Dugong (<i>Dugong dugon</i>) vocalization patterns recorded by automatic underwater sound monitoring systems

Ichikawa, Katsuhiko; Tsutsumi, Chika; Arai, Nobuaki; Akamatsu, Tomonari; Shinke, Tomio; Hara, Takeshi; Adulyanukosol, Kanjana

doi:10.1121/1.2201468

Cited by 38 publications

(25 citation statements)

References 12 publications

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“…These methods are considered to be suitable for long-term automatic monitoring. The underwater sounds produced by aquatic animals can be used to monitor various characteristics of a species, including presence, behavior, and distribution ͑Nishimura and Conlon, 1994;van Parijs et al, 2002;Au and Benoit-Bird, 2003;Ichikawa et al, 2006;Tsutsumi et al, 2006͒. For example, researchers However, unlike visual observation, the T-POD system is not suitable for counting the specific number of animals because it is a monaural system.…”

Section: Introductionmentioning

confidence: 99%

Comparison of stationary acoustic monitoring and visual observation of finless porpoises

Kimura

Akamatsu

Wang

et al. 2009

The Journal of the Acoustical Society of America

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The detection performance regarding stationary acoustic monitoring of Yangtze finless porpoises Neophocaena phocaenoides asiaeorientalis was compared to visual observations. Three stereo acoustic data loggers ͑A-tag͒ were placed at different locations near the confluence of Poyang Lake and the Yangtze River, China. The presence and number of porpoises were determined acoustically and visually during each 1-min time bin. On average, porpoises were acoustically detected 81.7Ϯ 9.7% of the entire effective observation time, while the presence of animals was confirmed visually 12.7Ϯ 11.0% of the entire time. Acoustic monitoring indicated areas of high and low porpoise densities that were consistent with visual observations. The direction of porpoise movement was monitored using stereo beams, which agreed with visual observations at all monitoring locations. Acoustic and visual methods could determine group sizes up to five and ten individuals, respectively. While the acoustic monitoring method had the advantage of high detection probability, it tended to underestimate group size due to the limited resolution of sound source bearing angles. The stationary acoustic monitoring method proved to be a practical and useful alternative to visual observations, especially in areas of low porpoise density for long-term monitoring.

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Section: Introductionmentioning

confidence: 99%

Comparison of stationary acoustic monitoring and visual observation of finless porpoises

Kimura

Akamatsu

Wang

et al. 2009

The Journal of the Acoustical Society of America

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“…Researchers have exploited this characteristic to monitor aquatic animals using passive acoustic monitoring (PAM). PAM has been used to observe the presence, species identity, movement, and distribution of cetaceans (reviewed by Mellinger et al, 2007), pinnipeds (reviewed by Van Opzeeland et al, 2008), sirenians (e.g., Phillips et al, 2004;Ichikawa et al, 2006), and fish (reviewed by Luczkovich et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Variation in the production rate of biosonar signals in freshwater porpoises

Kimura

Akamatsu

Wang

et al. 2013

The Journal of the Acoustical Society of America

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The biosonar (click train) production rate of ten Yangtze finless porpoises and their behavior were examined using animal-borne data loggers. The sound production rate varied from 0 to 290 click trains per 10-min time interval. Large individual differences were observed, regardless of body size. Taken together, however, sound production did not differ significantly between daytime and nighttime. Over the 172.5 h of analyzed recordings, an average of 99.0% of the click trains were produced within intervals of less than 60 s, indicating that during a 1-min interval, the number of click trains produced by each porpoise was typically greater than one. Most of the porpoises exhibited differences in average swimming speed and depth between day and night. Swimming speed reductions and usage of short-range sonar, which relates to prey-capture attempts, were observed more often during nighttime. However, biosonar appears to be affected not only by porpoise foraging, but also by their sensory environment, i.e., the turbid Yangtze River system. These features will be useful for passive acoustic detection of the porpoises. Calculations of porpoise density or abundance should be conducted carefully because large individual differences in the sound production rate will lead to large estimation error.

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“…Electrophysiological measurements of hearing in manatees indicated peak sensitivity between 2 and 12 kHz (Bullock et al 1980, Klishin et al 1990. Dugong vocalisations cover the band from 0.5 to 18 kHz (Anderson & Barclay 1995, Ichikawa et al 2006. Peak frequencies of manatee vocalisations range from 3 to 7 kHz (Nowacek et al 2003).…”

Section: Modelling Pinger Detectabilitymentioning

confidence: 99%

Acoustic characterisation of bycatch mitigation pingers on shark control nets in Queensland, Australia

Erbe¹,

McPherson²

2012

Endang. Species. Res.

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The Queensland Shark Control Program (QSCP) uses pingers to prevent marine mammal entanglement in shark control nets along public beaches, in Queensland, Australia. Acoustic emissions of Fumunda F3 (designed for humpback whales) and F10 pingers (designed for dolphins) were measured and characterised. The acoustic signals consisted of tones (3 and 10 kHz, respectively) and harmonic overtones emitted for about 400 ms every 5 to 6 s. Directivity was more pronounced for the overtones. Broadband source levels were up to 135 dB re 1 µPa at 1 m for all pingers at all angles. Ambient noise was recorded in the vicinity of shark nets for 3 wk each quarter of 1 yr. Fish choruses, migrating humpback whales, dolphins, snapping shrimp, boats, sandpumps, wind and wave noise were identified. Beyond 1.5 km, pingers no longer contributed significantly to the ambient noise budget. Sound propagation was modelled to relate received pinger tones to measured ambient levels and to estimate the potential detection of pingers by local marine mammals (humpback whales, dugongs, dolphins). Mean transmitted levels were predicted to be audible over up to a few 100 m in range (depending on species). With currently 3 to 4 pingers per shark net of 200 m length, existing pinger type and arrangement were modelled to be adequate, even for marine mammals swimming straight at a net at top speed. Additional behavioural studies or long-term monitoring are needed to determine pinger efficacy.KEY WORDS: Pinger · Bycatch · ADD · Acoustic deterrence · Noise budget Resale or republication not permitted without written consent of the publisher Contribution to the Theme Section 'Techniques for reducing bycatch of marine mammals in gillnets'OPEN PEN

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Dugong (Dugong dugon) vocalization patterns recorded by automatic underwater sound monitoring systems

Cited by 38 publications

References 12 publications

Comparison of stationary acoustic monitoring and visual observation of finless porpoises

Comparison of stationary acoustic monitoring and visual observation of finless porpoises

Variation in the production rate of biosonar signals in freshwater porpoises

Acoustic characterisation of bycatch mitigation pingers on shark control nets in Queensland, Australia

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