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Shark Chaser, the original U.S. Navy chemical ‘shark repellent’, was primarily a package of copper acetate and nigrosine dye issued to all naval personnel but later proven to be inef- fective against repelling sharks. Scale bar = 5 cm. 

Shark Chaser, the original U.S. Navy chemical ‘shark repellent’, was primarily a package of copper acetate and nigrosine dye issued to all naval personnel but later proven to be inef- fective against repelling sharks. Scale bar = 5 cm. 

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Article
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The development of Shark Chaser by the U.S. Navy during World War II was the first serious effort to develop a chemical shark repellent. In the decade following the war reports of Shark Chaser ineffectiveness led the Office of Naval Research to search for a more efficacious shark repellent. After years without success, ONR eventually canceled the u...

Citations

... Chemical signals have been reported to be major sensory modalities at different various stages of their life cycle (Johnsen, 1986;Rigg et al., 2009). As sharks are considered a threat to humans, there has been a particular interest to study their biology and sensory physiology since the 1950s to discover efficacious shark repellents (Gilbert & Springer, 1963;Springer, 1955;Tuve, 1963) but none of the chemical substances tested were found to produce a quick and effective repellent response in the field (Sisneros & Nelson, 2001). After 70 years of research on shark repellents, no effective solution to reduce shark bycatch and depredation in commercial fisheries has been developed (Hart & Collin, 2015). ...
Article
For many years, tremendous effort has been dedicated to developing new industrial tuna fisheries, while their adverse impacts on threatened marine species have received relatively little attention. In tuna fisheries, bycatch is the major anthropogenic threat to marine megafauna in general, particularly sharks. Research on the development of gear technology for bycatch reduction and potential mitigation measures helped tuna Regional Fisheries Management Organizations adopt bycatch reduction management measures. After reviewing past research on the development of mitigation measures for pelagic longline and tropical purse seine fisheries based on pelagic species' behaviours, we describe promising new approaches integrating recent technological breakthroughs. New innovations include autonomous underwater vehicles carrying cameras along with miniaturized sensors, aerial drones, computer simulation of fishing gear geometry, environmental DNA assays, computer visualizations and deep learning. The successful application of such tools and methods promises to improve our understanding of factors that influence capture, escape and stress of caught species. Moreover, results emerging from recent ethological research explaining the power of social connection and learning in the “fish world” such as social learning from congeners, habituation to deterrents, and how past fishery interactions affect responses to fishing gear should be taken into account when developing technical mitigation measures.
... Nevertheless, despite historical anecdotal suggestions of semiochemical repellent utility (including reports from fishers about rotting shark tissue repelling other sharks from fishing gear) less attention has been directed towards empirical studies (Gilman et al., 2007;Hart and Collin, 2015). It is also clear that among the few relevant studies, and like for electrosensory repellents, there exists species-specific variability in responses, which supports ongoing work (Sisneros and Nelson, 2001;Jordan et al., 2013;Stroud et al., 2014;Hart and Collin, 2015). ...
... This study contributes to the few manipulative attempts at quantifying the utility of semiochemicals for affecting shark behaviour (Springer, 1954;Tester, 1963;Stroud et al., 2014;Sisneros and Nelson, 2001). However, unlike the general consensus from this small area of research, the data support null effects (Tester, 1963), with variability in catches attributed to other Table 3 Summary of fixed factors and their significance in selected models explaining variability in the numbers of contacts with hooks and catches among longlines without (control) and with decomposing shark tissue (treatment) in canisters for key species/groups, and the proportions of bait remaining and catches adjacent to a canister. ...
... This outcome could reflect known species-specific variability among responses to semiochemicals, although any discussion first requires consideration of the experimental constraints and limitations. O'Connell et al. (2014b) and Sisneros and Nelson (2001) indicted that only very small quantities of semiochemicals (e.g. including 50 × 10 −6 L near sharks in tonic immobility to ∼ 36 µg ml −1 or 36 parts per million) are necessary to elicit repellent responses in afflicted species, although the challenge remains to control dispersal from the source in a dynamic marine environment. ...
Article
The effects of decomposing shark tissue on catches of benthic longlines targeting various carcharhinids were assessed to inform possible use as a semiochemical shark deterrent. During 15 nights fishing, four benthic longlines (each comprising 18–30 hooks baited with mullet, Mugil cephalus) were deployed to 12–56 m overnight for 12–21 h off eastern Australia. Two of the longlines had 2.0–3.0 kg of decomposing shark tissue placed into porous cylindrical canisters (520 × 105 mm polyvinyl chloride) secured to the mainline mostly between every three hooks (15–20 m apart), while the other two longlines had empty canisters. In total, 150 fish were caught, comprising 14 species of elasmobranchs and especially tiger sharks, Galeocerdo cuvier (31% of total). The decomposing shark tissue in the canisters had no effects on catches of any species or groups, with variability among most attributed to fishing depth (positive relationship) and also soak time (negative) for carcharhinids and G. cuvier. Irrespective of the contents of the canisters and the lack of any semiochemical effects, there was some evidence of fewer sharks caught on adjacent hooks as moonlight increased, and possibly because of a visual response. There was no depredation of any decomposing shark tissue in the canisters, but three juvenile hooked sharks were substantially depredated, and presumably by larger individuals. Most (∼70%) of the remaining hooked sharks survived. While this study showed no repelling effects of decomposing shark tissue, the conclusions are restricted to the experimental conditions, including the source of tissue and the distance between hooks, which might be used as upper limit in any future work assessing for effects.
... There has been much research and focus on deterrents that an individual may use to deter a shark or reduce the risk of a bite occurring (Sisneros and Nelson, 2001;Smit and Peddemors, 2003;Stroud et al., 2014;Hart and Collin, 2015;Huveneers et al., 2018a and b;Egeberg et al., 2019;Thiele et al., 2020). However, for a management agency needing to enact public safety responses to the risk of unprovoked shark bite, the focus is not on approaches that an individual can use, but rather those that can be applied over a wide area (e.g. at a whole or a large section of beach). ...
... Surfactants such as sodium lauryl sulphate which is used in many common household goods (e.g. shampoos and laundry detergent) can elicit a response if delivered directly to the mouth of a shark (e.g. via a squirt gun), but is ineffective as a repellent when released at low concentrations (Smith, 1991;Sisneros and Nelson, 2001). A more recent focus on chemical deterrents has been for personal use rather than for broader deployment and based on biological compounds (semiochemicals) rather than those that are an irritant to shark senses (Hart and Collin, 2015). ...
Article
Responses to unprovoked shark bite involve public policies and management approaches that contend with the needs of public safety and the responsibility to protect threatened species. In Australia (Queensland and New South Wales) and South Africa, methods that aim to capture and kill large sharks adjacent to popular beaches are a long-standing approach aimed at reducing the risk of shark bite. This paper reviews non-lethal alternatives to catch and kill methods, and suggests optimal conditions for non-lethal systems that will assist policy makers and beach authorities in choosing public safety responses that can be applied at the ocean beach scale. Deployment needs to be strategic with sufficient knowledge of their likely effectiveness under local conditions. At this stage we believe there is no single approach universally applicable to ocean beaches where unprovoked shark bite occurs, although well considered and locally appropriate mitigation measures can reduce risk.
... A floating pilot in the sea may be in sharkinfested waters. Shark repellents to protect pilot are required to be incorporated in the ejection kit (Sisneros & Nelson, 2001). Flying clothing ensemble is a special unique combination of FR overall, Anti G suit, Automatic inflatable life jacket, leg garter, helmet, special boot gloves, etc. ...
Article
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Operation of Armed Forces personnel in harsh military terrains for extended tenure period necessitates protection from elements and battle hazards. Harsh military terrains exert profound effects on the physical and physiological performance of the soldiers and can impart serious health hazards on inadequately protected soldiers resulting in mission failure and avoidable loss of lives. Harsh military terrains can be Mountain environment characterized by treacherous terrains with extreme cold and hypoxia, Deserts characterized by extreme heat stress, Depths of underwater that can pose life threatening situation in case of a distressed submarine, Aviation hazards (such as deadly G-forces faced by fighter pilots during G-manoeuvres and fire hazards that may result from crash) etc. Clothing being the first layer of protection for the wearer, forms an important protective measure in military operation against combat and environmental hazards. A great deal of research is being carried out by military/defence research laboratories worldwide in collaboration with industries to develop technical textiles incorporating suitable smart material finishes for the alleviation of the dangers associated in the combat terrain. Extended Cold weather clothing ensemble, High Altitude Pulmonary Oedema chambers, Anti-G suits, Flame retardant overalls, Submarine Escape Sets, Chemical warfare protection ensemble, liquid cooled garment for protection against hyperthermia etc., are fabricated from variety of technical textiles having special material properties. Technical textiles are used worldwide to provide protection from the hazards of battlefield to the military and paramilitary forces, as ‘man behind the machine’ is the most important entity in a war theatre. This review focuses a collective account of harsh military environment faced by war fighters during War & Peacetime and material development to develop desired technical textiles to lower the attrition due to harsh environment and battle hazards.
... 129 Unfortunately, tests of the ability of pardaxin as a shark repellent in an open beach setting showed that it was too quickly diluted in open water to be effective. 130 ...
Article
Membrane permeabilizing peptides (MPPs) are as ubiquitous as the lipid bilayer membranes they act upon. Produced by all forms of life, most membrane permeabilizing peptides are used offensively or defensively against the membranes of other organisms. Just as nature has found many uses for them, translational scientists have worked for decades to design or optimize membrane permeabilizing peptides for applications in the laboratory and in the clinic ranging from antibacterial and antiviral therapy and prophylaxis to anticancer therapeutics and drug delivery. Here, we review the field of membrane permeabilizing peptides. We discuss the diversity of their sources and structures, the systems and methods used to measure their activities, and the behaviors that are observed. We discuss the fact that "mechanism" is not a discrete or a static entity for an MPP but rather the result of a heterogeneous and dynamic ensemble of structural states that vary in response to many different experimental conditions. This has led to an almost complete lack of discrete three-dimensional active structures among the thousands of known MPPs and a lack of useful or predictive sequence-structure-function relationship rules. Ultimately, we discuss how it may be more useful to think of membrane permeabilizing peptides mechanisms as broad regions of a mechanistic landscape rather than discrete molecular processes.
... However, there are few acoustic deterrents that have been found to be effective in deterring sharks and, at least for longline sets where sounds may be presented over long periods of time, these types of deterrents are likely to be unsuccessful in the long-term due to habituation (Myrberg et al. 1969. Chemical deterrents, such as 'paradaxin' derived from the moses sole (Pardachirus marmoratus, Soleidae), sodium lauryl sulphate and semiochemical compounds, have been effective at repelling sharks under certain circumstances (Smith 1991;Sisneros and Nelson 2001;Stroud et al. 2014). However, such compounds may be impractical for fisheries use, due to the potentially harmful effects they may have on target fish and non-target marine organisms, and because of rapid dilution in open water, especially in the presence of currents (Baldridge 1990). ...
Article
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Shark depredation, where a shark partially or completely consumes an animal caught by fishing gear before it can be retrieved to the fishing vessel, occurs in commercial and recreational fisheries worldwide, causing a range of negative biological and economic impacts. Despite this, it remains relatively understudied compared to other fisheries issues. This is the first review of the literature relating to shark depredation, which also includes an overview of the potential mechanisms underlying its occurrence and options for mitigation. Furthermore, this review highlights key research gaps that remain to be investigated, thereby providing impetus for future research. In total, 61 studies have been published between 1955 and 2018, which include information on shark depredation. These studies recorded quantitative rates of depredation between 0.9 and 26% in commercial and recreational fisheries and during research fishing, identified 27 shark species from seven families that were responsible for depredation and discussed potential factors influencing its occurrence. Information from research into bycatch mitigation and the testing of shark deterrent approaches and technologies is also presented, in the context of applying these approaches to the reduction of shark depredation. This review presents an holistic overview of shark depredation in fisheries globally and, in doing so, provides a central resource for fisheries researchers and managers focusing on this topic to stimulate further collaborative research on this important fisheries issue.
... For example, various aposematic colour configurations (i.e., use of colours as anti-predator tactics) have been alleged to repel sharks. Using chemicals as shark repellents has also been proposed (Baldridge, 1990;Rasmussen & Schmidt, 1992;Sisneros & Nelson, 2001). However, the sensitivity of the electro-receptive organ of sharks to strong electric fields and its potential ability to deter sharks have been studied the most (e.g., Huveneers et al., 2013b;O'Connell et al., 2014b). ...
Article
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The number of shark-human interactions and shark bites per capita has been increasing since the 1980s, leading to a rise in measures developed to mitigate the risk of shark bites. Yet many of the products commercially available for personal protection have not been scientifically tested, potentially providing an exaggerated sense of security to the people using them. We tested five personal shark deterrents developed for surfers ( Shark Shield Pty Ltd [ Ocean Guardian ] Freedom+ Surf, Rpela, SharkBanz bracelet, SharkBanz surf leash, and Chillax Wax ) by comparing the percentage of baits taken, distance to the bait, number of passes, and whether a shark reaction could be observed. We did a total of 297 successful trials at the Neptune Islands Group Marine Park in South Australia, during which 44 different white sharks ( Carcharodon carcharias ) interacted with the bait, making a total of 1413 passes. The effectiveness of the deterrents was variable, with the Freedom+ Surf affecting shark behaviour the most and reducing the percentage of bait taken from 96% (relative to the control board) to 40%. The mean distance of sharks to the board increased from 1.6 ± 0.1 m (control board) to 2.6 ± 0.1 m when the Freedom Surf+ was active. The other deterrents had limited or no measureable effect on white shark behavour. Based on our power analyses, the smallest effect size that could be reliably detected was ∼15%, which for the first time provides information about the effect size that a deterrent study like ours can reliably detect. Our study shows that deterrents based on similar principles—overwhelming a shark’s electroreceptors (the ampullae of Lorenzini) with electrical pulses—differ in their efficacy, reinforcing the need to test each product independently. Our results will allow private and government agencies and the public to make informed decisions about the use and suitability of these five products.
... Deep setting of the hooks, magnetic repellents, avoidance of peak areas and periods of shark abundance and hot spot avoidance through fleet communication are considered as efficient methods for reducing shark and cetacean bycatch (Francis et al., 2001;Gilman et al., 2006a;Gilman, 2008a, b). Shark repellent chemicals are found to be very effective in preventing the shark from taking the bait (Sisneros and Nelson, 2001). Future analyses of depredation based on a closer examination of the sitespecific environmental characteristics may help to minimize the depredation and improve the economic benefits to the fishermen. ...
Article
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This article reviews the importance of bait, bait loss, and depredation in longline fishery operations worldwide. In general, fish bait is preferred over squid due to reduced sea turtle and elasmobranch bycatch. However, there are many reports which have indicated high shark catch and deep hooking when using fish as bait. High and low hooking rates for blue shark have been reported from different fishing areas when using mackerel as bait, indicating the need for further studies on selection of appropriate baits. Conflicting results from many part of the world on the catching efficiency of different bait species on target and nontarget species indicate the need to consider area, species specific and cross taxa effect of various combinations of baits and hooks, before their adoption in commercial fishing. Baiting pattern has also been reported to affect the catch rates significantly. The review has revealed that bait loss and depredation on the hooked fish cause considerable damage to the fishery and significant economic loss. Loss rates can be significantly minimized using squids as bait while it may also incur a high catch rate of bycatch. The review has confirmed the superiority of natural baits over alternative and artificial baits during the longline fishing operations. Though an effective substitute for the natural bait has not been developed, so far, such alternatives which make use of the food and foraging behavior and the olfactory response of the fish are necessary for future development of longline fisheries.
... Sisneros and Nelson, 2001 ;Southwood et al., 2008 ;(Dagorn et al., 2010;Jordan et al., 2013;Sisneros and Nelson, 2001;Southwood et al., 2008;Stroud et al., 2014) (Hart and Collin, 2015) Auditory deterrents and attractors ...
... Sisneros and Nelson, 2001 ;Southwood et al., 2008 ;(Dagorn et al., 2010;Jordan et al., 2013;Sisneros and Nelson, 2001;Southwood et al., 2008;Stroud et al., 2014) (Hart and Collin, 2015) Auditory deterrents and attractors ...
Article
Tuna fisheries have been identified as one of the major threats to populations of other marine vertebrates, including sea turtles, sharks, seabirds and marine mammals. The development of technical mitigation measures (MM) in fisheries is part of the code of conduct for responsible fisheries. An in-depth analysis of the available literature regarding bycatch mitigation in tuna fisheries with special reference to elasmobranchs was undertaken. Studies highlighting promising MMs were reviewed for four tuna fisheries (longline, purse seine, driftnets and gillnet, and rod and line-including recreational fisheries). The advantages and disadvantages of different MMs are discussed and assessed based on current scientific knowledge. Current management measures for sharks and rays in tuna Regional Fishery Management Organizations (t-RFMOs) are presented. A review of relevant studies examining at-vessel and postrelease mortality of elasmobranch bycatch is provided. This review aims to help fisheries managers identify pragmatic solutions to reduce mortality on pelagic elasmobranchs (and other higher vertebrates) whilst minimizing impacts on catches of target tuna species. Recent research efforts have identified several effective MMs that, if endorsed by t-RFMOs, could reduce elasmobranchs mortality rate in international tropical purse seine tuna fisheries. In the case of longline fisheries, the number of operational effective MMs is very limited. Fisheries deploying driftnets in pelagic ecosystems are suspected to have a high elasmobranchs bycatch and their discard survival is uncertain, but no effective MMs have been field validated for these fisheries. The precautionary bans of such gear by the EU and by some t-RFMOs seem therefore appropriate. Recreational tuna fisheries should be accompanied by science-based support to reduce potential negative impacts on shark populations. Priorities for research and management are identified and discussed.
... 1977) are only useful as a directional repellent and need to be delivered directly in the presence of sharks (Smith, 1991;Sisneros & Nelson, 2001). Gear modifications, such as the use of circle hooks instead of the often used j-shaped hooks appear promising (Kaplan et al., 2007) but are not always successful (Read, 2007), and may even be harmful to other protected animals (Gilman et al., 2008). ...
Article
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This experimental study focused on the possible deterrent effect of permanent magnets on adult sandbar sharks Carcharhinus plumbeus. Results showed that the presence of a magnetic field significantly reduced the number of approaches of conditioned C. plumbeus towards a target indicating that adult C. plumbeus can be deterred by strong magnetic fields. These data, therefore, confirm that the use of magnetic devices to reduce shark by-catch is a promising avenue.