The Experts below are selected from a list of 44460 Experts worldwide ranked by ideXlab platform
Ding Wang - One of the best experts on this subject based on the ideXlab platform.
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Assessing the Underwater Acoustics of the World’s Largest Vibration Hammer (OCTA-KONG) and Its Potential Effects on the Indo-Pacific Humpbacked
2016Co-Authors: Dolphin Chinensis, Zhitao Wang, Guoqin Duan, Hanjiang Cao, Jianchang Liu, Kexiong Wang, Ding WangAbstract:Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world’s largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species ’ social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighte
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assessing the underwater acoustics of the world s largest vibration hammer octa kong and its potential effects on the indo pacific humpbacked dolphin Sousa chinensis
PLOS ONE, 2014Co-Authors: Zhitao Wang, Guoqin Duan, Hanjiang Cao, Jianchang Liu, Kexiong Wang, Ding WangAbstract:Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world's largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species' social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighted cumulative SSELs exceeded the acoustic threshold levels for the onset of temporary threshold shift, a type of potentially recoverable auditory damage resulting from prolonged sound exposure. These findings may aid in the identification and design of appropriate mitigation methods, such as the use of air bubble curtains, "soft start" and "power down" techniques.
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whistle characteristics of free ranging indo pacific humpback dolphins Sousa chinensis in sanniang bay china
Journal of the Acoustical Society of America, 2013Co-Authors: Zhitao Wang, Kexiong Wang, Liang Fang, Wenjing Shi, Ding WangAbstract:Broadband recording systems were adapted to characterize the whistle characteristics of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in Sanniang Bay, China. A total of 4630 whistles were recorded, of which 2651 with legible contours and relatively good signal-to-noise ratios were selected for statistical analysis. Of the six tonal types (i.e., flat, down, rise, convex, U-shaped, and sine), flat (N - 1426; 39.45%) was the most predominant, followed by down (N - 754; 23.35%) and rise (N - 489; 12.34%). The whistles showed a short duration (mean +/- SD: 370.19 +/- 285.61 ms; range: 29-2923 ms), a broad frequency range (fundamental contour ranged from 0.52 to 33 kHz), and two harmonics (mean +/- SD: 1.90 +/- 2.74, with the maximum frequency of harmonics beyond 96 kHz). Whistles without gaps and stairs accounted for 76.7% and 86.4%, respectively. No significant interspecies differences in frequency parameters were observed compared with S. teuszii, which is inconsistent with morphological taxonomies but confirms phylogenetic results, thus suggesting a close relation between Chinese S. chinensis and Atlantic S. teuszii. Significant intra- and interspecific differences in the genus Sousa were also observed, indicating that animal vocalization may not be limited by genetically determined traits but could also be a function of local habitat adaptation. (C) 2013 Acoustical Society of America.
Thomas Jefferson - One of the best experts on this subject based on the ideXlab platform.
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humpback dolphins Sousa teuszii s plumbea s chinensis and s sahulensis
2018Co-Authors: Guido J. Parra, Thomas JeffersonAbstract:Summary Humpback dolphins (genus Sousa ) are medium-sized delphinids found in shallow ( Sousa teuszii ), (2) Indian Ocean humpback ( S. plumbea ), (3) Indo-Pacific humpback ( S. chinensis ), and (4) Australian humpback ( S. sahulensis ) dolphins. Information on the ecology, behavior and life history of all humpback dolphins remains scarce. Most study populations to date indicate that all species occur in small numbers, with most populations confirmed or suspected to be declining and threatened. Major threats affecting all species include habitat degradation and loss, and entanglement in fishing gear. Research efforts and conservation actions tailored to each species are needed to assess anthropogenic impacts, and develop strategies to eliminate or mitigate threats.
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re assessment of the conservation status of the indo pacific humpback dolphin Sousa chinensis using the iucn red list criteria
Advances in Marine Biology, 2016Co-Authors: Thomas Jefferson, Brian D SmithAbstract:Abstract The IUCN Red List designation of the Indo-Pacific humpback dolphin (Sousa chinensis) is re-assessed in light of its newly recognized taxonomic status (it has recently been separated into three species) and findings that humpback dolphins along the coast of Bangladesh, and possibly eastern India, are phylogenetically distinct from other members of the Sousa genus. Sousa chinensis is found in Southeast/South Asia (in both the Indian and Pacific oceans), from at least the southeastern Bay of Bengal east to central China, and then south to the Indo-Malay Archipelago. There are no global population estimates, and the sum of available abundance estimates add up to about 5700 individuals, although only a portion of the range has been covered by surveys. This species occurs in shallow (
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taxonomic revision of the humpback dolphins Sousa spp and description of a new species from australia
Marine Mammal Science, 2014Co-Authors: Thomas Jefferson, Howard C RosenbaumAbstract:The taxonomy of the humpback dolphin genus Sousa has been controversial and unsettled for centuries, but recent work indicates that there are several valid species. A review of multiple lines of evidence from skeletal morphology, external morphology, coloration, molecular genetics, and biogeography, in combination provides strong support for the recognition of four species of Sousa. These include S. teuszii (Kukenthal, 1892), a species with uniform gray coloration and a prominent dorsal hump, which is found in the Atlantic Ocean off West Africa. The species S. plumbea (G. Cuvier, 1829) has similar external appearance to S. teuszii, but has a more pointed dorsal fin. It occurs in the Indian Ocean from South Africa to Myanmar (Burma). The original taxon, S. chinensis (Osbeck, 1765), is reserved for the species that has a larger dorsal fin with no prominent hump, and largely white adult coloration. It ranges from eastern India to central China and throughout Southeast Asia. Finally, we describe a new species of Sousa, the Australian humpback dolphin, which occurs in the waters of the Sahul Shelf from northern Australia to southern New Guinea. It has a lower dorsal fin, more extensive dark color on the body, and a dorsal “cape.” It is separated from the Indo-Pacific humpback dolphin by a wide distributional gap that coincides with Wallace's Line.
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impacts of fisheries on the critically endangered humpback dolphin Sousa chinensis population in the eastern taiwan strait
Endangered Species Research, 2013Co-Authors: Elisabeth Slooten, Thomas Jefferson, Samuel K Hung, John Y Wang, Sarah Z Dungan, Karin A Forney, Kimberly N Riehl, Lorenzo Rojas Bracho, Peter S Ross, Ashley WeeAbstract:Biological and fisheries data were analysed to assess the impact of fisheries mortality on a Critically Endangered subpopulation of 30% of the ETS Sousa subpopulation exhibited injuries caused by fishing gear. Three individuals were photographed with fishing gear attached to their bodies, and 1 dolphin was found dead with fresh injuries caused by fishing gear. To ensure recovery of ETS Sousa, mortality due to human causes should be reduced to <1 individual every 7 yr. Fisheries bycatch is the most serious threat to these dolphins and needs to be eliminated as soon as possible to avoid extinction. Preventing the use of trammel nets, other gillnets and trawling throughout their habitat would be the single most effective conservation measure for ETS Sousa in the short term. Other fishing methods are available, and using the most selective, sustainable fishing methods available will benefit not only dolphins but also fish stocks, seabirds and other species, as well as the fishing industry, which depends on these species for its long-term viability. However, in the short term, there are costs associated with switching to more selective fishing gear.
Per Berggren - One of the best experts on this subject based on the ideXlab platform.
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population size distribution and behavior of indo pacific bottlenose tursiops aduncus and humpback Sousa chinensis dolphins off the south coast of zanzibar
Marine Mammal Science, 2006Co-Authors: Eva Stensland, Ida Carlen, Anna Sarnblad, Anders Bignert, Per BerggrenAbstract:Indo-Pacific bottlenose (Tursiops aduncus) and humpback dolphins (Sousa chinensis) off the south coast of Zanzibar, East Africa, have been subject to both direct and indirect takes as well as distu ...
Zhitao Wang - One of the best experts on this subject based on the ideXlab platform.
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Assessing the Underwater Acoustics of the World’s Largest Vibration Hammer (OCTA-KONG) and Its Potential Effects on the Indo-Pacific Humpbacked
2016Co-Authors: Dolphin Chinensis, Zhitao Wang, Guoqin Duan, Hanjiang Cao, Jianchang Liu, Kexiong Wang, Ding WangAbstract:Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world’s largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species ’ social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighte
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assessing the underwater acoustics of the world s largest vibration hammer octa kong and its potential effects on the indo pacific humpbacked dolphin Sousa chinensis
PLOS ONE, 2014Co-Authors: Zhitao Wang, Guoqin Duan, Hanjiang Cao, Jianchang Liu, Kexiong Wang, Ding WangAbstract:Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world's largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species' social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighted cumulative SSELs exceeded the acoustic threshold levels for the onset of temporary threshold shift, a type of potentially recoverable auditory damage resulting from prolonged sound exposure. These findings may aid in the identification and design of appropriate mitigation methods, such as the use of air bubble curtains, "soft start" and "power down" techniques.
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whistle characteristics of free ranging indo pacific humpback dolphins Sousa chinensis in sanniang bay china
Journal of the Acoustical Society of America, 2013Co-Authors: Zhitao Wang, Kexiong Wang, Liang Fang, Wenjing Shi, Ding WangAbstract:Broadband recording systems were adapted to characterize the whistle characteristics of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in Sanniang Bay, China. A total of 4630 whistles were recorded, of which 2651 with legible contours and relatively good signal-to-noise ratios were selected for statistical analysis. Of the six tonal types (i.e., flat, down, rise, convex, U-shaped, and sine), flat (N - 1426; 39.45%) was the most predominant, followed by down (N - 754; 23.35%) and rise (N - 489; 12.34%). The whistles showed a short duration (mean +/- SD: 370.19 +/- 285.61 ms; range: 29-2923 ms), a broad frequency range (fundamental contour ranged from 0.52 to 33 kHz), and two harmonics (mean +/- SD: 1.90 +/- 2.74, with the maximum frequency of harmonics beyond 96 kHz). Whistles without gaps and stairs accounted for 76.7% and 86.4%, respectively. No significant interspecies differences in frequency parameters were observed compared with S. teuszii, which is inconsistent with morphological taxonomies but confirms phylogenetic results, thus suggesting a close relation between Chinese S. chinensis and Atlantic S. teuszii. Significant intra- and interspecific differences in the genus Sousa were also observed, indicating that animal vocalization may not be limited by genetically determined traits but could also be a function of local habitat adaptation. (C) 2013 Acoustical Society of America.
Eva Stensland - One of the best experts on this subject based on the ideXlab platform.
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population size distribution and behavior of indo pacific bottlenose tursiops aduncus and humpback Sousa chinensis dolphins off the south coast of zanzibar
Marine Mammal Science, 2006Co-Authors: Eva Stensland, Ida Carlen, Anna Sarnblad, Anders Bignert, Per BerggrenAbstract:Indo-Pacific bottlenose (Tursiops aduncus) and humpback dolphins (Sousa chinensis) off the south coast of Zanzibar, East Africa, have been subject to both direct and indirect takes as well as distu ...
