E. Wilson, L. LaRochelle, A. Petteta, S.J. Landsman, S.J. Cooke
Muskellunge ( Esox masquinongy ) are a popular sportfish across their native and introduced range. Recreational fisheries for Muskellunge are intensively regulated, although there is a strong conservation ethic wherein most of the individuals captured by recreational anglers are released. Despite high voluntary release rates, the influence of angling and air exposure on the post-release behaviour of Muskellunge in the wild remains unclear. Here, we captured Muskellunge from waterbodies in eastern Ontario, Canada using conventional Muskellunge angling gear in water temperatures of 19–27 °C and exposed them to air for different durations of time (none: 0 s, medium: 60–94 s, high: 120–160 s). Captured Muskellunge ( n = 13) were equipped with a novel pop-off biologging package prior to release. Pop-off biologging packages were used to observe swimming activity, depth and water temperature used by Muskellunge for a 10-h post-release monitoring period. No mortalities occurred during the 10-h monitoring period. Longer air exposure durations resulted in elevated swimming activity during the initial 5-h post-release and returned to the non-air exposed treatment behaviour after 6-h post-release. There were no differences in water temperature or depth used by Muskellunge exposed to air compared to those that were not exposed to air. Anglers should aim to keep air exposure periods < 60 s for Muskellunge that are intended to be released to avoid post-release behavioural alterations that result in increased swimming activity. Increased swimming activity observed once released was presumably a strategy used by Muskellunge to help increase blood flow and clear anaerobic by-products that occured as a result of the fight and air exposure period. Avoiding increased swimming activity during the post-release recovery period is important for reducing excessive energetic expenditures that could influence the fitness of fish (e.g., acquiring food).