Capture technique and fish personality: angling targets timid bluegill sunfish,Lepomis macrochirus

Abstract

Size-selective harvesting associated with commercial and recreational fishing practices has been shown to alter life history traits through a phenomenon known as fishing-induced evolution. This phenomenon may be a result of selection pathways targeting life-history traits directly or indirectly through correlations with behavioral traits. Here, we report on the relationship between individual differences in behavior and capture technique (beach seining versus angling) in wild-caught juvenile bluegill sunfish ( Lepomis macrochirus ). Both fish caught by using a seine net (seined) and fish caught by using a lure (angled) were individually tested under standardized laboratory conditions for their boldness, water-column use, and general activity. Observed inter-individual differences in boldness were strongly correlated with method of capture in the wild. Fish caught by angling were more timid and had fewer ectoparasites than fish caught using a seine net. However, this relationship did not carry over to an experiment in a large outdoor pool with seine-caught, individually tagged wild fish, where bolder individuals were more likely to be angled in open water away from refuges than more timid individuals, based on their previously assessed boldness scores. Our study is both novel and important, as it describes the relationship between capture technique and boldness in a natural population and underscores the potential risk of sampling biases associated with method of animal capture for behavioral, population, and conservation biologists.

Behavioural variation in Eurasian perch populations with respect to relative catchability

“…consistent behavioural differences among individuals across time and different contexts, have been of high interest among behavioural ecologists during the last decade (Sih et al 2004;Réale et al 2010;Stamps and Groothuis 2010;Mittelbach et al 2014). Recently, they have also received increasing attention in applied contexts, such as among studies on harvesting-induced evolutionary changes (Wilson et al 2011;Binder et al 2012;Härkönen et al 2014). In particular, selective harvesting of certain behavioural types has been predicted to impose fishing-induced selection on fish personality (Lewin et al 2006;Uusi-Heikkilä et al 2008;Conrad et al 2011).…”

Selective exploitation of spatially structured coastal fish populations by recreational anglers may lead to evolutionary downsizing of adults

“…More complex exploitation patterns with respect to traits selected by fishing are conceivable for passively operated fishing gears (where the odds of capturing a fish depends on a fish's decision to attack and/or ingest baited hooks), such as recreational angling (Uusi-Heikkilä et al 2008). In many recreational harvesting situations, such as hook-and-line angling, selection of a range of behavioural, physiological and life-history correlated traits is conceivable (Cooke et al 2007, Uusi-Heikkilä et al 2008, Redpath et al 2009, Wilson et al 2011, Sutter et al 2012. The resulting complexity of selection pressures on a range of traits that are correlated with the overarching trait 'vulnerability to fishing' suggests that the selection differentials caused by recreational angling may not necessarily show the expected sign.…”

Hormonal responsiveness to stress is negatively associated with vulnerability to angling capture in fish

“…Previous work has sought to link this risk-taking behavior to angling vulnerability, and results have been inconsistent. Some studies indicate that bolder and more exploratory individuals are more vulnerable to capture by anglers (Härkönen et al, 2014(Härkönen et al, , 2016Klefoth et al, 2013); other work has found bold individuals to be less vulnerable to angling (Wilson et al, 2011); and still other work has found no connection between boldness and angling vulnerability (Kekäläinen et al, 2014;Vainikka et al, 2016). Inconsistent findings linking boldness to angling vulnerability may be due to differences in methodology across studies (Beckmann and Biro, 2013), or may indicate that a relationship between boldness and vulnerability is context dependent and may fluctuate depending on factors such as the species in question or the time of year (for instance, during the spawning season, vulnerability to angling may depend to a greater degree on factors related to aggressiveness; see Sutter et al, 2012).…”

“…For example, previous work has shown that bolder and more active individuals may be more likely to be caught on hookand-line gear (Härkönen et al, 2014;Klefoth et al, 2013), while individuals with higher growth rates have been found to be more vulnerable to commercial netting (Biro and Post, 2008). It is important to note that, while previous work has independently examined the correlation of boldness (Wilson et al, 2011) as well as metabolic rate (Redpath et al, 2010) with angling vulnerability, no studies have taken an integrative approach to simultaneously examine the relative influence of behavior, metabolic rate and hormones in driving the likelihood of capture. Defining these relationships is of critical importance in determining which characteristics may be under selective pressure, and what types of evolutionary alterations we can expect to see in populations exploited by recreational anglers.…”