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Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas
Although relatively rare, human-shark interactions and sharks bites are increasing globally, which has led to the development of various mitigation measures. Electric shark deterrents (ESDs) have, so far, been the most effective personal deterrents, but have only been scientifically tested on one of...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Nature Publishing Group UK
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578011/ https://www.ncbi.nlm.nih.gov/pubmed/33087793 http://dx.doi.org/10.1038/s41598-020-74799-y |
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author | Gauthier, A. R. G. Chateauminois, E. Hoarau, M. G. Gadenne, J. Hoarau, E. Jaquemet, S. Whitmarsh, S. K. Huveneers, C. |
author_facet | Gauthier, A. R. G. Chateauminois, E. Hoarau, M. G. Gadenne, J. Hoarau, E. Jaquemet, S. Whitmarsh, S. K. Huveneers, C. |
author_sort | Gauthier, A. R. G. |
collection | PubMed |
description | Although relatively rare, human-shark interactions and sharks bites are increasing globally, which has led to the development of various mitigation measures. Electric shark deterrents (ESDs) have, so far, been the most effective personal deterrents, but have only been scientifically tested on one of the species most frequently responsible for shark bites, i.e. white shark (Carcharodon carcharias). We tested the effectiveness of five ESDs (E-Shark Force, NoShark, Rpela v2, Freedom + Surf, Freedom + Surf—Shortboard) on bull sharks, Carcharhinus leucas, over a period of 21 days in September 2019, in New Caledonia. Standardised bait was attached 30 cm below an experimental board that had an active ESD for up to 15 min, or until a bull shark touched the bait or the board. We compared the numbers of baits taken, numbers of passes and reactions around the board, as well as the distance between the sharks and the board among ESDs and against a control board with bait and no active ESD. The Freedom + Surf was the most effective ESD, reducing the amounts of baits taken by 42.3%, while the Rpela v2 and Freedom + Surf—Shortboard also significantly reduced the number of baits taken by 16.5% and 16.2% respectively. Mean distance between sharks and the bait was not affected by the ESDs, but the number of approaches and the proportion of reactions were both significantly higher when the Freedom + Surf was active compared to other ESDs. The effectiveness of all ESDs decreased over time, with the likelihood of the bait being taken increasing and the number of approaches and distance between sharks and the bait decreasing. Our findings show that the ability of ESDs to deter bull shark varies between products, with the Freedom + Surf resulting in the most behavioural changes, followed by the Rpela v2 and Freedom + Surf—Shortboard. However, none of the products tested completely stopped sharks from taking the bait. |
format | Online Article Text |
id | pubmed-7578011 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-75780112020-10-23 Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas Gauthier, A. R. G. Chateauminois, E. Hoarau, M. G. Gadenne, J. Hoarau, E. Jaquemet, S. Whitmarsh, S. K. Huveneers, C. Sci Rep Article Although relatively rare, human-shark interactions and sharks bites are increasing globally, which has led to the development of various mitigation measures. Electric shark deterrents (ESDs) have, so far, been the most effective personal deterrents, but have only been scientifically tested on one of the species most frequently responsible for shark bites, i.e. white shark (Carcharodon carcharias). We tested the effectiveness of five ESDs (E-Shark Force, NoShark, Rpela v2, Freedom + Surf, Freedom + Surf—Shortboard) on bull sharks, Carcharhinus leucas, over a period of 21 days in September 2019, in New Caledonia. Standardised bait was attached 30 cm below an experimental board that had an active ESD for up to 15 min, or until a bull shark touched the bait or the board. We compared the numbers of baits taken, numbers of passes and reactions around the board, as well as the distance between the sharks and the board among ESDs and against a control board with bait and no active ESD. The Freedom + Surf was the most effective ESD, reducing the amounts of baits taken by 42.3%, while the Rpela v2 and Freedom + Surf—Shortboard also significantly reduced the number of baits taken by 16.5% and 16.2% respectively. Mean distance between sharks and the bait was not affected by the ESDs, but the number of approaches and the proportion of reactions were both significantly higher when the Freedom + Surf was active compared to other ESDs. The effectiveness of all ESDs decreased over time, with the likelihood of the bait being taken increasing and the number of approaches and distance between sharks and the bait decreasing. Our findings show that the ability of ESDs to deter bull shark varies between products, with the Freedom + Surf resulting in the most behavioural changes, followed by the Rpela v2 and Freedom + Surf—Shortboard. However, none of the products tested completely stopped sharks from taking the bait. Nature Publishing Group UK 2020-10-21 /pmc/articles/PMC7578011/ /pubmed/33087793 http://dx.doi.org/10.1038/s41598-020-74799-y Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Gauthier, A. R. G. Chateauminois, E. Hoarau, M. G. Gadenne, J. Hoarau, E. Jaquemet, S. Whitmarsh, S. K. Huveneers, C. Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas |
title | Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas |
title_full | Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas |
title_fullStr | Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas |
title_full_unstemmed | Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas |
title_short | Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas |
title_sort | variable response to electric shark deterrents in bull sharks, carcharhinus leucas |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578011/ https://www.ncbi.nlm.nih.gov/pubmed/33087793 http://dx.doi.org/10.1038/s41598-020-74799-y |
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