Use Of Circle Hooks Research Articles

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.

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.

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.

Effect of hook type and hook setting method on deep‐hooking rates when bait fishing for trout in lentic waters

AbstractFishing with circle hooks along with prescribed hook‐setting methods can reduce deep‐hooking rates in some fisheries, but baited circle hooks have not been evaluated in stillwater trout fisheries. Deep‐hooking rates and catch probabilities were compared for cutthroat trout Oncorhynchus clarkii​ (Richardson), rainbow trout Oncorhyncus mykiss (Walbaum), cutthroat × rainbow trout hybrids, and brook trout Salvelinus fontinalis (MItchill) caught using three types of baited hooks (circle, intermediate circle and traditional J) and two hook‐setting methods (active and passive) in several lakes containing naturally reared trout. Hook type had a negligible effect on deep‐hooking rates, which averaged 20%. Actively setting the hook and fishing with a bobber both reduced deep‐hooking rates, regardless of hook type. Larger fish were deeply hooked more frequently regardless of hook type. Catch probabilities were higher when active rather than passive hook‐setting was used, particularly in combination with intermediate circle hooks. The present results, which indicate that circle hook use did not reduce deep hooking in lentic settings, contrast earlier studies done in lotic waters. Therefore, before proposing hook‐type regulations intended to reduce deep hooking, fisheries managers should consider waterbody type in addition to fishing methods, fish size and species.

Are circle hooks effective management measures in the pelagic longline fishery for sharks in the Gulf of Gabès?

Abstract This study evaluated the circle hook use as a tool for shark management in the pelagic longline fishery in the Gulf of Gabès. The usual J‐hook No. 2 with 10° offset, which has been traditionally used by the fishery, was compared to the 18/0 non‐offset circle hook in an alternating fashion along the main line. In total, 22 experimental longline sets were deployed through the shark fishing seasons of 2016 and 2017 to examine the effects of hook types on the catch composition, the catch rates, the hooking location, and the status at haulback. The catch composition differed significantly among hook types. Moreover, an overall increase in catch rates for the main species, the sandbar shark Carcharhinus plumbeus, and the shortfin mako shark Isurus oxyrinchus, was observed when using circle hooks. There was no size‐selective effect of circle hooks for the common species. The circle hooks were not effective at reducing at‐haulback mortality of sandbar shark. Conversely, shortfin mako and smooth‐hound shark Mustelus mustelus showed significantly lower relative mortality at haulback with circle hooks than with J‐hooks. Furthermore, circle hooks were more frequently hooked externally than the J‐hooks for the three shark species. Results demonstrated that the use of 18/0 non‐offset circle hooks in the pelagic shark longline fishery can reduce mortality at haulback for some species without any benefit for the dominant species, the sandbar shark. Overall, it is difficult to promote the adoption of the use of circle hooks as a management measure in this specialized fishery. Management measures focusing on fishing effort controls, fishing closures in critical habitats, and size limits could have significant benefits for the conservation of shark species and may help to improve the sustainability of the shark fishery in the Gulf of Gabès.

Circle hook versus J-hook: A case study of the Sultanate of Oman

This paper analyses the operational efficiency and economic performance of the circle hook and the J-hook, commonly used by traditional fishers in the demersal longline fishery of the Sultanate of Oman. A longline experiment was conducted at three fishing locations at Masirah Island of Al-Sharqiyah Governorate. A total of 6,120 baited J-hooks and circle hooks were deployed over a 17-day period. The findings from this experimental research suggest that the overall performance (measured under various operational yardsticks such as hooking status and location, catch composition and quality, catching efficiency, and time and cost efficiency) of the circle hook is better than its counterpart. The results also indicate that the use of circle hooks has the potential to yield better financial returns. It is acknowledged that the reliance on three fishing locations may restrict the scientific generalizations. However, it is hoped that the results from this study will provide insight into the design of future experiments to ensure the validity of the present results and make effective regulatory decisions.

Circle hook versus J-hook: A case study of the Sultanate of Oman

This paper analyses the operational efficiency and economic performance of the circle hook and the J-hook, commonly used by traditional fishers in the demersal longline fishery of the Sultanate of Oman. A longline experiment was conducted at three fishing locations at Masirah Island of Al-Sharqiyah Governorate. A total of 6,120 baited J-hooks and circle hooks were deployed over a 17-day period. The findings from this experimental research suggest that the overall performance (measured under various operational yardsticks such as hooking status and location, catch composition and quality, catching efficiency, and time and cost efficiency) of the circle hook is better than its counterpart. The results also indicate that the use of circle hooks has the potential to yield better financial returns. It is acknowledged that the reliance on three fishing locations may restrict the scientific generalizations. However, it is hoped that the results from this study will provide insight into the design of future experiments to ensure the validity of the present results and make effective regulatory decisions.

Catch rate and at‐vessel mortality of circle hooks versus J‐hooks in pelagic longline fisheries: A global meta‐analysis

AbstractWe conducted a meta‐analysis of literature reporting on the use of circle hooks and J‐hooks in pelagic longline fisheries. Our study included more data than previous meta‐analyses of the effects of hook type, due to both a larger number of relevant studies available in recent years and a more general modelling approach. Data from 42 empirical studies were analysed using a random effects model to compare the effects of circle hooks and J‐hooks on catch rate (43 species) and at‐vessel mortality (31 species) of target and bycatch species. Catch rates with circle hooks were greater for 11 species, including four tuna species, six shark species and one Istiophorid billfish. Catch rates on circle hooks were lower for seven species, including two Istiophorid billfishes and two species of sea turtle. At‐vessel mortality was significantly lower with circle hooks in 12 species, including three tuna species, three Istiophorid billfishes, swordfish (Xiphias gladius) and three shark species. No species had significantly greater at‐vessel mortality when captured with a circle hook rather than a J‐hook. While our general approach increased model variability compared to more detailed studies, results were consistent with trends identified in previous studies that compared the catch rates and at‐vessel mortality (between hook types) for a number of species. Our results suggest that circle hooks can be a promising tool to reduce mortality of some bycatch species in pelagic longline fisheries, although the effects depend on the species and the metric (catch rate or at‐vessel mortality), emphasizing the need for fishery‐specific data in conservation and management decisions.

Hook performance and selectivity of Eurasian perch, Perca fluviatilis (Linnaeus, 1758) in the Åland Archipelago, Finland

The effects of two hook-types (circle or J hook) fished with two different baits (red worms Eisenia spp., or cyprinid fishes) were examined for deep-hooking, catch rate, mean total length, and selectivity of Eurasian perch, Perca fluviatilis, in the Åland Archipelago, Finland. The perch population available to hook-and-line gear was sampled with multipanel gillnets, with panels ranging from 10 to 60 mm in stretched mesh diameter. The effect of each hook then was examined for each bait by conditioning the size distributions of hook-and-line catches on the size distribution of perch collected with gillnets to estimate selectivity. The proportion of deeply-hooked perch was 4.8 times greater for J hooks (0.21) than circle hooks (0.04) baited with worms and 3.7 times greater for J hooks (0.33) than circle hooks (0.09) baited with fish. Catch rates were significantly different between the two baits but not between the two hooks, with the greatest catch rate observed for the circle hook baited with worms. There was no significant difference in perch total length between the two hooks, but there was a significant difference between the two baits, with the fish bait catching significantly larger perch. Perch selection peaks between the two hooks differed by only 13.8 mm, but the selection peak with fish bait (236.4 mm TL) was 119.9 mm greater than the selection peak with the worm bait (116.5 mm TL). A substantially lesser incidence of deep hooking support the conservation benefits of circle hook use for perch, especially when catch-and-release is practiced. Using fish baits similar in size to those used in this experiment can avoid potentially harmful interactions between relatively small perch and anglers who place little importance on catch motives but whose satisfaction is still catch-dependent.

Assessing Fishers' Support of Striped Bass Management Strategies.

Incorporating the perspectives and insights of stakeholders is an essential component of ecosystem-based fisheries management, such that policy strategies should account for the diverse interests of various groups of anglers to enhance their efficacy. Here we assessed fishing stakeholders’ perceptions on the management of Atlantic striped bass (Morone saxatilis) and receptiveness to potential future regulations using an online survey of recreational and commercial fishers in Massachusetts and Connecticut (USA). Our results indicate that most fishers harbored adequate to positive perceptions of current striped bass management policies when asked to grade their state’s management regime. Yet, subtle differences in perceptions existed between recreational and commercial fishers, as well as across individuals with differing levels of fishing experience, resource dependency, and tournament participation. Recreational fishers in both states were generally supportive or neutral towards potential management actions including slot limits (71%) and mandated circle hooks to reduce mortality of released fish (74%), but less supportive of reduced recreational bag limits (51%). Although commercial anglers were typically less supportive of management changes than their recreational counterparts, the majority were still supportive of slot limits (54%) and mandated use of circle hooks (56%). Our study suggests that both recreational and commercial fishers are generally supportive of additional management strategies aimed at sustaining healthy striped bass populations and agree on a variety of strategies. However, both stakeholder groups were less supportive of harvest reductions, which is the most direct measure of reducing mortality available to fisheries managers. By revealing factors that influence stakeholders’ support or willingness to comply with management strategies, studies such as ours can help managers identify potential stakeholder support for or conflicts that may result from regulation changes.

Effects of hook and bait in a tropical northeast Atlantic pelagic longline fishery: Part II—Target, bycatch and discard fishes

The incidental bycatch of sea turtle in tuna and swordfish fisheries is currently recognized as one of the major threats to the populations of these species. Therefore a number of mitigation measures have been tested, particularly for longline fisheries targeting swordfish. As mitigation measures may also affect the fish catches, it is important to quantify these impacts both at the ecological and socio-economic levels. Between August 2008 and December 2011, a total of 202 experimental pelagic longline sets were carried out in the Tropical Northeast Atlantic Ocean. The combination J-hook baited with squid (traditionally used by the fishery) was compared against two circle hooks (one non-offset and one with 10° offset) and mackerel bait. Catches per unit effort (CPUE) were calculated and compared between the different hook style and bait combinations for all target, bycatch and discarded fish species. In addition, a GLM (generalized linear model) was applied for swordfish Xiphias gladius and blue shark Prionace glauca (two main target species) and bigeye thresher Alopias superciliosus (most discarded species). The swordfish catches were negatively affected when changing from the traditional gear (J-style hooks baited with squid) to one of the experimental combinations, with the bait type having a stronger influence than the hook style on this reduction. However, the overall target species CPUE and the value of the retained catch (VPUE, value per unit of effort) were not significantly affected, due to an increase on the blue shark CPUE. Furthermore, the hook style and the bait type did not seem to influence the at-haulback mortality rates of most discarded species, which were highly species-specific. Given the apparent lack of impact on the overall value of the retained catch, the use of circle hooks baited with mackerel on this particular fishery and region would be highly beneficial for sea turtle conservation, without affecting the economic viability of the fishery.

Effects of Appendaged Circle Hook Use on Catch Rates and Deep Hooking of Black Sea Bass in a Recreational Fishery

AbstractPrevious studies have demonstrated that circle hooks modified with an appendage can reduce the occurrence of deep hooking in some fishes. To determine whether this modification affects total catch and deep‐hooking rate of Black Sea Bass Centropristis striata in a recreational fishery off the coast of Florida, anglers were provided with standardized gear that included one appendaged and one nonappendaged hook. Both hook types were fished equally, and a greater number of Black Sea Bass were caught on appendaged hooks (n = 301) than on nonappendaged hooks (n = 221). There was no significant difference in the mean TL (P = 0.80) of jaw‐ or deep‐hooked fish during the study. Logistic regression was applied to the data using anatomical hooking location as the dependent variable and angler, hook position, and hook type as categorical factors. Hook type was the only significant variable in the final model (P = 0.03) in which fewer fish were deep hooked on appendaged hooks (0.96%) than on nonappendaged hooks (2.11%). Our findings indicate appendaged hooks are capable of reducing deep hooking of Black Sea Bass without reducing catch rates or altering size composition of the catch.Received February 3, 2014; accepted August 14, 2014

Hooking Mortality and Landing Success Using Baited Circle Hooks Compared to Conventional Hook Types for Stream-Dwelling Trout

We estimated hooking and landing success and relative hooking mortality for stream-dwelling trout caught with baited circle and J hooks, J hook dry flies, and treble hook spinners (all hooks barbed). Trout were caught, individually marked, and released for 69 days. Deep-hooking rate was higher for trout captured with baited J hooks (21%) than for spinners (5%), baited circle hooks (4%), and dry flies (1%). Relative mortality rate was higher for trout captured with baited J hooks (25%) and spinners (29%) than for trout captured with baited circle hooks (7%) and dry flies (4%). Deep-hooking was two and six times higher for baited J hooks than baited circle hooks for fish caught actively and passively , respectively. For baited circle hooks, deep-hooking was over three times greater when using an active fishing method (i.e., an active hookset) compared to passive fishing method (no hookset), which conflicts with manufacturer&s recommendations on how circle hooks should be fished. Hooking success (ratio of hook-ups to number of fish strikes) was about one-third lower for baited circle hooks fished both passively and actively compared to other hook types and fishing methods, except for passively-fished baited J hooks. Once hooked, landing success (ratio of fish landed to number of hook-ups) was relatively high for all hook types and fishing methods (range 68–87%). Our results suggest that when bait fishing for trout in streams, circle hook use may reduce deep-hooking and hooking mortality (but also catch rate) regardless of whether anglers fish passively or actively.

Short-term survival of discarded pearl perch (Glaucosoma scapulare Ramsay, 1881) caught by hook-and-line in Queensland, Australia

Post-release survival of line-caught pearl perch (Glaucosoma scapulare) was assessed via field experiments where fish were angled using methods similar to those used by commercial, recreational and charter fishers. One hundred and eighty-three individuals were caught during four experiments, of which >91% survived up to three days post-capture. Hook location was found to be the best predictor of survival, with the survival of throat- or stomach-hooked pearl perch significantly (P<0.05) lower than those hooked in either the mouth or lip. Post-release survival was similar for both legal (≥35cm) and sub-legal (<35cm) pearl perch, while those individuals showing no signs of barotrauma were more likely to survive in the short term. Examination of the swim bladders in the laboratory, combined with observations in the field, revealed that swim bladders rupture during ascent from depth allowing swim bladder gases to escape into the gut cavity. As angled fish approach the surface, the alimentary tract ruptures near the anus allowing swim bladder gases to escape the gut cavity. As a result, very few pearl perch exhibit barotrauma symptoms and no barotrauma mitigation strategies were recommended. The results of this study show that pearl perch are relatively resilient to catch-and-release suggesting that post-release mortality would not contribute significantly to total fishing mortality. We recommend the use of circle hooks, fished actively on tight lines, combined with minimal handling in order to maximise the post-release survival of pearl perch.

Incorporating Circle Hooks Into Atlantic Pelagic Fisheries: Case Studies from the Commercial Tuna/Swordfish Longline and Recreational Billfish Fisheries

An emerging body of literature has demonstrated the benefits of the use of circle hooks relative to standard J-hooks in commercial and recreational fisheries. In the pelagic longline fishery for tunas (Thunnus spp.) and swordfish (Xiphias gladius Linnaeus, 1758), the use of circle hooks has resulted in greater catch rates of some target species, lower catch rates of some bycatch species, and a higher percentage of many target and bycatch species alive at the time of haulback (gear retrieval). However, a lack of agreement among results of studies conducted in different fisheries and areas, using different baits and rigging techniques, and with different styles and sizes of circle hooks has hindered the adoption of this terminal tackle as a management measure at the international level. Nevertheless, some countries have mandated the use of circle hooks in pelagic longline fisheries to protect bycatch species, and some individual fishers have incorporated circle hooks because they appear to maximize individual profit. In the recreational fishery for billfishes (family Istiophoridae), which is primarily a catch-and-release fishery in the United States, studies have demonstrated that circle hooks result in higher rates of external hooking and post-release survival than standard J-hooks. The use of circle hooks in billfish fisheries has been promoted by the sportfishing industry and is currently required by some nations; however, partnerships promoting active outreach and education with stakeholders in both commercial and recreational fisheries are critical to maximize the use and conservation benefit of this technology.

An Overview of Circle Hook Use and Management Measures in United States Marine Fisheries

We provide an overview of the use of, and management measures for, circle hooks in various marine fisheries of the United states. Circle hooks have long been known for their conservation benefits, such as reducing deep hooking, and therefore, reducing post-release mortality associated with this event. Some Us commercial pelagic longline vessels voluntarily started using circle hooks due to increased catch rates for some target species and increased post-release survival of non-target species, whereas recreational anglers began using circle hooks to reduce post-release mortality in catch-and-release fisheries. Despite previous voluntary circle hook use, circle hooks have been a relatively new fishery management tool in Us state and federal fisheries. However, the difference in jurisdiction between state and federal waters has resulted in some disparity in state and federal circle hook regulations. In general, consistent management regulations between state and federal waters should be more beneficial for fish stocks that have both state and federal fisheries. Finally, while state and federal circle hook regulations are documented, voluntary circle hook use by commercial and recreational fishers participating in different state and federal fisheries is more difficult to characterize. Thus, overall circle hook use is difficult to quantify.

Circle Hooks in Commercial, Recreational, and Artisanal Fisheries: Research Status and Needs for Improved Conservation and Management

The intent of convening the international symposium on circle hooks in research, management, and conservation was to yield a contemporary, science-based assessment of the management and conservation utility of circle hooks in commercial, recreational, and artisanal fisheries around the globe. The symposium objective was to provide a forum for individuals, organizations, and agencies to share relevant research results and perspectives. Based on the presentations, an examination of the literature, and the collective experience and knowledge of the authors, we provide a brief overview of the current status of circle hook research along with a list of research needs, with a particular focus on science that has the potential to inform managers and stakeholders. progress was made on the definition of a true circle hook. There was strong recognition that circle hooks represent just one of the tools available to managers for reducing bycatch and release mortality. also defined was the need for an integrative approach that considers strategies that complement the use of circle hooks. some of the research needs identified include a greater emphasis on human dimension studies to identify those factors that may impede adoption of circle hook technology by stakeholders and comparative studies of circle hook performance relative to mouth morphology, dentition, and feeding behavior. While the literature on effective use of circle hooks is growing, there remains a number of unanswered questions that will require study before circle hooks are more widely adopted for conservation and management of aquatic living resources.

Hook Effects on Seabird Bycatch in the United States Atlantic Pelagic Longline Fishery

Recent studies suggest that use of circle hooks can reduce the incidental mortality of some marine fishes and sea turtles in longline fisheries. Analysis of data from the Us national Marine fisheries service pelagic observer program (pop) revealed a significant hook effect on seabird bycatch. Our analysis focused on the three areas with highest seabird bycatch, the northeast Us coast (60°W-71°W, 35°n-42°n), the Middle atlantic bight (71°W-82°W, 35°n-41°n), and the south atlantic bight (71°W-82°W, 30°n-35°n). We developed two generalized linear models to examine effects of four hook treatments, i.e., four combinations of hook type and size (8/0 J-hook, 9/0 J-hook, 16/0 circle hook, and 18/0 circle hook), on: (1) the probability of catching seabirds on a set and (2) the positive catch rate (i.e., number of seabirds per 1000 hooks in longline sets with at least one seabird caught). Results indicated that combinations of hook type and size significantly influenced the probability of catching seabirds in the United states atlantic pelagic longline fishery. Use of the 8/0 J-hook led to the highest probability of catching a seabird. Use of circle hooks may significantly reduce seabird bycatch in the Us atlantic pelagic longline fishery, but its effectiveness may be confounded by other factors such as bait type, fishing location, season, and target species. Results of our study were limited by the small number of seabird captures in the pop data.

The Effect of Circle Hooks on Shark Catchability and At-Vessel Mortality Rates in Longlines Fisheries

Circle hooks have gained recent attention as a cost-effective bycatch mitigation tool in pelagic longline fisheries, particularly for marine turtles. Over the last few years, a growing number of studies have investigated the use of circle hooks and their effects on other species, including elasmobranchs. To elucidate the potential value of circle hook use as a tool for shark conservation and management in pelagic longline fisheries, we conducted a quantitative review of all available studies to date. We compiled 15 published and eight gray literature studies and where possible used random effects meta-analysis and analysis of covariance to test the effects of circle hooks on catchability and at-vessel mortality rates. Overall, results suggest that using circle hooks on pelagic longlines do not have a major effect on shark catch rates, but do reduce at-vessel mortality compared to J-hooks. Thus circle hooks should be seen as one potential tool to help reduce bycatch mortality of sharks in longline fisheries. However, the high level of heterogeneity found between studies highlights the need for shark-specific controlled experiments to provide more definitive results.

Survival of Red Grouper (&lt;I&gt;Epinephalus Morio&lt;/I&gt;) and Red Snapper (&lt;I&gt;Lutjanus Campechanus&lt;/I&gt;) Caught on J-Hooks and Circle Hooks in the Florida Recreational and Recreational-for-Hire Fisheries

We documented survival of released sublegal red grouper, Epinephalus morio (valenciennes, 1828), and red snapper, lutjanus campechanus (poey, 1868), caught on circle and j-hooks by recreational anglers in florida waters. Immediate hook mortality was 20.0% for red grouper and 49.1% for red snapper. Delayed (5 d) hook mortality from blood loss of j-hook nicked internal organs differed between red grouper (7%) and red snapper (29%). Delayed mortality from starvation was observed for five emaciated red snapper with severed esophagi from prior hook injuries. Different survival rates were correlated with feeding behavior, jaw morphology, and prey residence time. Mean (±Sd) prey residence time in the mouth was significantly longer for red grouper (6.62 ± 0.42 s) than red snapper (3.73 ± 0.29 s) possibly resulting in more red grouper being mouth hooked than red snapper, which were more likely to swallow bait and become gut hooked. Jaw morphology and feeding behavior may predict release survival for other species. Tag recapture rates used as a surrogate for survival were significantly higher for tagged red grouper initially caught on circle hooks (14.0%, n = 121 recaptures; 863 tagged) than on j-hooks (7.3%, n = 287 recaptures; 3935 tagged). Conversely, recapture rates were significantly higher for red snapper initially caught on j-hooks (12.5%, n = 269 recaptures; 2145 tagged) than circle hooks (8.1%, n = 258 recaptures; 3172 tagged). Mandatory regulations implementing the use of circle hooks when targeting all reef fish species may not provide the intended conservation benefits.