Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science 15:e10238, 2023 © 2023 The Authors. Marine and Coastal Fisheries published by Wiley Periodicals LLC on behalf of American Fisheries Society. ISSN: 1942-5120 online DOI: 10.1002/mcf2.10238
ARTICLE
Postrelease Mortality of Angled Tarpon in Puerto Rico Laura B. Horowitz, Peter J. Allen
, J. Wesley Neal, and Sandra B. Correa*
Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Box 9690, Mississippi State, Mississippi 39762, USA
Abstract
Tarpon Megalops atlanticus is a popular and economically important inshore sport fish in Puerto Rico, and the pursuit of this species by local anglers and tourists contributes to the economy. This species is managed as a no-take fishery, which aims to preserve populations by catching and releasing fish that would otherwise be subjected to harvest and removal from the population. The approach assumes minimal mortality and/or reduced fitness of released fish, yet the process of angling can produce many sublethal side effects or direct mortality. In this study, charter angling for Tarpon in the San Juan lagoon system in Puerto Rico was examined to determine postrelease mortality. Angled fish were externally tagged with acoustic transmitters and relocated periodically to determine the fate after release. Postrelease mortality was at least 4.5% (two fish observed dead) and at most 18.2% (observed dead plus classified dead based on lack of movement; confidence interval [CI] = 7.5–28.9%). Some tag loss was observed, which could have artificially elevated classified mortality estimates. Potential factors that contribute to mortality are discussed and compared to the literature. Hook type, gear action, landing procedures, and air exposure were key areas of possible improvement. Recommendations to minimize fish harm during angling include the use of heavier action gear to reduce fight time, a circle hook requirement for live bait to reduce deep hooking, maintaining fish in the water during landing and photography, and limiting air exposure to 2 min or less if fish are removed from the water.
The goal of catch-and-release angling is that captured fish survive to be caught again (Pollock and Pine 2007). This requires that fish are not physiologically compromised after release (Orr 2009). Despite the intent of catchand-release practices, angling can cause acute stress and physical damage to fish, with potential lethal or sublethal consequences (Mazeaud et al. 1977; Skomal 2006). Visible injuries may include hooking wounds, physical deformities from repetitive hooking and handling, and bacterial/fungal infections (Meka 2004). Subsequent to capture, fish can experience respiratory issues and compromised immune systems, leading to behavioral changes (Cooke et al. 2002; Wilson et al. 2014). Other physiological impairments include damage to the reflex response, increased risk of predation, and decreased individual fitness (Campbell
et al. 2010; Brownscombe et al. 2017). These stressors may act individually or synergistically to result in the death of released fish. Mortality may vary by duration and magnitude of the stressors (Meka and McCormick 2005) and are influenced by gear type (Sass et al. 2018), environmental conditions (Suski et al. 2006), and postcapture handling and release practices (Guindon 2011). Acoustic telemetry is often used to determine in situ mortality over a period of hours to weeks following release (Prince et al. 2002; FFWCC 2013). For example, Red Snapper Lutjanus campechanus tagged with acoustic transmitters demonstrated angling mortality occurred within 72 h following release (Eberts and Somers 2017). Results from acoustic telemetry of Bonefish Albula vulpes
*Corresponding author: sbc257@msstate.edu Received May 25, 2022; accepted January 14, 2023 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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