Hook Wound Longevity and Use as an Indicator of Largemouth Bass Catch‐and‐Release Angling Pressure

Abstract

Largemouth Bass Micropterus salmoides (hereafter, “bass”) is a popular sport fish primarily targeted for catch‐and‐release angling. Hook wounds obtained during angling may provide a short‐term mark that could provide an estimate of angling pressure. However, assessments of hook wound detection and longevity and the relationship between the proportion of bass with hook wounds and angler catches are needed before this mark can be validated. We conducted an experimental evaluation to determine the detectability and longevity of hook wounds in bass angled with two different lure types (single hook and crankbait) during May and July, 2015. Next, we evaluated the proportion of bass displaying hook wounds and the frequency of hook wounds in five mouth locations for 369 bass captured during 16 tournaments. Finally, we evaluated the relationship between the number of bass captured at tournaments and the proportion of bass with hook wounds captured by means of electrofishing to demonstrate the application of this technique in the assessment of angling pressure. Hook wounds were detected in 100% of experimentally angled bass on the day of capture. The lowest detection (73%) occurred on day 3, and wounds were detected in 91% of the bass on day 7. In May, 27% of hook wounds were healed (i.e., not detected for the remainder of the observation period) by day 6, whereas 12% of hook wounds were healed by day 6 in July. Hook wounds were detected in 84% of bass captured in tournaments and were evenly distributed among five mouth locations. Finally, the proportion of bass exhibiting hook wounds and captured by means of electrofishing between April and October ranged between 5% and 46% and was positively related to the number of bass weighed at the tournaments. Combined, our results indicate that hook wounds could represent a useful short‐term method of marking for estimating angling pressure.

Tournament and non-tournament anglers have little effect on a largemouth bass population compared to natural mortality

“…For example, annual fishing mortality rates of adult largemouth bass in a Connecticut Lake was estimated as 0.42 (Edwards et al 2004), harvest rates in a Florida Reservoir were estimated as high as 0.60 (Kerns et al 2016). Even when anglers release black bass alive, they can still experience mortality because of hooking wounds (Cooke et al 2003;Fernholz et al 2018), exhaustion during capture (Schreer et al 2001), air exposure ), warm temperatures (Suski et al 2003), and handling stress (Williamson et al 1986).…”

Effects of live-release tournament regulation changes for an Iowa Largemouth Bass population

“…Despite tournament anglers' best efforts to reduce angling stress and increase survival of released bass during catch and release tournaments, angling, handling, and retaining bass in livewells until weigh-in can result in pre-or post-release mortality Gravel et al 2008;. Pre-release mortality (hereafter referred to as initial mortality) from live-release tournaments can be caused by hook injury, epithelial damage, prolonged confinement in live-wells or other containers during the weigh-in process, and high water temperatures Fernholz et al 2018). Cryptic sources of mortality, such as post-release mortality (hereafter referred to as delayed mortality) from live-release tournaments are typically caused by extended exposure to poor water quality, low oxygen conditions, extensive handling, and high water temperatures .…”