Strategies for Quantifying Sublethal Effects of Marine Catch-and-Release Angling: Insights from Novel Freshwater Applications
S. J. Cooke, J. F. Schreer, K. M. Dunmall, and D. P. Philipp
Abstract.—Traditional approaches for assessing the effects of catch-and-release angling have focused either on hooking injury, mortality associated with different handling and environmental conditions, or biochemical indicators of short-term stress response and recovery. These methodologies do not permit the collection of real-time data on the sub-lethal effects and recovery period associated with the angling event, nor do they provide information on long-term fitness impacts to angled individuals. The advent of hard-wired, archival, and telemetered technologies capable of collecting information on fish location, locomotory activity, cardiac function, and various environmental parameters provides researchers with powerful methodologies for monitoring the response of individual fish to different stressors. These technologies and approaches have been used primarily with freshwater fishes, but they may be applicable to marine environments. Compared with freshwater systems, there are unquestionably some additional challenges due to unique characteristics of the marine habitat (e.g., depth, vastness, salinity) and behaviors of marine fishes (e.g., migratory patterns). Irrespective of the challenges, fisheries scientists must begin to look beyond hooking mortality as an endpoint for assessing the success of a catch-and-release angling program. Studies need to be conducted that provide real-time information on sublethal physiological effects, disruptions in behavior, and long-term impacts on the fitness (lifetime reproductive success) of released fish. Despite the fact that managers are usually concerned with population level effects, additional individuallevel comprehensive studies are required before we can attempt to understand if and how catch-and-release angling affects populations.