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Clarke TM, Barnett A, Fitzpatrick R, Ryan LA, Hart NS, Gauthier ARG, Scott-Holland TB, Huveneers C. Personal electric deterrents can reduce shark bites from the three species responsible for the most fatal interactions. Sci Rep 2024; 14:16307. [PMID: 39009626 PMCID: PMC11251019 DOI: 10.1038/s41598-024-66679-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 07/03/2024] [Indexed: 07/17/2024] Open
Abstract
The frequency of unprovoked shark bites is increasing worldwide, leading to a growing pressure for mitigation measures to reduce shark-bite risk while maintaining conservation objectives. Personal shark deterrents are a promising and non-lethal strategy that can protect ocean users, but few have been independently and scientifically tested. In Australia, bull (Carcharhinus leucas), tiger (Galeocerdo cuvier), and white sharks (Carcharodon carcharias) are responsible for the highest number of bites and fatalities. We tested the effects of two electric deterrents (Ocean Guardian's Freedom+ Surf and Freedom7) on the behaviour of these three species. The surf product reduced the probability of bites by 54% across all three species. The diving product had a similar effect on tiger shark bites (69% reduction) but did not reduce the frequency of bites from white sharks (1% increase), likely because the electrodes were placed further away from the bait. Electric deterrents also increased the time for bites to occur, and frequency of reactions and passes for all species tested. Our findings reveal that both Freedom+ Surf and Freedom7 electric deterrents affect shark behaviour and can reduce shark-bite risk for water users, but neither product eliminated the risk of shark bites entirely. The increasing number of studies showing the ability of personal electric deterrents to reduce shark-bite risk highlights personal protection as an effective and important part of the toolbox of shark-bite mitigation measures.
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Affiliation(s)
- Thomas M Clarke
- Southern Shark Ecology Group, College of Science and Engineering, Flinders University, Adelaide, SA, 5042, Australia.
| | - Adam Barnett
- Marine Data Technology Hub, James Cook University, Townsville, QLD, Australia
- Biopixel Oceans Foundation, Cairns, QLD, Australia
| | | | - Laura A Ryan
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Nathan S Hart
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Arnault R G Gauthier
- Centre Sécurité Requin, 25F Avenue Des Artisans, Zone Artisanale de La Pointe Des Châteaux, 97436, Saint Leu, Reunion Island, France
| | | | - Charlie Huveneers
- Southern Shark Ecology Group, College of Science and Engineering, Flinders University, Adelaide, SA, 5042, Australia
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SMART Drumlines Ineffective in Catching White Sharks in the High Energy Capes Region of Western Australia: Acoustic Detections Confirm That Sharks Are Not Always Amenable to Capture. BIOLOGY 2022; 11:biology11101537. [PMID: 36290440 PMCID: PMC9598327 DOI: 10.3390/biology11101537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/11/2022] [Accepted: 10/14/2022] [Indexed: 11/17/2022]
Abstract
The management of human-shark interactions can benefit from the implementation of effective shark hazard mitigation measures. A Shark-Management-Alert-in-Real-Time (SMART) drumline trial in the Capes region of Western Australia was instigated after several serious incidents involving surfers and white sharks (Carcharodon carcharias). The project aimed to determine whether white sharks (target species), which were relocated after capture, remained offshore using satellite and acoustic tagging. Over a 27-month period, 352 fish were caught, 55% of which comprised tiger sharks (Galeocerdo cuvier). Ninety-one percent of animals were released alive in good condition. Only two white sharks were caught; both were relocated ≥ 1 km offshore before release and moved immediately further offshore after capture, remaining predominately in offshore waters for the duration of their 54-day and 186-day tag deployments. Our results confirm that desirable animal welfare outcomes can be achieved using SMART drumlines when response times are minimised. The low target catches and the detection of 24 other tagged white sharks within the study area supported the decision to cease the trial. Our results reiterate there is no simple remedy for dealing with the complexities of shark hazards and reinforce the importance of trialing mitigation measures under local conditions.
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Increased shark bite survivability revealed by two centuries of Australian records. Sci Rep 2022; 12:14121. [PMID: 35986014 PMCID: PMC9391475 DOI: 10.1038/s41598-022-16950-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 07/19/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractThe perceived and real threat of shark bites have significant direct health and indirect economic impacts. Here we assess the changing odds of surviving an unprovoked shark bite using 200 years of Australian records. Bite survivability rates for bull (Carcharhinus leucas), tiger (Galeocerdo cuvier) and white (Carcharodon carcharias) sharks were assessed relative to environmental and anthropogenic factors. Survivability of unprovoked bull, tiger and white shark bites were 62, 75 and 53% respectively. Bull shark survivability increased over time between 1807 and 2018. Survivability decreased for both tiger and white sharks when the person was doing an in water activity, such as swimming or diving. Not unsurprisingly, a watercraft for protection/floatation increased survivability to 92% from 30%, and 88% from 45%, for tiger and white sharks respectively. We speculate that survival may be related to time between injury and treatment, indicating the importance of rapid and appropriate medical care. Understanding the predictors of unprovoked bites, as well as survivability (year and water activity), may be useful for developing strategies that reduce the number of serious or fatal human-shark interactions without impacting sharks and other marine wildlife.
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Fish R, Chan KMA, Maller C, Hails RS, Aimé E, Gaston KJ. People and nature: The emerging signature of a relational journal. PEOPLE AND NATURE 2022. [DOI: 10.1002/pan3.10339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Robert Fish
- School of Anthropology and Conservation University of Kent Kent UK
| | - Kai M. A. Chan
- Institute for Resources, Environment and Sustainability University of British Columbia Vancouver British Columbia Canada
| | - Cecily Maller
- Centre for Urban Research RMIT University Melbourne Victoria Australia
| | | | | | - Kevin J. Gaston
- Environment and Sustainability Institute University of Exeter Exeter UK
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Bradshaw CJA, Meagher P, Thiele MJ, Harcourt RG, Huveneers C. Predicting potential future reduction in shark bites on people. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201197. [PMID: 34035935 PMCID: PMC8101541 DOI: 10.1098/rsos.201197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Despite the low chance of a person being bitten by a shark, there are serious associated costs. Electronic deterrents are currently the only types of personal deterrent with empirical evidence of a substantial reduction in the probability of being bitten by a shark. We aimed to predict the number of people who could potentially avoid being bitten by sharks in Australia if they wear personal electronic deterrents. We used the Australian Shark Attack File from 1900 to 2020 to develop sinusoidal time-series models of per capita incidents, and then stochastically projected these to 2066. We predicted that up to 1063 people (range: 185-2118) could potentially avoid being bitten across Australia by 2066 if all people used the devices. Avoiding death and injury of people over the next half-century is of course highly desirable, especially when considering the additional costs associated with the loss of recreational, commercial and tourism revenue potentially in the tens to hundreds of millions of dollars following clusters of shark-bite events.
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Affiliation(s)
- Corey J. A. Bradshaw
- Global Ecology, College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
| | - Phoebe Meagher
- Taronga Conservation Society Australia, Taronga Zoo, Sydney, New South Wales, Australia
| | - Madeline J. Thiele
- Global Ecology, College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
- Southern Shark Ecology Group, College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
| | - Robert G. Harcourt
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Charlie Huveneers
- Southern Shark Ecology Group, College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
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Adams KR, Gibbs L, Knott NA, Broad A, Hing M, Taylor MD, Davis AR. Coexisting with sharks: a novel, socially acceptable and non-lethal shark mitigation approach. Sci Rep 2020; 10:17497. [PMID: 33060667 PMCID: PMC7562904 DOI: 10.1038/s41598-020-74270-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/24/2020] [Indexed: 11/22/2022] Open
Abstract
Conflict between humans and large predators is a longstanding challenge that can present negative consequences for humans and wildlife. Sharks have a global distribution and are considered to pose a potential threat to humans; concurrently many shark species are themselves threatened. Developing strategies for coexistence between humans and this keystone group is imperative. We assess blimp surveillance as a technique to simply and effectively reduce shark encounters at ocean beaches and determine the social acceptance of this technique as compared to an established mitigation strategy—shark meshing. We demonstrate the suitability of blimps for risk mitigation, with detection probabilities of shark analogues by professional lifeguards of 0.93 in ideal swimming conditions. Social surveys indicate strong social acceptance of blimps and preference for non-lethal shark mitigation. We show that continuous aerial surveillance can provide a measurable reduction in risk from sharks, improving beach safety and facilitating coexistence between people and wildlife.
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Affiliation(s)
- Kye R Adams
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia.
| | - Leah Gibbs
- School of Geography and Sustainable Communities, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Nathan A Knott
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Allison Broad
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Martin Hing
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Matthew D Taylor
- School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia
| | - Andrew R Davis
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia
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