1
|
Huveneers C, Blount C, Bradshaw CJA, Butcher PA, Lincoln Smith MP, Macbeth WG, McPhee DP, Moltschaniwskyj N, Peddemors VM, Green M. Shifts in the incidence of shark bites and efficacy of beach-focussed mitigation in Australia. MARINE POLLUTION BULLETIN 2024; 198:115855. [PMID: 38043202 DOI: 10.1016/j.marpolbul.2023.115855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/21/2023] [Accepted: 11/24/2023] [Indexed: 12/05/2023]
Abstract
Shark-human interactions are some of the most pervasive human-wildlife conflicts, and their frequencies are increasing globally. New South Wales (Australia) was the first to implement a broad-scale program of shark-bite mitigation in 1937 using shark nets, which expanded in the late 2010s to include non-lethal measures. Using 196 unprovoked shark-human interactions recorded in New South Wales since 1900, we show that bites shifted from being predominantly on swimmers to 79 % on surfers by the 1980s and increased 2-4-fold. We could not detect differences in the interaction rate at netted versus non-netted beaches since the 2000s, partly because of low incidence and high variance. Although shark-human interactions continued to occur at beaches with tagged-shark listening stations, there were no interactions while SMART drumlines and/or drones were deployed. Our effect-size analyses show that a small increase in the difference between mitigated and non-mitigated beaches could indicate reductions in shark-human interactions. Area-based protection alone is insufficient to reduce shark-human interactions, so we propose a new, globally transferable approach to minimise risk of shark bite more effectively.
Collapse
Affiliation(s)
- Charlie Huveneers
- Southern Shark Ecology Group, College of Science and Engineering, Flinders University, Adelaide, South Australia 5001, Australia.
| | - Craig Blount
- Stantec Australia Pty Ltd., St Leonards, New South Wales 1590, Australia
| | - Corey J A Bradshaw
- Global Ecology | Partuyarta Ngadluku Wardli Kuu, College of Science and Engineering, Flinders University, Adelaide, South Australia 5001, Australia
| | - Paul A Butcher
- New South Wales Department of Primary Industries Fisheries, National Marine Science Centre, Coffs Harbour, New South Wales 2450, Australia; Southern Cross University, National Marine Science Centre, Coffs Harbour, New South Wales 2450, Australia
| | - Marcus P Lincoln Smith
- Stantec Australia Pty Ltd., St Leonards, New South Wales 1590, Australia; Faculty of Science and Engineering, Macquarie University, North Ryde, New South Wales 2109, Australia
| | - William G Macbeth
- Stantec Australia Pty Ltd., St Leonards, New South Wales 1590, Australia
| | - Daryl P McPhee
- Faculty of Society and Design, Bond University, Gold Coast, Queensland 4229, Australia
| | - Natalie Moltschaniwskyj
- New South Wales Department of Primary Industries Fisheries, Port Stephens Fisheries Institute, Nelson Bay, New South Wales 2315, Australia; School of Environmental Science, University of Newcastle, Newcastle, New South Wales 2308, Australia
| | - Victor M Peddemors
- New South Wales Department of Primary Industries Fisheries, Sydney Institute of Marine Science, Mosman, New South Wales 2088, Australia
| | - Marcel Green
- New South Wales Department of Primary Industries Fisheries, Sydney Institute of Marine Science, Mosman, New South Wales 2088, Australia
| |
Collapse
|
2
|
Mitchell JD, Drymon JM, Vardon J, Coulson PG, Simpfendorfer CA, Scyphers SB, Kajiura SM, Hoel K, Williams S, Ryan KL, Barnett A, Heupel MR, Chin A, Navarro M, Langlois T, Ajemian MJ, Gilman E, Prasky E, Jackson G. Shark depredation: future directions in research and management. REVIEWS IN FISH BIOLOGY AND FISHERIES 2023; 33:475-499. [PMID: 36404946 PMCID: PMC9664043 DOI: 10.1007/s11160-022-09732-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 09/28/2022] [Indexed: 05/19/2023]
Abstract
Shark depredation is a complex social-ecological issue that affects a range of fisheries worldwide. Increasing concern about the impacts of shark depredation, and how it intersects with the broader context of fisheries management, has driven recent research in this area, especially in Australia and the United States. This review synthesises these recent advances and provides strategic guidance for researchers aiming to characterise the occurrence of depredation, identify the shark species responsible, and test deterrent and management approaches to reduce its impacts. Specifically, the review covers the application of social science approaches, as well as advances in video camera and genetic methods for identifying depredating species. The practicalities and considerations for testing magnetic, electrical, and acoustic deterrent devices are discussed in light of recent research. Key concepts for the management of shark depredation are reviewed, with recommendations made to guide future research and policy development. Specific management responses to address shark depredation are lacking, and this review emphasizes that a "silver bullet" approach for mitigating depredation does not yet exist. Rather, future efforts to manage shark depredation must rely on a diverse range of integrated approaches involving those in the fishery (fishers, scientists and fishery managers), social scientists, educators, and other stakeholders.
Collapse
Affiliation(s)
- J. D. Mitchell
- Queensland Government, Department of Agriculture and Fisheries, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102 Australia
| | - J. M. Drymon
- Mississippi State University, Coastal Research and Extension Center, 1815 Popps Ferry Road, Biloxi, MS 39532 USA
- Mississippi-Alabama Sea Grant Consortium, 703 East Beach Drive, Ocean Springs, MS 39564 USA
| | - J. Vardon
- Southern Cross University, Lismore, NSW Australia
| | - P. G. Coulson
- Department of Primary Industries and Regional Development, Western Australian Fisheries and Marine Research Laboratories, 39 Northside Drive, Hillarys, WA 6025 Australia
| | - C. A. Simpfendorfer
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, TAS 7004 Australia
| | - S. B. Scyphers
- Coastal Sustainability Institute, Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA 01908 USA
- Social Science Environmental Health Research Institute, Northeastern University, Boston, MA 02115 USA
| | - S. M. Kajiura
- Department of Biological Sciences, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431 USA
| | - K. Hoel
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Bldg 34 James Cook Drive, Douglas, QLD 4811 Australia
| | - S. Williams
- Queensland Government, Department of Agriculture and Fisheries, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102 Australia
- School of Biological Sciences, The University of Queensland, St Lucia, Qld 4072 Australia
| | - K. L. Ryan
- Department of Primary Industries and Regional Development, Western Australian Fisheries and Marine Research Laboratories, 39 Northside Drive, Hillarys, WA 6025 Australia
| | - A. Barnett
- Biopixel Oceans Foundation, Cairns, QLD Australia
- Marine Data Technology Hub, James Cook University, Townsville, QLD 4811 Australia
| | - M. R. Heupel
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, TAS 7004 Australia
| | - A. Chin
- Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Bldg 34 James Cook Drive, Douglas, QLD 4811 Australia
| | - M. Navarro
- School of Biological Sciences, The University of Western Australia, Crawley, WA Australia
- The Oceans Institute, University of Western Australia, Crawley, WA Australia
| | - T. Langlois
- School of Biological Sciences, The University of Western Australia, Crawley, WA Australia
- The Oceans Institute, University of Western Australia, Crawley, WA Australia
| | - M. J. Ajemian
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 North, Fort Pierce, FL 34946 USA
| | - E. Gilman
- Pelagic Ecosystems Research Group, Honolulu, HI USA
- Heriot-Watt University, Edinburgh, UK
| | - E. Prasky
- Coastal Sustainability Institute, Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA 01908 USA
- Social Science Environmental Health Research Institute, Northeastern University, Boston, MA 02115 USA
| | - G. Jackson
- Department of Primary Industries and Regional Development, Western Australian Fisheries and Marine Research Laboratories, 39 Northside Drive, Hillarys, WA 6025 Australia
| |
Collapse
|
3
|
Abstract
Elasmobranchs (sharks, rays, and skates) are caught throughout fisheries globally, leading to over one-third of species being threatened with extinction1. Oceanic shark populations have undergone an average 71% decline over the last half century, owing to an 18-fold increase in relative fishing pressure2. Incidental capture or 'bycatch' is a primary driver of population declines, and poses an important challenge for species conservation3. This threat necessitates mitigation strategies that exist for sharks but are often focussed on haul-back and post-capture effects for longline fishing. We trialled a novel shark bycatch mitigation device ("SharkGuard") in a commercial longline fishery targeting bluefin tuna (Thunnus thynnus), where bycatch consists largely of blue sharks (Prionace glauca) and pelagic stingrays (Pteroplatytrygon violacea).
Collapse
|
4
|
Abrantes K, Barnett A, Soetaert M, Kyne PM, Laird A, Squire L, Seymour J, Wueringer BE, Sleeman J, Huveneers C. Potential of electric fields to reduce bycatch of highly threatened sawfishes. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Sawfishes are among the most threatened families of marine fishes and are susceptible to incidental capture in net fisheries. Since bycatch reduction devices currently used in trawl fisheries are not effective at reducing sawfish catches, new methods to minimise sawfish bycatch are needed. Ideally, these should affect sawfish behaviour and prevent contact with the fishing gear. We tested the effects of electric fields on sawfish behaviour to assess the potential of electric pulses in mitigating sawfish bycatch. Experiments were conducted in a tank where 2 electrodes were suspended in the water column, connected to a pulse generator, and placed across the swimming path of sawfish. Two largetooth sawfish Pristis pristis were tested in control conditions, in the presence of a baseline pulse, and of 5 variations of that pulse where 1 parameter (polarity, voltage, frequency, pulse shape, pulse duration) was altered at a time. Conditional inference trees were used to identify the effects of various parameters (e.g. treatment, individual) on reaction type, reaction distance, twitching presence and duration, and inter-approach times. Sawfish reacted to electric fields, but reaction distances were small (typically <1.2 m), and no field tested consistently led to reactions conducive to escaping from moving nets. The following parameters induced the most response in both individuals: bipolar current, rectangular shaped, 5-10 Hz, ~1500 µs duration, and 100 V. We recommend further research focussing on moving nets, testing a V-shaped electric array preceding the net mouth by at least 5 m, and testing a setup similar to electrotrawling.
Collapse
Affiliation(s)
- K Abrantes
- College of Science and Engineering, James Cook University, Townsville, Qld 4811, Australia
- Biopixel Oceans Foundation, Cairns, Qld 4870, Australia
| | - A Barnett
- College of Science and Engineering, James Cook University, Townsville, Qld 4811, Australia
- Biopixel Oceans Foundation, Cairns, Qld 4870, Australia
| | - M Soetaert
- Institute for Agricultural and Fisheries Research, Animal Sciences - Fisheries, Ankerstraat 1, 8400 Oostende, Belgium
| | - PM Kyne
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT 0815, Australia
| | - A Laird
- Northern Prawn Fishery Industry Pty Ltd, Caloundra, Qld 4551, Australia
| | - L Squire
- Cairns Marine, Cairns, Qld 4870, Australia
| | - J Seymour
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld 4870, Australia
| | - BE Wueringer
- Sharks and Rays Australia, PO Box 575, Bungalow, Cairns, Qld 4870, Australia
| | - J Sleeman
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld 4870, Australia
| | - C Huveneers
- College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA 5042, Australia
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|