Circle Hooks Research Articles

Evaluating the conservation benefit of circle hooks for the Atlantic Striped Bass recreational fishery

AbstractObjectiveThe Striped Bass Morone saxatilis is one of the most sought‐after recreational fish species along the US Atlantic coast. Regulations and a strong conservation ethic among anglers make Striped Bass among the most frequently released coastal marine fishes. A recent rule requires anglers to use circle hooks when targeting Striped Bass with natural baits, yet the conservation benefit of this action remains unclear.MethodsWe used acoustic telemetry to monitor the fate of Striped Bass that were recreationally caught with baited hooks (n = 349) and to estimate the influence of various biological (fish size), fishery (fight time, handling time, hook location, bait type, and hook type), and environmental (water temperature and air temperature) variables on postrelease survival.ResultA semi‐quantitative score of fish release condition was the single best predictor of mortality. A broader dataset that included untagged fish (n = 716) was used to identify the best predictors of fish release condition, which included hook location and handling time.ConclusionContrary to expectations, the circle hooks used in this study did not result in lower release mortality than conventional J‐hooks.

Impact of hook choice, fish size, and water temperature on hooking depth, injury, and postcapture physiology in Channel Catfish

AbstractObjectiveCatch‐and‐release angling is an oft‐practiced conservation tool involving the release of captured game fish either due to harvest regulations or conservation ethic on the part of the angler. Central to this practice is the assumption that released fish survive; however, a large body of work has shown that postrelease mortality can occur, especially if fish are injured during the capture process. In this study, we examined hooking location, bleeding, injury rates, and postcapture physiology in Channel Catfish Ictalurus punctatus, a popular game fish species.MethodsA total of 83 Channel Catfish were angled from a lake in southern Illinois using conventional rod‐and‐reel techniques with one of four hook types (J‐hook, shiner, circle, and octopus). Captured fish were then assessed for hooking depth, bleeding, and injury. Subsequently, a subset of 40 fish were additionally held for 4 h in submerged totes before being tested for reflex responsiveness and undergoing a blood biopsy for glucose and lactate levels.ResultCircle and octopus hooks reduced hooking depth in Channel Catfish compared with J‐hooks and tended to reduce postcapture bleeding as well. Postholding physiological results showed no effect of hook type on blood lactate or glucose levels, and reflex impairment was very rare (only a single fish was impaired for any reflexes 4 h postcapture).ConclusionOverall, the results of this study suggest that the use of circle hooks reduce the likelihood of deep hooking and injury in Channel Catfish, though Channel Catfish, at least in the short term, were physiologically resilient to the effects of capture.

Factors influencing the at‐haulback mortality of striped marlin Tetrapturus audax caught by tuna longline fishery in the western Indian Ocean

Abstract Striped marlin (Tetrapturus audax) is an oceanic pelagic migratory fish. The stock status of striped marlin in the Indian Ocean is now considered to be overfished and subject to overfishing. Quantifying the level of at‐haulback mortality caused by longline fisheries for tuna and tuna‐like species is critical to reducing fishing pressure and protecting the fate of billfish stocks. This study was based on data from 2482 longline fishing operations recorded by Chinese observers in the western Indian Ocean from 2012 to 2019. The dataset includes information on the survival status of 774 striped marlin and their corresponding details. We used a generalized linear model (GLM) to analyse the level of at‐haulback mortality and its potential influencing factors. The results indicate that the distribution of 774 striped marlin had a lower jaw‐fork length (LJFL) range from 130 to 220 cm, and 51.5% of the specimens died at the time of haul‐back. The GLM model revealed that quarter, sea‐surface temperature (SST), hook type, LJFL, chlorophyll (CHL) and longitude had significant effects on at‐haulback condition when the fish were retrieved on board, with the quarter and sea surface temperature having the most significant effects. The interaction term between hook type and LJFL also had a significant effect on at‐haulback mortality, with the model predictions showing that mortality increased with LJFL when using circle hooks but decreased when using Japanese tuna hooks. There has been limited observational analysis of hooking mortality rates for striped marlin, and the present study may provide an important reference for the conservation and management of striped marlin stocks in the Indian Ocean.

Post‐release mortality of line‐caught snapper Chrysophrys auratus depends on hook site and capture depth

AbstractCatch‐and‐release angling is common in recreational fisheries, but post‐release mortality (PRM) may be high. We conducted a controlled field experiment to estimate mortality of released snapper Chrysophrys auratus. Recreational fishers caught 960 snapper from three depth strata (<15, 15–25, 26–40 m) that were either lip‐hooked, foul‐hooked or gut‐hooked. A bottom longline vessel caught 162 lip‐hooked fish in shallow water to serve as controls. Fish were held in 15‐m deep holding nets. All control fish and 80% of treatment fish survived, with anatomical hook site and capture depth significantly predicting mortality. Probability of mortality was lowest for lip‐hooked fish in shallow water (5 m = 0.00, 95% CI [0.00, 0.03]), but increased rapidly to 20 m (0.24, 95% CI [0.2, 0.3]). Mortality of foul‐hooked fish increased steadily with depth from 0.05 (95% CI [0.00, 0.78]) at 5 m to 0.65 (95% CI [0.13, 0.96]) at 40 m. Gut‐hooking resulted in high mortality at all depths but a low sample size resulted in high uncertainty of estimates. Our results indicate that snapper PRM can be reduced by fishing in shallow water and by mitigating gut‐hooking, possibly by using large circle hooks.

Vulnerability status and efficacy of potential conservation measures to reduce tuna fishery bycatch of the Critically Endangered East Pacific leatherback turtle Dermochelys coriacea

Industrial tuna and artisanal fisheries targeting multiple species in the eastern Pacific Ocean (EPO) interact with the Critically Endangered East Pacific (EP) leatherback turtle Dermochelys coriacea. In 2021, a revised Inter-American Tropical Tuna Commission (IATTC) resolution on sea turtles aimed to reduce sea turtle bycatch in EPO industrial tuna fisheries and ensure their safe handling and release. A new ecological risk assessment approach—Ecological Assessment for the Sustainable Impacts of Fisheries (EASI-Fish)—was used to assess vulnerability status and to better understand the potential efficacy of 70 scenarios that compared simulated conservation and management measures (CMMs) for EPO industrial (purse-seine and longline) and artisanal (longline and gillnet) fisheries to the status quo in 2019. In 2019, a fishing mortality proxy (F̃2019) and the breeding stock biomass per recruit (BSR2019) exceeded precautionary biological reference points (F80% and BSR80%), classifying the stock as ‘most vulnerable’. Industrial and artisanal longline fisheries had the highest impacts because they had the highest areal overlap with the modelled EP leatherback distribution. Of the 70 CMM scenarios, 42 resulted in significant improvements in vulnerability status (i.e. to ‘least vulnerable’). The use of large circle hooks, finfish bait, and best handling and release practices each decreased vulnerability; however, the most effective scenarios involved using these 3 measures in concert. The benefits predicted from EASI-Fish for CMM scenarios assume full compliance and attaining the modelled levels of efficacy, our modelling provides stakeholders with evidence-based recommendations to address key threats to EP leatherback turtles to improve their conservation status by reducing fishing impacts.

Hook Types Influence The Catch Effectiveness, Injuries, and Survival Rates of Fishes in Recreational Fishing

The physical damage inflicted on captured fish in recreational fishing activities tends to be influenced by hook type. Therefore, the present study aims to investigate the suitability of hook type for catching fish as well as the evaluation of injuries and survival rates after catch-and-release. The sampling was conducted at a recreational fish pond situated at Universiti Putra Malaysia Bintulu Sarawak Campus from July until November 2022. Three sets of fishing rods with two types of hooks (circle hook & octopus hook) were used in this study. The catch efficiency, injury level, and survival rates of both types of hooks were assessed. A total of 41 and 22 fish were successfully caught using circle hooks and octopus hooks, respectively. Of the total fish caught, 39 out of 41 and nine out of 22 of the fishes caught were tilapia. The hooking location (non-critical area) of octopus hooks and circle hooks on the tilapia was approximately 100% and 81.8%, respectively. A total of 15.38% of hooks are located within the critical area (gills) of tilapia when using the circle hook and none for octopus hooks. There was 100% mortality in fish hooked in the critical area, for instance, hooks pinned inside gills. This occurrence may relate to the shape of the circle hook whereby the length of the gape is shorter in comparison to the octopus hook. Now when fish ingested the bait, the hook easily entered deeper areas of the fish’s mouth, which led to severe damage. Thus the present study recommends the use of octopus hooks in recreational fishing to reduce fish mortality rate for catch and release excursions. The results obtained from this study will be useful baseline input for recreational anglers to improve C&R practices in Malaysia.

Influence of four hook types across four hook removal tools, including bare hands, on the effectiveness of hook removal and reflex impairment of Bluegill (Lepomis macrochirus) captured from a lake in Eastern Ontario

AbstractHook removal devices have been developed to enable rapid release of angled fish, yet little research has evaluated their effectiveness and potential for injury among hook types. We compared the performance of hook removal tools and bare hands with four hook types on freshwater Lepomid sunfish. Dehooking performance was assessed using hook removal time, unhooking difficulty, degree of tissue damage at the hooking location, and immediate reflex impairment. Unhooking difficulty was positively related to hooking depth. Unhooking difficulty was lowest for hemostats and the mechanical dehooking device; however, the mechanical dehooking device caused the largest tearing of mouth tissue. Unhooking difficulty was the main driver for hook removal time, tissue tear length, and overall reflex impairment. Hooks that were harder to remove caused higher reflex impairment. Hook type had little influence on the effectiveness of hook removal tools, although circle hooks were more difficult to remove and caused greater injury when using tools. Although use of hook removal tools can be beneficial for fish that are released, more research is needed on more species targeted by recreational anglers, and more hook removal tools. We suggest that hemostats should be used to remove hooks from fish to reduce unhooking difficulty, tissue tears, long air exposure, and thereby to increase the welfare of the fish.

A review of reported effects of pelagic longline fishing gear configurations on target, bycatch and vulnerable species

Abstract A meta‐analysis of 40 publications totalling 59 experiments was undertaken to review and assess the effects of changing the hook (circle vs. J‐hooks or tuna hooks), bait (fish vs. squid) and leader (wire vs. nylon) type on retention and at‐haulback mortality rates of teleosts (tunas and billfishes), elasmobranchs and sea turtles caught on shallow‐set and deep‐set pelagic longline fisheries. Circle hooks are a promising approach to mitigate the impact of pelagic longline fisheries on sea turtles, as they reduced sea turtle retention rates. The adoption of circle hooks would, however, also lead to a decrease in swordfish retention, the main target species of shallow‐set pelagic longlines. Using fish as bait resulted in lower retention rates of sea turtles, highlighting that option as an additional measure to further mitigate sea turtle bycatch. The bait type had non‐significant effects on sharks, except for blue shark and shortfin mako, for which at‐haulback mortality rates were significantly higher with fish bait. The use of nylon leaders instead of wire leaders could serve as a conservation measure for sharks, as they reduced the retention of blue shark without adversely impacting the catches of swordfish. The results on the effect of the leader material types should, however, be interpreted with caution owing to the limited information available reporting on leader material effects. When considering future research directions, priority should be given to experimental field work on the effects of leader material and on deep‐set longlines. Evaluating the post‐release survival of species should also be a priority.

Effects of gear modifications in a North Atlantic pelagic longline fishery: A multiyear study.

The threat of population declines caused by pelagic longline fisheries in the Atlantic has increased the concern to find strategies that minimize the bycatch and mortality of non-target marine animals. Gear modification, such as the use of circle hooks instead of conventional J-hooks, has been identified as an effective bycatch reduction strategy in different pelagic longline fisheries around the world. This study aimed to verify the effectiveness of the use of circle hooks by quantifying catch rates, relative size selectivity, and anatomical hooking position for the most common target species (swordfish, Xiphias gladius, and blue shark, Prionace glauca), and some bycatch species (loggerhead sea turtles, Caretta caretta, and shortfin mako, Isurus oxyrinchus) caught by the Azorean longline fishing fleet. The trial was conducted for five consecutive years (2000-2004) using eight different types of hooks. In general, the blue shark catches using circle hooks were significantly higher compared to J (Mustad 9/0). The circle hooks also showed high probabilities of catching juvenile blue sharks. Conversely, the circle hooks were efficient in reducing the loggerhead sea turtle bycatch and were related to fewer catches of small sea turtle individuals. The use of circle hooks was also associated with reduced swordfish catches compared to J (Mustad 9/0), and the effect of hook types on length at capture was only significant for Circle (L. & P. 18/0-CLP18) and Ringed Tuna (RT). No significant differences were observed comparing hook type to either catch rates or size selectivity for shortfin mako. Additionally, circle hooks were more likely to lodge in the mouth than in deeper anatomical positions, when compared to J (Mustad 9/0), for the four species analysed. The present study demonstrated that the use of circle hooks could mitigate the impact of the pelagic longline fisheries in the Azores by decreasing the bycatch of sea turtles and reducing animal injuries caused by deep hooking.

First assessment of circle hooks as bycatch mitigation measure for deep-water sharks on longline fisheries

The recognition that deep-water sharks are among the most vulnerable marine species to fisheries exploitation led to the implementation of fishing prohibition regulations in European waters. Reducing unwanted bycatch and mortality are key fisheries mitigation measure for the conservation of these species. Yet, few studies have investigated how to mitigate the common bycatch of these sharks on deep-water longline fisheries. Specifically, the potential of hook type as such a measure has never been investigated. Here, we conducted fishing experiments to test how circle hooks affect the catchability, the hooking position, and the overall condition of deep-water sharks, in comparison to the commonly used J-hooks in the Azores bottom longline fishery. We found that circle hooks did not significantly reduce deep hooking (throat or gut hooked), nor improve the overall condition of captured sharks, while the catchability of deep-water sharks on circle hooks was greater than on the J-hooks currently used in the local fishery. As such, circle hooks do not appear as a suitable measure to reduce deep-water shark bycatch and increase survival potential in deep-water longlining. Despite deep hooking being rare for the deep-water sharks caught with both hook types in the experiments, at-vessel mortality was still substantial (around 40%). Post-release survival remains mostly unquantified but preliminary results suggest it could also be high. This study highlights the urgent need for continued research addressing bycatch mitigation measures for deep-water sharks and identifying efficient strategies to reduce bycatch and increase survival.

Testing of hook sizes and appendages to reduce yelloweye rockfish bycatch in a Pacific halibut longline fishery

In Pacific halibut (Hippoglossus stenolepis) longline fisheries in the eastern North Pacific Ocean bycatch of yelloweye rockfish (Sebastes ruberrimus) is a concern as their stock status along the U.S. West Coast is “rebuilding” from being “overfished”, the southeast Alaska stock has shown a ∼60% decline since at least 1994 and through 2015 where it stabilized, and the Canadian stock has been recently declared “threatened”. In this study, we evaluated how size 16/0 and 18/0 circle hooks affect the catch efficiency of Pacific halibut and yelloweye rockfish. Further, we examined the catch efficiency of these hooks modified with a 3.1 mm stainless-steel wire appendage extending 7.6 cm from their shank at either a 45° or 90° angle. We estimated hooking location probabilities for Pacific halibut and yelloweye rockfish for the hooks tested, and tested for a difference in the time of capture between Pacific halibut and yelloweye rockfish. Results showed that hook size did not significantly affect the catch efficiency of Pacific halibut or yelloweye rockfish. However, hooks with a 45° appendage angle caught significantly fewer yelloweye rockfish than hooks without an appendage, irrespective of hook size. Appendage angle did not affect the catch efficiency of Pacific halibut. For both Pacific halibut and yelloweye rockfish, the most frequent hooking location was hook through cheek, both with and without an appendage. Time of capture of Pacific halibut and yelloweye rockfish did not differ over the duration of a set; however, the majority (75%) of individuals were caught within 2.5 h of gear deployment. Results from our study suggest that hook appendages could have potential use in reducing catch rates on yelloweye rockfish in Pacific halibut longline fisheries, which could lead to increased fishing opportunities, more efficient Pacific halibut fisheries and less effect of fluctuations in the more productive Pacific halibut stock on fisheries that may be constrained by yelloweye rockfish.

Fish Hooks and the Protection of Living Aquatic Resources in the Context of Recreational Catch-and-Release Fishing Practice and Fishing Tourism

The fish hook is a commonly known tool used in recreational fishing, which is one of the forms of active, specialised tourism. As a component of a fishing rod, the hook is intended to be anchored into the mouth of a fish and hold the fish on the end of the line while landing it. However, in the context of the protection of living aquatic resources and Catch-and-Release (C&R) fishing, its role and significance are becoming broader. In addition to the impact of the hook type on fishing efficiency, including the Catch Per Unit Effort (CPUE), the importance of hook selection in terms of minimising the resulting damage to the tissues of caught and released fish is increasing. It appears that alternative hook types, such as barbless hooks and circle hooks, are safer for fish in the aforementioned context while not significantly reducing fishing efficiency. This review study is aimed at describing the design, types, and role of the fish hook in modern C&R angling, including the impact of the hook type on both fishing efficiency and the safety and welfare of released fish, which translates into the status and protection of living aquatic resources. The issues presented in the study highlight a number of related technical, biological and social factors that are specific to inland angling in particular. Such a holistic perspective can be used to support the effective management of recreational fishing, which, as one of the most popular human activities when in contact with water, has a very significant impact on the state of the environment and, thus, on the possibility of tourism development.

Postrelease Mortality of Angled Tarpon in Puerto Rico

AbstractTarpon 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.

Mitigating effects on target and by-catch species fished by drifting longlines using circle hooks in the South Adriatic Sea (Central Mediterranean)

IntroductionLongline fishing gear has a higher by-catch rate than any other type of commercial fishing gear. Nowadays, there is an urgent need to find efficient management strategies to mitigate by-catch and the use of new hook types could be one of them. This study investigates the effects of a longline fishery (which targets swordfish, Xiphias gladius, in the South Adriatic Sea) replacing the traditional J-type hook with a circle hook (C-type hook) on target and by-catch species.MethodsFor this purpose, a fishing trip of nine days – with seven fishing sets – was monitored. For both targeted swordfish and by-catch specimens caught (i.e., blue shark, Prionace glauca; pelagic stingray, Pteroplatytrygon violacea; and loggerhead turtle, Caretta caretta), data about the hook type used (J-type vs. C-type), the specimen size, and their capture condition were collected.Results and discussionWith all species, we observed no significant difference in catch-per-unit-effort (CPUE) or specimen lengths between the two hook types. In addition, the hook type did not significantly affect the capture condition of swordfish, pelagic stingray, or loggerhead turtle specimens; however, it significantly affected the capture condition of blue sharks. The percentage of blue shark specimens found in healthy condition was higher when using a C-type hook (71.5%) than when using a J-type hook (22.6%). Overall, these preliminary results suggest that the use of a C-type hook improves the condition of by-caught blue sharks without affecting the CPUE or size of the target species. In conclusion, the use of a C-type hook could reduce the detrimental effects of by-catch on some species in the Adriatic Sea; however, this finding needs to be confirmed by a study with a larger sample size.

A Comparison of Circle and J Hook Performance Within the Grenadian Pelagic Longline Fishery

The use of circle hooks in pelagic longline fisheries has often been proposed as a minimally disruptive means to minimize bycatch mortality. However, most studies have been in large scale fisheries, not the small-vessel fleets seen in many Caribbean countries. Size 16/0 circle hooks and 9/0 J hooks were alternated over 26 sets to assess the performance of circle hooks in the Grenadian pelagic longline fishery. Catch, mortality, hook location, length, and grade of fish were compared between hook types. No species-specific differences in at-vessel mortality rate or yellowfin tuna grade were found between hook types. However, significantly fewer billfish collectively (t = 2.36, p = 0.028), and sailfish specifically (t = 3.04, p = 0.005), were caught on circle hooks. Additionally, tunas caught with circle hooks had a 69% greater chance of external hooking compared to J hooks (χ2 = 4.38, p = 0.036). All other species analyzed had similar catch rates regardless of hook type (p < 0.05), including yellowfin tuna. The results of this study suggest that the Grenadian pelagic longline fishery – and other Caribbean fleets, by extension – could reduce impacts on billfish stocks by using 16/0 circle hooks without incurring negative effects on yellowfin tuna catch rate or grade. With many bycatch species populations at depressed levels, these results also provide further evidence that circle hooks should be the recommended terminal gear type when using a bycatch mitigation approach to manage pelagic longline fisheries while maintaining target catches for local and export markets.

Analysis of At-Haulback Mortality and Influencing Factors of Indian Ocean Swordfish (Xiphias gladius)

The at-haulback mortality of swordfish (Xiphias gladius), a highly migratory fish, in the Indian Ocean during tuna longline fishery is a concern of the Indian Ocean Tuna Commission Fisheries Management. We obtained the data of 1144 swordfish recorded in 1925 operations in the Indian Ocean by Chinese tuna longline observers from 2012–2018. A generalized linear model was used to analyze the at-haulback mortality of swordfish and the potential influencing factors. The overall mortality rate of swordfish was 64.0%, and the average female size was 166.3 cm (SD = 32.5 cm), with an observed at-haulback mortality rate of 64.3%. The average male size was 155.1 cm (SD = 25.6 cm), which was smaller than females. The observed at-haulback mortality rate was 63.6%. No significant difference was observed between the sexes. Quarter, longitude, hook type, and Lower Jaw-Fork Length (LJFL) had a significant effect on the at-haulback condition when fish were retrieved onboard. Longitude and LJFL had a significant effect on the at-haulback mortality of swordfish. When the capture position was closer to the east, the at-haulback mortality decreased and LJFL increased. The interaction term of hook type and LJFL had a significant effect on at-haulback mortality. When using the circle hook and other hook types, the greater the LFJL, the greater the mortality rate; the opposite was true for Japanese tuna hooks. We provide information for understanding the at-haulback mortality of swordfish bycatch by Chinese tuna longline fishing fleets in the Indian Ocean and its influencing factors, which will help the future conservation and management of swordfish.

By-catch of sea turtles in Pacific artisanal fishery: Two points of view: From observer and fishers

Fisheries bycatch is a primary driver of population declines in marine megafauna. These captures not only have environmental impacts, they also have economic consequences for fishers such as direct losses when repairing fishing gear. Therefore, evaluating the fishers’ perception of bycatch and comparing it with data from scientific fisheries observers might provide a broader view of the current situation these species face. To do this, we obtained data concerning the bycatch of 1,838 sea turtles between 2008-2018 in the Eastern Pacific Ocean as well as informative surveys from 421 artisanal fishers surveyed in 2020. There is a discrepancy between the bycatch observed and the fishers’ perceptions of it. The observers’ results identified that high rates of incidental capture of sea turtles are associated with the mahi mahi fishery that occurs during winter and is a shallow set fishery using fish as bait. The olive ridley turtle was the main species affected by bycatch. According to the fishers’ perception, bycatch was higher with the use of J-hooks and a longline (compared to circle hooks and to gill nets and trawl nets) and when the target species are pelagic fish during the winter season. In addition, the fishers’ perception showed that 39.4% considered incidental fishing as an environmental problem and 28.5% considered it as a nuisance, while 32.1% do not consider sea turtle bycatch as a problem. These findings suggest that 60% of fishers do not consider it a need to protect sea turtles. Given the different responses between fisheries observers and fishers’ perception, it is clear that more dialogue is necessary to raise awareness about the effects of bycatch on worldwide sea turtle populations. Thus, there is an enormous potential to recruit/increase fishers’ active participation for turtle protection. In this context, the idea of including the fishers’ perception into any management strategy or conservation measure should be reinforced in order to effectively reduce the bycatch of these iconic species.

Influence of fish attractant on hooking location of Lutjanus carponotatus and Epinephelus quoyanus caught with soft plastic and hard‐bodied lures

AbstractRecreational fishing gear continues to evolve, and factors such as anatomical hooking location may change over time due to technology creep. We revisited studies conducted in 1996 by re‐examining hooking location in experiments where hard‐bodied and soft plastic lures were presented to stripey (Lutjanus carponotatus) and wire netting cod (Epinephelus quoyanus) either with or without application of a synthetic fish attractant. These data were compared to those of fish hooked on organic bait using circle or J‐style hooks. Lure type and application of attractant both significantly affected hooking location. Addition of attractant to hard‐bodied lures reduced foul hooking of both species. For L. carponotatus, soft plastic lures both with and without attractant tended to be taken deeper than hard‐bodied lures. For E. quoyanus captured on soft plastic lures coated with attractant, hooking locations were similar to those using organic baits on circle hooks. However, deepest hooking of both species occurred using organic bait on J‐style hooks. The use of soft plastic lures with an effective fish attractant may result in deeper hooking, which could potentially influence post‐release survival and increase fishing power.

Ghost Fishing by Abandoned Trotlines in a Simulated and Actual Reservoir

AbstractGhost fishing is described as the continuation of fishing by abandoned fishing gear. The freshwater trotline, a passive gear that is routinely found abandoned, has never been evaluated for its ability to ghost fish. We tested the effectiveness of top‐water set trotlines to ghost fish in (1) a simulated reservoir (i.e., hatchery ponds) and (2) an actual reservoir. In our simulated reservoir, we exposed Channel Catfish Ictalurus punctatus to baited and bare (unbaited) hooks of two hook styles (circle and “J”) during the winter and summer seasons. We found that in the simulated reservoir, catch rates of baited hooks (mean = 18.4 fish per 24 hooks, standard error [SE] = 2.13) did not differ significantly from bare hooks (mean = 15.3 fish per 24 hooks, SE = 1.77), circle hooks were 1.5 times more effective at catching fish than “J” hooks (χ2 = 4.19, df = 1, P = 0.041), and fish were retained longer in the winter (mean = 12.7 d, SE = 0.66) compared to the summer (mean = 2.8 d, SE = 0.21). We used the actual reservoir portion to examine the long‐term fishability and the overall longevity of the trotline gear during the same seasons. Catch was highest during the first week and decreased with time. Trotlines caught mostly fish (81.6%), and most catch (&gt;68%) occurred after the initial bait was lost. Winter‐set trotlines captured more organisms (11.6 per 25‐hook trotline; SE = 2.05) than summer‐set trotlines (5.2; SE = 0.99). Trotline longevity was assessed by counting the fishable hooks through time. Longevity differed between seasons (P = 0.0039), and winter‐set trotlines lasted longer (50% hook loss at 52 d, 95% confidence interval [CI] = [49, 77]) than summer‐set trotlines (32 d, 95% CI = [24, 36]). This study confirms that abandoned freshwater trotlines do ghost fish and will continue for months after they are initially set.

Effect of hook eye alignment on deep hooking rates for stream‐dwelling trout caught with baited circle and J hooks

It has been well documented that circle hooks generally reduce deep hooking of bait-caught fish. However, for decades there has been speculation that the hook eye must be straight relative to the shank for circle hooks to function properly, yet this aspect of hook configuration has rarely been investigated. Using a passive hook set when strikes were detected, we compared deep hooking rates and catch probability for stream-dwelling trout (Yellowstone cutthroat trout [Oncorhynchus clarkii bouvieri Jordan & Gilbert], rainbow trout [O. mykiss Walbaum], and cutthroat trout × rainbow trout hybrids) caught using baited circle and J hooks with the eye either straight with or turned-up from the shank. Landed fish averaged 26 cm in total length and ranged from 11 to 46 cm. Most fish (83%) were hooked either in the upper or lower jaw, but 16% were hooked deeply (i.e., either in the esophagus or the gills). As expected, the deep hooking rate was lower for circle hooks (10%) than for J hooks (24%). Logistic regression model results indicated that hook eye orientation had no effect on deep-hooking, with deep hooking rates of 11.0% and 8.2% for circle hooks with angled-up and straight eyes, respectively, compared to 21.7% and 25.3% for J hooks with angled-up and straight eyes. Model results also revealed that deep hooking probability differed among anglers but did not differ between species and was not related to fish length. Catch probability (i.e., the proportion of fish strikes that resulted in a landed fish) did not differ between hooks or hook eye orientations. Contrary to some perceptions, our results suggest that changing the angle of the hook eye does not affect deep hooking rates when anglers use baited circle hooks to land stream-dwelling trout.