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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.
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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
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Green ME, D’Anastasi BR, Hobbs JPA, Feldheim K, McAuley R, Peverell S, Stapley J, Johnson G, Appleyard SA, White WT, Simpfendorfer CA, van Herwerden L. Mixed-marker approach suggests maternal philopatry and sex-biased behaviours of narrow sawfish Anoxypristis cuspidata. ENDANGER SPECIES RES 2018. [DOI: 10.3354/esr00912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Stein RW, Mull CG, Kuhn TS, Aschliman NC, Davidson LNK, Joy JB, Smith GJ, Dulvy NK, Mooers AO. Global priorities for conserving the evolutionary history of sharks, rays and chimaeras. Nat Ecol Evol 2018; 2:288-298. [PMID: 29348644 DOI: 10.1038/s41559-017-0448-4] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 12/08/2017] [Indexed: 01/06/2023]
Abstract
In an era of accelerated biodiversity loss and limited conservation resources, systematic prioritization of species and places is essential. In terrestrial vertebrates, evolutionary distinctness has been used to identify species and locations that embody the greatest share of evolutionary history. We estimate evolutionary distinctness for a large marine vertebrate radiation on a dated taxon-complete tree for all 1,192 chondrichthyan fishes (sharks, rays and chimaeras) by augmenting a new 610-species molecular phylogeny using taxonomic constraints. Chondrichthyans are by far the most evolutionarily distinct of all major radiations of jawed vertebrates-the average species embodies 26 million years of unique evolutionary history. With this metric, we identify 21 countries with the highest richness, endemism and evolutionary distinctness of threatened species as targets for conservation prioritization. On average, threatened chondrichthyans are more evolutionarily distinct-further motivating improved conservation, fisheries management and trade regulation to avoid significant pruning of the chondrichthyan tree of life.
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Affiliation(s)
- R William Stein
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Christopher G Mull
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
| | | | | | - Lindsay N K Davidson
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Jeffrey B Joy
- BC Centre for Excellence in HIV/AIDS, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gordon J Smith
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Nicholas K Dulvy
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
| | - Arne O Mooers
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
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Papastamatiou YP, Dean Grubbs R, Imhoff JL, Gulak SJ, Carlson JK, Burgess GH. A subtropical embayment serves as essential habitat for sub-adults and adults of the critically endangered smalltooth sawfish. Glob Ecol Conserv 2015. [DOI: 10.1016/j.gecco.2015.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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