Influence of artificial lure hook type on hooking characteristics, handling, and injury of angled freshwater gamefish

Abstract

Catch-and-release is practiced in recreational fisheries under the premise that released fish will survive with negligible injury and stress. However, hooking injuries may prevent that outcome from being realized. One way to potentially minimize injuries and maximize survival in angled fish is to replace treble hooks on hard plastic lures with single hooks, but the effectiveness of this tactic has yet to be tested. Our study investigated if replacing treble hooks with single hooks on hard plastic lures reduced injuries and handling for angled Northern Pike (Esox lucius), Smallmouth Bass (Micropterus dolomieu) and Largemouth Bass (Micropterus salmoides). Furthermore, we compared fish handling (i.e., need for use of hook removal gear) and injuries between fish that were captured with barbed and barbless hooks. Fish were angled using three types of conventional hard plastic lures (i.e., crankbaits, jerkbaits, and lipless crankbaits). Upon landing, total length of the fish, an array of hooking characteristics (i.e., number of hook points in the fish, anatomical hooking location(s)), and reflex impairment were recorded. Analyses revealed that using barbless J hooks on all lures yielded the shortest unhooking times for all species. For Smallmouth Bass caught on both crank and jerk baits, J hooks tended to result in more shallow hooking than treble hooks. Barbless treble hooks were more likely to be embedded in a sensitive location (e.g., foul hooked, gullet, gills, and/or eyes) compared to barbless J hooks in Smallmouth Bass. No other significant differences in hook types and anatomical locations were found for other species. Hook type and lure type did not influence reflex impairment or survival for any of the species. Using J hooks, especially barbless ones, on lures that traditionally have treble hooks should be considered when encouraging best angling practices for the freshwater gamefish studied here to expedite release, although the extent to which this influences mortality remains unclear.

Introduction

Recreational fishing is a popular activity around the globe. Although some fish are harvested, it is increasingly common that fish are released to comply with regulations or as a voluntary action linked to a conservation ethos (Arlinghaus et al., 2007). An assumption that underpins catch-and-release (C&R) as a conservation and management strategy is that mortality is low and that any injuries or sublethal disturbances are short lived (Wydoski, 1977; Cooke and Schramm, 2007). However, a growing body of research reveals that not all fish survive angling events (Muoneke and Childress, 1994; Bartholomew and Bohnsack, 2005; Arlinghaus et al., 2007). Mortality rates are highly variable and context dependent, (Bartholomew and Bohnsack, 2005; Brownscombe et al., 2017), varying widely depending on environmental factors, angler behaviour, gear type used, and species-specific responses to stress (reviewed in Brownscombe et al., 2017).

Across C&R studies, a common factor has been identified as being the single largest determinant of fish survival - anatomical hooking location, whereby fish hooked in vital areas (e.g., the gullet and/or gills) tend to experience higher mortality and bleeding compared to fish hooked in the jaw (e.g., Pelzman, 1978; Taylor and White, 1992; reviewed in Bartholomew and Bohnsack, 2005). Hooking location can be influenced by a variety of factors including lure/bait type, gear type, and angler experience (Muoneke and Childress, 1994). For example, organic baits tend to result in deeper hooking locations than artificial baits while smaller baits tend to result in deeper hooking locations than larger baits (Arlinghaus et al., 2008; Fobert et al., 2009). Novice anglers are also more likely to deeply hook fish in comparison to more experienced anglers (Dunmall et al., 2001).

Hook type and hook number have also been shown to influence physical damage in recreationally angled fish (Muoneke and Childress, 1994; Brownscombe et al., 2017). For instance, circle hooks tend to yield shallower hooking locations compared to J hooks (Cooke and Suski, 2004). Many studies on salmonids have found that using single hooks on lures results in decreased mortality compared to the use of treble hooks (Hunsaker et al., 1970; Matlock et al., 1993; Nuhfer and Alexander, 1992; Warner, 1979). Similar findings have been found with Northern Pike (Esox lucius), where using a single hook on lures instead of a treble hook tended to result in less mortality (Burkholder, 1992). A recent study has suggested that using lures with fewer hooks and/or single hooks may help to reduce unhooking time and minimize air exposure in Largemouth Bass (Micropterus salmoides; Clarke et al., 2020). However, that study failed to systematically vary hook type and the presence of barbs on the same lure types. Single hooks have been shown to cause less injury and lower mortality in comparison to treble hooks in some contexts (Muoneke and Childress, 1994; Bartholomew and Bohnsack, 2005). However, there has been very little work done evaluating the effects of using a single hook on hard plastic fishing lures commonly used by anglers when targeting freshwater gamefish (Cooke and Suski, 2005). Hook type and number can also influence handling time and need to use different hook removal gear (e.g., pliers rather than bare hands), which is another factor to consider when assessing impacts on recreationally angled fish (Brownscombe et al., 2017).

Traditionally, most artificial hard body lures use treble hooks, but this tradition has been slowly changing in the angling community. There are discussions in online forums as well as increasing number of fishing media stories about the merits of replacing treble hooks on hard bodied lures with single J style hooks (e.g., Landesfeind, 2018; Waters, 2019). Northern Pike, Smallmouth Bass (Micropterus dolomieu), and Largemouth Bass are species that are traditionally caught with treble hooks when using hard plastic lures. As such, investigating the impacts of using single J hooks could provide insight on whether there is merit in replacing treble hooks on lures. The use of barbless hooks has also become a common practice (sometimes voluntary or mandated) in some jurisdictions as some studies suggest barbless hooks reduce injury during catch and release angling events (Meka, 2004; Bartholomew and Bohnsack, 2005). Yet, beyond salmonids (see Schill and Scarpella, 1997), there is relatively little known about the extent to which barbless hooks benefit fish caught on lures.

The primary objective of this study was to investigate if replacing treble hooks on lures with single hooks influenced hooking location, injuries and fish handling (i.e., use of different hook removal gear) and the extent to which these outcomes are moderated by barbs. To do so, we focused on hard plastic lures (i.e., crankbaits, jerkbaits, and lipless crankbaits) which are commonly used to target freshwater gamefish, and for which barbed treble hooks are the default hook type at time of purchase. This study compared treble hooks (barbed and barbless) as well as J hooks (barbed and barbless) on the different lure types. Three species were included in the study (Northern Pike, Smallmouth Bass, and Largemouth Bass) representing some of the most popular freshwater gamefish in North America. Given interspecific variation in anatomy and hook performance we did not quantitatively compare outcomes among different species.