Behavioural adjustment of fish to temporal variation in fishing pressure affects catchability: an experiment with angled trout

Abstract

In passive fisheries, such as angling, the fishing success depends on the ultimate decision of a fish to ingest the bait, based on an individual’s internal state, previous experience, and threat perception. Fish surviving capture by anglers are known to be less vulnerable, and catch rates usually quickly decline with increasing fishing effort. Previous theoretical models have thus suggested fishing closures as a means to recover responsiveness of fish to angling gear and maintain catch rates, yet empirical support remains limited. In a controlled replicated pond experiment, we evaluated the effects of temporal variation in fishing pressure on catch rates of rainbow trout (Oncorhynchus mykiss) by simulating short-term fishing closures. Fishing closures increased catch rates and population-level catchability by reducing threat perception at the population level and allowing released individuals to return to a vulnerable state. Our experimental results show that periodic fishing closures benefit catch rates but at the risk of aggravating the likelihood of overharvesting.

Hook Avoidance Induced by Private and Social Learning in Common Carp

“…It will be an important question for future studies whether a single social hooking event would be remembered for longer time frames or get lost through fading memory over time. As recurrent negative stimuli may be important when shaping the learning response in fish with direct experience (Coble et al 1985), repeated angling exposure (Koeck et al 2020), an increase in magnitude of the stressor (Barton 2002), and the social learning mechanism (Brown and Laland 2003;Rendell et al 2011) might affect whether or not decreased vulnerability will be retained in the social individuals for a longer time period.…”

“…Catch and release has sublethal effects on fish (e.g., inducing hooking-related injuries and physiological stress responses; Pankhurst and Dedual 1994;Meka and McCormick 2005), which can lead to behavioral changes in released fish, such as decreased activity (Schreer et al 2005;Halttunen et al 2010;Klefoth et al 2011) and altered feeding (Stålhammar et al 2012). The experience of being captured and released can also induce hook avoidance learning, which has been documented in as diverse species as Common Carp (Beukema 1970a;Raat 1985;Klefoth et al 2013), Northern Pike (Beukema 1970b;Arlinghaus et al 2017aArlinghaus et al , 2017b, Largemouth Bass (Anderson and Heman 1969;Wegener et al 2018;Louison et al 2019b), and Rainbow Trout Oncorhynchus mykiss (Askey et al 2006;Lovén Wallerius et al 2019;Koeck et al 2020). Hook avoidance learning decreases overall angling vulnerability and can penalize future catch rates (Beukema 1970a(Beukema , 1970bvan Poorten and Post 2005;Klefoth et al 2013;Monk and Arlinghaus 2017).…”

“…Mechanistically, hooked and released fish learn from private hooking experiences (Beukema 1970a;Raat 1985;Louison et al 2019b;Lovén Wallerius et al 2019). In addition, it has been suggested that fish may also rely on socially transmitted cues that indicate threat, such as behavioral cues or the release of alarm pheromones (also called Schreckstoff) through injury of the epidermis (Pitcher 1993), to avoid future capture by angling (Beukema 1970a;Klefoth et al 2013;Lovén Wallerius et al 2019;Koeck et al 2020) or other fishing gear (Brown and Warburton 1999;Brown and Laland 2002). Compared to the effects of private learning (i.e., direct effects of hooking), it remains largely unexplored to what extent social learning (i.e., the experience of watching conspecifics being caught) can affect individual vulnerability to capture in the future.…”

Socially induced stress and behavioural inhibition in response to angling exposure in rainbow trout

“…In addition to potential lethal impacts, C&R can produce multiple sublethal stress responses, including elevated plasma concentrations of cortisol (Meka & McCormick, ; Pankhurst & Dedual, ), increased cardiac activity (i.e., heart rate, cardiac output and stroke volume) (Anderson et al, ; Cooke, Philipp, Dunmall, & Schreer, ; Cooke, Schreer, Dunmall, & Philipp, ) and behavioural changes for a certain period following the release (Klefoth, Kobler, & Arlinghaus, ; ). As a consequence, individual fish can develop hook avoidance behaviour through private experiences of hooking (Askey, Richards, Post, & Parkinson, ; Beukema, , ; Klefoth, Pieterek, & Arlinghaus, ; van Poorten & Post, ; Raat, ; Young & Hayes, ).…”

“…As a consequence, individual fish can develop hook avoidance behaviour through private experiences of hooking (Askey, Richards, Post, & Parkinson, ; Beukema, , ; Klefoth, Pieterek, & Arlinghaus, ; van Poorten & Post, ; Raat, ; Young & Hayes, ). In addition, population‐level catchability has been found to be affected by angling effort without necessarily all fish being hooked and released (e.g., ; Kuparinen, Klefoth, & Arlinghaus, ; Alós, Palmer, Trías, Díaz‐Gil, & Arlinghaus, ; Wegener, Schramm, Neal, & Gerard, ). Experimental pond studies with carp, Cyprinus carpio L. (Beukema, ; Klefoth et al, ; Raat, ), and pike, Esox Lucius L. (Beukema, ), have suggested that social learning might play a role in observed decreases of overall catchability.…”