Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets
The need to minimize bycatch of toothed whales (odontocetes) in gillnets has long been recognized, because they are often top predators and thus essential to ecosystem resilience. It is likely that a key to achieving this goal is the improvement of gillnet acoustic visibility, because these species...
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2020
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ftdtupubl:oai:pure.atira.dk:publications/0d4163ba-5b2f-4bcf-b808-5ff4af8fa824 2024-06-09T07:49:57+00:00 Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets Kratzer, Isabella M.F. Schäfer, Ingo Stoltenberg, Arne Chladek, Jérôme C. Kindt-Larsen, Lotte Larsen, Finn Stepputtis, Daniel 2020 application/pdf https://orbit.dtu.dk/en/publications/0d4163ba-5b2f-4bcf-b808-5ff4af8fa824 https://doi.org/10.3389/fmars.2020.00539 https://backend.orbit.dtu.dk/ws/files/217907203/fmars_07_00539.pdf eng eng https://orbit.dtu.dk/en/publications/0d4163ba-5b2f-4bcf-b808-5ff4af8fa824 info:eu-repo/semantics/openAccess Kratzer , I M F , Schäfer , I , Stoltenberg , A , Chladek , J C , Kindt-Larsen , L , Larsen , F & Stepputtis , D 2020 , ' Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets ' , Frontiers in Marine Science , vol. 7 , 539 . https://doi.org/10.3389/fmars.2020.00539 Bycatch Odontocetes Resonance Target strength Acrylic glass Gillnet article 2020 ftdtupubl https://doi.org/10.3389/fmars.2020.00539 2024-05-15T00:13:14Z The need to minimize bycatch of toothed whales (odontocetes) in gillnets has long been recognized, because they are often top predators and thus essential to ecosystem resilience. It is likely that a key to achieving this goal is the improvement of gillnet acoustic visibility, because these species use underwater sonar for orientation. Previous work on increasing gillnet detectability for echolocating animals by making the nets more recognizable has been based on trial and error, without understanding the fundamental acoustic properties of the tested modifications. Consequently, these studies have produced mixed and sometimes contradictory results. We systematically identified small, passive reflective objects that can improve the visibility of gillnets at a broad range of frequencies, i.e., for many odontocetes. We simulated the acoustic reflectivity of a wide range of materials in different shapes, sizes, and environmental conditions, with a focus on polymer materials. We verified the simulation results experimentally and calculated detection distances of the selected modifications. For example, if 8 mm acrylic glass spheres are attached to the net at intervals smaller than 0.5 m, the spheres have the same target strength (TS) at 130 kHz as the most recognizable part of a gillnet, the floatline. Modifications of the netting material itself, e.g., using barium sulfate additives, do not substantially increase the acoustic reflectivity of the net. Article in Journal/Newspaper toothed whales Technical University of Denmark: DTU Orbit Frontiers in Marine Science 7 |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
topic |
Bycatch Odontocetes Resonance Target strength Acrylic glass Gillnet |
spellingShingle |
Bycatch Odontocetes Resonance Target strength Acrylic glass Gillnet Kratzer, Isabella M.F. Schäfer, Ingo Stoltenberg, Arne Chladek, Jérôme C. Kindt-Larsen, Lotte Larsen, Finn Stepputtis, Daniel Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets |
topic_facet |
Bycatch Odontocetes Resonance Target strength Acrylic glass Gillnet |
description |
The need to minimize bycatch of toothed whales (odontocetes) in gillnets has long been recognized, because they are often top predators and thus essential to ecosystem resilience. It is likely that a key to achieving this goal is the improvement of gillnet acoustic visibility, because these species use underwater sonar for orientation. Previous work on increasing gillnet detectability for echolocating animals by making the nets more recognizable has been based on trial and error, without understanding the fundamental acoustic properties of the tested modifications. Consequently, these studies have produced mixed and sometimes contradictory results. We systematically identified small, passive reflective objects that can improve the visibility of gillnets at a broad range of frequencies, i.e., for many odontocetes. We simulated the acoustic reflectivity of a wide range of materials in different shapes, sizes, and environmental conditions, with a focus on polymer materials. We verified the simulation results experimentally and calculated detection distances of the selected modifications. For example, if 8 mm acrylic glass spheres are attached to the net at intervals smaller than 0.5 m, the spheres have the same target strength (TS) at 130 kHz as the most recognizable part of a gillnet, the floatline. Modifications of the netting material itself, e.g., using barium sulfate additives, do not substantially increase the acoustic reflectivity of the net. |
format |
Article in Journal/Newspaper |
author |
Kratzer, Isabella M.F. Schäfer, Ingo Stoltenberg, Arne Chladek, Jérôme C. Kindt-Larsen, Lotte Larsen, Finn Stepputtis, Daniel |
author_facet |
Kratzer, Isabella M.F. Schäfer, Ingo Stoltenberg, Arne Chladek, Jérôme C. Kindt-Larsen, Lotte Larsen, Finn Stepputtis, Daniel |
author_sort |
Kratzer, Isabella M.F. |
title |
Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets |
title_short |
Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets |
title_full |
Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets |
title_fullStr |
Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets |
title_full_unstemmed |
Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets |
title_sort |
determination of optimal acoustic passive reflectors to reduce bycatch of odontocetes in gillnets |
publishDate |
2020 |
url |
https://orbit.dtu.dk/en/publications/0d4163ba-5b2f-4bcf-b808-5ff4af8fa824 https://doi.org/10.3389/fmars.2020.00539 https://backend.orbit.dtu.dk/ws/files/217907203/fmars_07_00539.pdf |
genre |
toothed whales |
genre_facet |
toothed whales |
op_source |
Kratzer , I M F , Schäfer , I , Stoltenberg , A , Chladek , J C , Kindt-Larsen , L , Larsen , F & Stepputtis , D 2020 , ' Determination of Optimal Acoustic Passive Reflectors to Reduce Bycatch of Odontocetes in Gillnets ' , Frontiers in Marine Science , vol. 7 , 539 . https://doi.org/10.3389/fmars.2020.00539 |
op_relation |
https://orbit.dtu.dk/en/publications/0d4163ba-5b2f-4bcf-b808-5ff4af8fa824 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3389/fmars.2020.00539 |
container_title |
Frontiers in Marine Science |
container_volume |
7 |
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1801382890972381184 |