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Laeta M, Oliveira JA, Siciliano S, Lambert O, Jensen FH, Galatius A. Cranial asymmetry in odontocetes: a facilitator of sonic exploration? ZOOLOGY 2023; 160:126108. [PMID: 37633185 DOI: 10.1016/j.zool.2023.126108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/28/2023]
Abstract
Directional cranial asymmetry is an intriguing condition that has evolved in all odontocetes which has mostly been associated with sound production for echolocation. In this study, we investigated how cranial asymmetry varies across odontocete species both in terms of quality (i.e., shape), and quantity (magnitude of deviation from symmetry). We investigated 72 species across all ten families of Odontoceti using two-dimensional geometric morphometrics. The average asymmetric shape was largely consistent across odontocetes - the rostral tip, maxillae, antorbital notches and braincase, as well as the suture crest between the frontal and interparietal bones were displaced to the right, whereas the nasal septum and premaxillae showed leftward shifts, in concert with an enlargement of the right premaxilla and maxilla. A clear phylogenetic signal related to asymmetric shape variation was identified across odontocetes using squared-change parsimony. The magnitude of asymmetry was widely variable across Odontoceti, with greatest asymmetry in Kogiidae, Monodontidae and Globicephalinae, followed by Physeteridae, Platanistidae and Lipotidae, while the asymmetry was lowest in Lissodelphininae, Phocoenidae, Iniidae and Pontoporiidae. Ziphiidae presented a wide spectrum of asymmetry. Generalized linear models explaining magnitude of asymmetry found associations with click source level while accounting for cranial size. Using phylogenetic generalized least squares, we reconfirm that source level and centroid size significantly predict the level of cranial asymmetry, with more asymmetric marine taxa generally consisting of bigger species emitting higher output sonar signal, i.e. louder sounds. Both characteristics theoretically support foraging at depth, the former by allowing extended diving and the latter being adaptive for prey detection at longer distances. Thus, cranial asymmetry seems to be an evolutionary pathway that allows odontocetes to devote more space for sound-generating structures associated with echolocation and thus increases biosonar search range and foraging efficiency beyond simple phylogenetic scaling predictions.
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Affiliation(s)
- Maíra Laeta
- Setor de Mastozoologia, Departamento de Vertebrados, Museu Nacional/Universidade Federal do Rio de Janeiro, 20941-160 Rio de Janeiro, RJ, Brazil.
| | - João A Oliveira
- Setor de Mastozoologia, Departamento de Vertebrados, Museu Nacional/Universidade Federal do Rio de Janeiro, 20941-160 Rio de Janeiro, RJ, Brazil
| | - Salvatore Siciliano
- Departamento de Ciências Biológicas, Escola Nacional de Saúde Pública Sergio Arouca/Fiocruz, 21040-360 Rio de Janeiro, RJ, Brazil; Grupo de Estudos de Mamíferos Marinhos da Região dos Lagos (GEMM-Lagos), Rua São José, 1.260, Praia Seca, 28970-000 Araruama, RJ, Brazil
| | - Olivier Lambert
- D.O. Terre et Histoire de la Vie, Institut royal des Sciences naturelles de Belgique, 1000 Brussels, Belgium
| | - Frants H Jensen
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Biology Department, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, MA 02543, USA; Biology Department, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - Anders Galatius
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
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Kimura SS, Sagara T, Yoda K, Ponnampalam LS. Habitat preference of two sympatric coastal cetaceans in Langkawi, Malaysia, as determined by passive acoustic monitoring. ENDANGER SPECIES RES 2022. [DOI: 10.3354/esr01194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Kimura SS, Sagara T, Yoda K, Ponnampalam LS. Acoustic identification of the sympatric species Indo-Pacific finless porpoise and Indo-Pacific humpback dolphin: an example from Langkawi, Malaysia. BIOACOUSTICS 2021. [DOI: 10.1080/09524622.2021.1998796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Satoko S. Kimura
- Distinguished Doctoral Program of Platforms, Center for Educational Program Promotion in Graduate School, Kyoto University, Yoshida Hon-machi, Sakyo-ku, Kyoto, Japan
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan
- Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Tomoka Sagara
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan
| | - Ken Yoda
- Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
| | - Louisa S. Ponnampalam
- The MareCet Research Organization, Subang Jaya, Malaysia
- Institute of Ocean and Earth Sciences, Universiti Malaya, Kuala Lumpur, Malaysia
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Dong L, Dong J, Caruso F, Zhao L, Li S. Temporal variation of the underwater soundscape in Jiaotou Bay, an Indo-Pacific humpback dolphin (Sousa chinensis) habitat off Hainan Island, China. Integr Zool 2021; 16:477-498. [PMID: 33818895 DOI: 10.1111/1749-4877.12530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The underwater soundscape is an important ecological element affecting numerous aquatic animals, in particular dolphins, which must identify salient cues from ambient ocean noise. In this study, temporal variations in the soundscape of Jiaotou Bay were monitored from February 2016 to January 2017, where a population of Indo-Pacific humpback dolphins (Sousa chinensis) has recently been a regular sighting. An autonomous acoustic recorder was deployed in shallow waters, and 1/3-octave band sound pressure levels (SPLs) were calculated with central frequencies ranging from 25 Hz to 40 kHz, then were grouped into 3 subdivided bands via cluster analysis. SPLs at each major band showed significant differences on a diel, fishing-related period, seasonal, and tidal phase scale. Anthropogenic noise generated by passing ships and underwater explosions were recorded in the study area. The fish and dolphin acoustic activities both exhibited diel and seasonal variations, but no tidal cycle patterns. A negative significant relationship between anthropogenic sound detection rates and dolphin detection rates were observed, and fish detection rates showed no effect on dolphin detection rates, indicating anthropogenic activity avoidance and no forced foraging in dolphins in the study area. The results provide fundamental insight into the acoustic dynamics of an important Indo-Pacific humpback dolphin habitat within a coastal area affected by a rapid increase in human activity, and demonstrate the need to protect animal habitat from anthropogenic noises.
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Affiliation(s)
- Lijun Dong
- Marine Mammal and Marine Bioacoustics Laboratory, Chinese Academy of Sciences, Institute of Deep-sea Science and Engineering, Sanya, China
| | - Jianchen Dong
- University of Chinese Academy of Sciences, Beijing, China
| | - Francesco Caruso
- Marine Mammal and Marine Bioacoustics Laboratory, Chinese Academy of Sciences, Institute of Deep-sea Science and Engineering, Sanya, China
| | - Likun Zhao
- University of Chinese Academy of Sciences, Beijing, China
| | - Songhai Li
- Marine Mammal and Marine Bioacoustics Laboratory, Chinese Academy of Sciences, Institute of Deep-sea Science and Engineering, Sanya, China.,Tropical Marine Science Institute, National University of Singapore, Singapore.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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Pedersen MB, Tønnesen P, Malinka CE, Ladegaard M, Johnson M, Aguilar de Soto N, Madsen PT. Echolocation click parameters of short-finned pilot whales (Globicephala macrorhynchus) in the wild. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 149:1923. [PMID: 33765819 DOI: 10.1121/10.0003762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Short-finned pilot whales (Globicephala macrorhynchus) are large, deep-diving predators with diverse foraging strategies, but little is known about their echolocation. To quantify the source properties of short-finned pilot whale clicks, we made 15 deployments off the coast of Tenerife of a deep-water hydrophone array consisting of seven autonomous time-synced hydrophone recorders (SoundTraps), enabling acoustic localization and quantification of click source parameters. Of 8185 recorded pilot whale clicks, 47 were classified as being recorded on-axis, with a mean peak-to-peak source level (SL) of 181 ± 7 dB re 1 μPa, a centroid frequency of 40 ± 4 kHz, and a duration of 57 ± 23 μs. A fit to a piston model yielded an estimated half-power (-3 dB) beam width of 13.7° [95% confidence interval (CI) 13.2°-14.5°] and a mean directivity index (DI) of 22.6 dB (95% CI 22.5-22.9 dB). These measured SLs and DIs are surprisingly low for a deep-diving toothed whale, suggesting we sampled the short-finned pilot whales in a context with little need for operating a long-range biosonar. The substantial spectral overlap with beaked whale clicks emitted in similar deep-water habitats implies that pilot whale clicks may constitute a common source of false detections in beaked whale passive acoustic monitoring efforts.
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Affiliation(s)
- M B Pedersen
- Marine Bioacoustics Lab, Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - P Tønnesen
- Marine Bioacoustics Lab, Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - C E Malinka
- Marine Bioacoustics Lab, Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - M Ladegaard
- Marine Bioacoustics Lab, Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - M Johnson
- Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C, Denmark
| | - N Aguilar de Soto
- Biodiversidad, Ecología Marina y Conservación (BIOECOMAC), University of La Laguna, 38206 La Laguna, Tenerife, Canary Islands, Spain
| | - P T Madsen
- Marine Bioacoustics Lab, Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
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Caruso F, Dong L, Lin M, Liu M, Xu W, Li S. Influence of acoustic habitat variation on Indo-Pacific humpback dolphin (Sousa chinensis) in shallow waters of Hainan Island, China. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:3871. [PMID: 32611150 DOI: 10.1121/10.0001384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 05/17/2020] [Indexed: 06/11/2023]
Abstract
The Indo-Pacific humpback dolphin (IPHD, Sousa chinensis) is a coastal species inhabiting tropical and warm-temperate waters. The presence of this vulnerable dolphin was recently discovered in shallow waters southwest of Hainan Island, China. The influence of the acoustic habitat on the distribution and behavior of IPHD was investigated using an array of passive acoustic platforms (n = 6) that spanned more than 100 km of coastline during a 75-day monitoring period. Its presence was assessed within 19 215 five-min recordings by classifying echolocation clicks using machine learning techniques. Spectrogram analysis was applied to further investigate the acoustic behavior of IPHD and to identify other prominent sound sources. The variation in the ambient noise levels was also measured to describe the spatiotemporal patterns of the acoustic habitat among the different sampling sites. Social and feeding sounds of IPHD (whistles and click-series of pulsed sounds) were identified together with other biological sources (finless porpoise, soniferous fishes, and snapping shrimps) and anthropogenic activities (ship noise, explosions, and sonars). Distribution, acoustic behavior, and habitat use of this nearshore dolphin species were strongly influenced by the abundance of soniferous fishes, and under similar conditions, the species was more acoustically active in locations with lower noise levels.
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Affiliation(s)
- Francesco Caruso
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya 572000, China
| | - Lijun Dong
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya 572000, China
| | - Mingli Lin
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya 572000, China
| | - Mingming Liu
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya 572000, China
| | - Wanxue Xu
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya 572000, China
| | - Songhai Li
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya 572000, China
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Yang L, Sharpe M, Temple AJ, Jiddawi N, Xu X, Berggren P. Description and classification of echolocation clicks of Indian Ocean humpback (Sousa plumbea) and Indo-Pacific bottlenose (Tursiops aduncus) dolphins from Menai Bay, Zanzibar, East Africa. PLoS One 2020; 15:e0230319. [PMID: 32168368 PMCID: PMC7069646 DOI: 10.1371/journal.pone.0230319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/26/2020] [Indexed: 11/18/2022] Open
Abstract
Passive acoustic monitoring (PAM) is a powerful method to study the occurrence, movement and behavior of echolocating odontocetes (toothed whales) in the wild. However, in areas occupied by more than one species, echolocation clicks need to be classified into species. The present study investigated whether the echolocation clicks produced by small, at-risk, resident sympatric populations of Indian Ocean humpback dolphin (Sousa plumbea) and Indo-Pacific bottlenose dolphin (Tursiops aduncus) in Menai Bay, Zanzibar, East Africa, could be classified to allow species specific monitoring. Underwater sounds of S. plumbea and T. aduncus groups were recorded using a SoundTrap 202HF in January and June-August 2015. Eight acoustic parameters, i.e. -10 dB duration, peak, centroid, lower -3 and lower -10 dB frequencies, and -3 dB, -10 dB and root-mean-squared bandwidth, were used to describe and compare the two species’ echolocation clicks. Statistical analyses showed that S. plumbea clicks had significantly higher peak, centroid, lower -3 and lower -10 dB frequencies compared to T. aduncus, whereas duration and bandwidth parameters were similar for the two species. Random Forest (RF) classifiers were applied to determine parameters that could be used to classify the two species from echolocation clicks and achieved 28.6% and 90.2% correct species classification rates for S. plumbea and T. aduncus, respectively. Both species were classified at a higher rate than expected at random, however the identified classifiers would only be useful for T. aduncus monitoring. The frequency and bandwidth parameters provided most power for species classification. Further study is necessary to identify useful classifiers for S. plumbea. This study represents a first step in acoustic description and classification of S. plumbea and T. aduncus in the western Indian Ocean region, with potential application for future acoustic monitoring of species-specific temporal and spatial occurrence in these sympatric species.
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Affiliation(s)
- Liangliang Yang
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, England, United Kingdom
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Matt Sharpe
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, England, United Kingdom
| | - Andrew J. Temple
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, England, United Kingdom
| | - Narriman Jiddawi
- Institute of Fisheries Research Zanzibar, Ministry of Agriculture, Natural Resources, Livestock and Fisheries, Zanzibar, Tanzania
| | - Xiaomei Xu
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
- * E-mail: (XX); (PB)
| | - Per Berggren
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, England, United Kingdom
- * E-mail: (XX); (PB)
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Gong Z, Dong L, Caruso F, Lin M, Liu M, Dong J, Li S. Echolocation signals of free-ranging pantropical spotted dolphins (Stenella attenuata) in the South China Sea. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:3480. [PMID: 31255156 DOI: 10.1121/1.5111742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Echolocation signals of free-ranging pantropical spotted dolphins (Stenella attenuata) in the western Pacific Ocean have not been studied much. This paper aims to describe the characteristics of echolocation signals of S. attenuata in the northern South China Sea. A six-arm star array with 13 hydrophones was used and a total of 131 on-axis clicks were identified to analyze the acoustic features of the echolocation signals of dolphins. The mean center frequency was 89 ± 13 kHz, with mean peak-to-peak sound source levels of 190 ± 6 dB re: 1 μPa @ 1 m. The mean -3 dB bandwidth and root-mean-square bandwidth were 62 ± 15 kHz and 26 ± 3 kHz, respectively, with mean -10 dB duration of 18 ± 4 μs and root-mean-square duration of 6 ± 2 μs. The results showed that click parameters of S. attenuata in the northern South China Sea are different from those of clicks of the species in Hawaii waters. The differences in click parameters may be due to both behavioral context and/or environmental adaptation of S. attenuata in different habitats.
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Affiliation(s)
- Zining Gong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Lijun Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Francesco Caruso
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Mingli Lin
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Mingming Liu
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Jianchen Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
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de Freitas M, Smith JN, Jensen FH, Beedholm K, Madsen PT. Echolocation click source parameters of Australian snubfin dolphins (Orcaella heinsohni). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:2564. [PMID: 29716291 DOI: 10.1121/1.5034174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Australian snubfin dolphin (Orcaella heinsohni) is endemic to Australian waters, yet little is known about its abundance and habitat use. To investigate the feasibility of Passive Acoustic Monitoring for snubfin dolphins, biosonar clicks were recorded in Cygnet Bay, Australia, using a four-element hydrophone array. Clicks had a mean source level of 200 ± 5 dB re 1 μPa pp, transmission directivity index of 24 dB, mean centroid frequency of 98 ± 9 kHz, and a root-mean-square bandwidth of 31 ± 3 kHz. Such properties lend themselves to passive acoustic monitoring, but are comparable to similarly-sized delphinids, thus requiring additional cues to discriminate between snubfins and sympatric species.
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Affiliation(s)
- Mafalda de Freitas
- Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
| | - Joshua N Smith
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia, 6150, Australia
| | - Frants H Jensen
- Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, 8000 Aarhus C, Denmark
| | - Kristian Beedholm
- Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
| | - Peter T Madsen
- Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
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Li S, Liu M, Dong L, Dong J, Wang D. Potential impacts of shipping noise on Indo-Pacific humpback dolphins and implications for regulation and mitigation: a review. Integr Zool 2018; 13:495-506. [PMID: 29316222 DOI: 10.1111/1749-4877.12304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Shipping noise is a widespread and relatively loud sound source among human-induced underwater sounds. The impacts of shipping noise are of special concern for Indo-Pacific humpback dolphins (Sousa chinensis), as they inhabit shallow and nearshore habitats and are highly dependent on sound for survival. This study synthesizes our current understanding of the potential impacts of shipping noise on Indo-Pacific humpback dolphins combined with knowledge on sound production and hearing of these animals and the impacts of noise on other whales and dolphins. For further protection and management of Indo-Pacific humpback dolphins and their habitats, shipping noise should be regulated and mitigated to modify sound from ships, to reduce overall noise levels, and to set more marine protected areas (MPAs) covering most Indo-Pacific humpback dolphin habitats with seasonal and geographical restrictions to avoid ensonification of shipping noise. The emphasis for future research should be on obtaining more baseline information about the population distribution, sound production, hearing capabilities at the population level, behavior, and stress hormones of the humpback dolphins under different noise conditions or under different noise-producing activities, and/or in high-noise areas compared with relatively quiet areas, and the noise characteristics of ships of different types, sizes and speeds.
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Affiliation(s)
- Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Mingming Liu
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lijun Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
| | - Jianchen Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ding Wang
- Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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Dong L, Liu M, Dong J, Li S. Acoustic occurrence detection of a newly recorded Indo-Pacific humpback dolphin population in waters southwest of Hainan Island, China. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:3198. [PMID: 29195470 DOI: 10.1121/1.5011170] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In 2014, Indo-Pacific humpback dolphins were recorded for the first time in waters southwest of Hainan Island, China. In this paper, the temporal occurrence of Indo-Pacific humpback dolphins in this region was detected by stationary passive acoustic monitoring. During the 130-day observation period (from January to July 2016), 1969 click trains produced by Indo-Pacific humpback dolphins were identified, and 262 ten-minute recording bins contained echolocation click trains of dolphins, of which 70.9% were at night and 29.1% were during the day. A diurnal rhythm with a nighttime peak in acoustic detections was found. Passive acoustic detections indicated that the Indo-Pacific humpback dolphins frequently occurred in this area and were detected mainly at night. This information may be relevant to conservation efforts for these dolphins in the near future.
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Affiliation(s)
- Lijun Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan Province, China
| | - Mingming Liu
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan Province, China
| | - Jianchen Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan Province, China
| | - Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan Province, China
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Liu M, Dong L, Lin M, Li S. Broadband ship noise and its potential impacts on Indo-Pacific humpback dolphins: Implications for conservation and management. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:2766. [PMID: 29195454 PMCID: PMC5680048 DOI: 10.1121/1.5009444] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 09/13/2017] [Accepted: 10/11/2017] [Indexed: 06/07/2023]
Abstract
Ship noise pollution has raised considerable concerns among regulatory agencies and cetacean researchers worldwide. There is an urgent need to quantify ship noise in coastal areas and assess its potential biological impacts. In this study, underwater broadband noise from commercial ships in a critical habitat of Indo-Pacific humpback dolphins was recorded and analyzed. Data analysis indicated that the ship noise caused by the investigated commercial ships with an average length of 134 ± 81 m, traveling at 18.8 ± 2.5 km/h [mean ± standard deviation (SD), n = 21] comprises mid-to-high components with frequencies approaching and exceeding 100 kHz, and the ship noise could be sensed auditorily by Indo-Pacific humpback dolphins within most of their sensitive frequency range. The contributions of ship noise to ambient noise were highest in two third-octave bands with center frequencies of 8 and 50 kHz, which are within the sensitive hearing range of Indo-Pacific humpback dolphins and overlap the frequency of sounds that are biologically significant to the dolphins. It is estimated that ship noise in these third-octave bands can be auditorily sensed by and potentially affect the dolphins within 2290 ± 1172 m and 848 ± 358 m (mean ± SD, n = 21), respectively.
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Affiliation(s)
- Mingming Liu
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Lijun Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Mingli Lin
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
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Song Z, Zhang Y, Thornton SW, Li S, Dong J. The influence of air-filled structures on wave propagation and beam formation of a pygmy sperm whale (Kogia breviceps) in horizontal and vertical planes. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:2443. [PMID: 29092606 DOI: 10.1121/1.5008855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The wave propagation, sound field, and transmission beam pattern of a pygmy sperm whale (Kogia breviceps) were investigated in both the horizontal and vertical planes. Results suggested that the signals obtained at both planes were similarly characterized with a high peak frequency and a relatively narrow bandwidth, close to the ones recorded from live animals. The sound beam measured outside the head in the vertical plane was narrower than that of the horizontal one. Cases with different combinations of air-filled structures in both planes were used to study the respective roles in controlling wave propagation and beam formation. The wave propagations and beam patterns in the horizontal and vertical planes elucidated the important reflection effect of the spermaceti and vocal chambers on sound waves, which was highly significant in forming intensive forward sound beams. The air-filled structures, the forehead soft tissues and skull structures formed wave guides in these two planes for emitted sounds to propagate forward.
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Affiliation(s)
- Zhongchang Song
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, People's Republic of China
| | - Yu Zhang
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, People's Republic of China
| | - Steven W Thornton
- Coastwise Consulting, Inc. 173 Virgina Avenue, Athens, Georgia 30601, USA
| | - Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, People's Republic of China
| | - Jianchen Dong
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, People's Republic of China
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Fang L, Wu Y, Wang K, Pine MK, Wang D, Li S. The echolocation transmission beam of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:771. [PMID: 28863578 PMCID: PMC5552390 DOI: 10.1121/1.4996499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 07/02/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
While the transmission beam of odontocetes has been described in a number of studies, the majority of them that have measured the transmission beam in two dimensions were focused on captive animals. Within the current study, a dedicated cross hydrophone array with nine elements was used to investigate the echolocation transmission beam of free-ranging Indo-Pacific humpback dolphins. A total of 265 on-axis clicks were analyzed, from which the apparent peak to peak source levels ranged between 168 to 207 dB (mean 184.5 dB ± 6.6 dB). The 3-dB beam width along the horizontal and vertical plane was 9.6° and 7.4°, respectively. Measured separately, the directivity index of the horizontal and vertical plane was 12.6 and 13.5 dB, respectively, and the overall directivity index (both planes combined) was 29.5 dB. The beam shape was slightly asymmetrical along the horizontal and vertical axis. Compared to other species, the characteristics of the transmitting beam of Indo-Pacific humpback dolphins were relatively close to the bottlenose dolphin (Tursiops truncatus), likely due to the similarity in the peak frequency and waveform of echolocation clicks and comparable body sizes of the two species.
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Affiliation(s)
- Liang Fang
- South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Lab of Marine Bioresource and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, People's Republic of China
| | - Yuping Wu
- South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Lab of Marine Bioresource and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, People's Republic of China
| | - Kexiong Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Matthew K Pine
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Ding Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, People's Republic of China
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Temple AJ, Tregenza N, Amir OA, Jiddawi N, Berggren P. Spatial and Temporal Variations in the Occurrence and Foraging Activity of Coastal Dolphins in Menai Bay, Zanzibar, Tanzania. PLoS One 2016; 11:e0148995. [PMID: 26934473 PMCID: PMC4774871 DOI: 10.1371/journal.pone.0148995] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 01/25/2016] [Indexed: 11/21/2022] Open
Abstract
Understanding temporal patterns in distribution, occurrence and behaviour is vital for the effective conservation of cetaceans. This study used cetacean click detectors (C-PODs) to investigate spatial and temporal variation in occurrence and foraging activity of the Indo-Pacific bottlenose (Tursiops aduncus) and Indian Ocean humpback (Sousa plumbea) dolphins resident in the Menai Bay Conservation Area (MBCA), Zanzibar, Tanzania. Occurrence was measured using detection positive minutes. Inter-click intervals were used to identify terminal buzz vocalisations, allowing for analysis of foraging activity. Data were analysed in relation to spatial (location) and temporal (monsoon season, diel phase and tidal phase) variables. Results showed significantly increased occurrence and foraging activity of dolphins in southern areas and during hours of darkness. Higher occurrence at night was not explained by diel variation in echolocation rate and so were considered representative of occurrence patterns. Both tidal phase and monsoon season influenced occurrence but results varied among sites, with no general patterns found. Foraging activity was greatest during hours of darkness, High water and Flood tidal phases. Comparisons of echolocation data among sites suggested differences in the broadband click spectra of MBCA dolphins, possibly indicative of species differences. These dolphin populations are threatened by unsustainable fisheries bycatch and tourism activities. The spatial and temporal patterns identified in this study have implications for future conservation and management actions with regards to these two threats. Further, the results indicate future potential for using passive acoustics to identify and monitor the occurrence of these two species in areas where they co-exist.
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Affiliation(s)
- Andrew J. Temple
- School of Marine Science & Technology, Newcastle University, Newcastle-upon-Tyne, United Kingdom
- * E-mail:
| | - Nick Tregenza
- Chelonia Limited, The Barkhouse, North Cliff, Mousehole, Cornwall, United Kingdom
| | - Omar A. Amir
- Ministry of Livestock and Fisheries, Nyangumi House, Maruhubi Street, Zanzibar, Tanzania
| | - Narriman Jiddawi
- Institute of Marine Sciences, Dar es Salaam University, Zanzibar, Tanzania
| | - Per Berggren
- School of Marine Science & Technology, Newcastle University, Newcastle-upon-Tyne, United Kingdom
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