which remained at a consistent depth and temperature throughout the monitoring period. Swimming behavior upon release differed significantly across the treatments, with the fish that were exposed to air that were not recovered spending more time engaging in slow swimming and less time engaging in fast swimming than the control Smallmouth Bass or the Smallmouth Bass that were subjected to the different recovery techniques. Notably, the Smallmouth Bass that were recovered using the 15-min flow chamber spent significantly more time engaging in fast swimming and less time engaging in slow swimming than those that were exposed to air. Conclusions Our study indicates that recovery techniques following air exposure, specifically the 15-min flow chamber, can improve the recovery of Smallmouth Bass that are intended for release. Recovery techniques may not be necessary for Smallmouth Bass that are not exposed to air and immediately released. Future research could focus on determining the minimum time that is needed in different recovery techniques to improve the condition prior to release. It would also be beneficial to do this across a range of water temperatures with fish that are captured from different depths and with other recreationally targeted species.