Passive acoustic monitoring using a towed hydrophone array results in identification of a previously unknown beaked whale habitat

Little is known about the ecology of many beaked whale species, despite concerns raised by mass strandings linked to certain sources of anthropogenic noise. Here, we used passive acoustic monitoring to examine spatial and temporal patterns in beaked whale occurrence at six locations along the continental slope in the western North Atlantic Ocean. We analyzed 2642 days of recordings collected between 2011 and 2015, and identified echolocation signals from northern bottlenose whales (Hyperoodon ampullatus), Cuvier’s (Ziphius cavirostris), Sowerby’s (Mesoplodon bidens), Gervais’, (Mesoplodon europaeus), and Blainville’s (Mesoplodon densirostris) beaked whales, and one signal type of unknown origin. We recorded multiple species at each site, with detections generally occurring year-round, and observed latitudinal gradients and site-specific variation in relative species occurrence. Notably, we regularly detected Cuvier’s beaked whales in a region where they have not been commonly observed, and discovered potential habitat partitioning among Cuvier’s and Gervais’ beaked whales within their overlapping ranges. This information on the distribution and seasonal occurrence of North Atlantic beaked whale species offers new insight into patterns of habitat use, and provides a year-round baseline from which to assess potential anthropogenic impacts.

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Effective beam pattern of the Blainville's beaked whale (Mesoplodon densirostris) and implications for passive acoustic monitoring

The Journal of the Acoustical Society of America ◽

10.1121/1.4776177 ◽

2013 ◽

Vol 133 (3) ◽

pp. 1770-1784 ◽

Cited By ~ 26

Author(s):

Jessica Ward Shaffer ◽

David Moretti ◽

Susan Jarvis ◽

Peter Tyack ◽

Mark Johnson

Keyword(s):

Acoustic Monitoring ◽

Beam Pattern ◽

Beaked Whale ◽

Passive Acoustic Monitoring ◽

Passive Acoustic ◽

Effective Beam

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Passive and active, predator and prey: using acoustics to study interactions between cetaceans and forage fish

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw013 ◽

2016 ◽

Vol 73 (8) ◽

pp. 2075-2084 ◽

Cited By ~ 5

Author(s):

Joshua M. Lawrence ◽

Eric Armstrong ◽

Jonathan Gordon ◽

Susan Mærsk Lusseau ◽

Paul G. Fernandes

Keyword(s):

Moving Average ◽

Management Strategies ◽

Acoustic Monitoring ◽

Pelagic Fish ◽

Passive Acoustic Monitoring ◽

Survey Techniques ◽

Acoustic Methods ◽

Passive Acoustic ◽

Clyde Sea ◽

Hydrophone Array

AbstractFisheries acoustics surveys provide platforms for deploying passive acoustic equipment to detect cetacean vocalizations. Passive acoustic methods are developing as viable alternatives to visual surveys, particularly for small, inconspicuous species such as the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring using a towed hydrophone array was carried out during an acoustic survey of clupeids in the Clyde Sea and surrounding sea lochs to identify spatial relationships between porpoises and their prey. Methods were developed to process passive acoustic data, successfully identifying porpoise echolocation clicks while discriminating them from the transmitted 120-kHz echosounder pulse and its reflections. To date, this has been a confounding factor which has made these survey techniques potentially incompatible. The highest biomass of pelagic fish was detected in the northernmost parts of the survey region, as were the largest number of porpoises. A moving average was used to examine the scale of the relationships identified, and it was found that while porpoises show no significant preferences for pelagic prey numbers at the smallest scales, they do show significant avoidance of larger areas (5+ km) with very low pelagic fish biomass. This study demonstrates that high-frequency passive acoustic monitoring can be used effectively alongside multifrequency fisheries echosounder surveys to provide novel insights into the trophic interactions between these species, and that further work will hopefully prove useful in improving the efficacy of management strategies for harbour porpoises.

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