Publications

Rice's whale occurrence in the western Gulf of Mexico from passive acoustic recordings

Soldevilla, M. S. | Debich, A. J. | Pérez-Carballo, I. | Jarriel, S. | Frasier, K. E.| Garrison, L. P. | Gracia, A. | Hildebrand, M. J.| Rosel, P. | Serrano, A.

2024 Jan Rice's Whale |

Rice's whales (Balaenoptera ricei) are one of the most endangered marine mammal species in the world. Their known distribution is restricted to the Gulf of Mexico (GoMx) and basic knowledge of their ecology is limited. In their core distribution area along the northeastern GoMx shelf break (Rosel & Garrison, 2021), their abundance was estimated at 51 individuals, 95% CI [20, 130], based on line transect surveys conducted during 2017 and 2018 (Garrison et al., 2020) ...

View More

Odontocete detections are linked to oceanographic conditions in the Hawaiian Archipelago

Ziegenhorn, M. A. | Hildebrand, J. A. | Oleson E. M. | Baird R. W. | Baumann-Pickering, S.

2023 Nov Hawaii | Odontocete

Understanding environmental drivers of species’ behavior is key for successful conservation. Within cetacean research, studies focused on understanding such drivers often consider local conditions (e.g., sea surface temperature), but rarely include large-scale, long-term parameters such as climate indices. Here we make use of long-term passive acoustic monitoring data to examine relationships between eight classes of toothed whales and climate indices, ...

View More

Resonance of the tympanoperiotic complex of fin whales with implications for their low frequency hearing

Morris, M. A. | Krysl. P. | Hildebrand, J. | Cranford, T.

2023 Oct FinWhale | Hearing

The tympanoperiotic complex (TPC) bones of the fin whale skull were studied using experimental measurements and simulation modeling to provide insight into the low frequency hearing of these animals. The study focused on measuring the sounds emitted by the left and right TPC bones when the bones were tapped at designated locations.

View More

Spatial and temporal separation of toothed whales in the western North Atlantic

Cohen, R. E. | Frasier, K. E.| Baumann-Pickering, S. | Hildebrand, J. A.

2023 Oct Odontocete | Northwest Atlantic | BeakedWhale

A diverse group of toothed whale species inhabits the pelagic habitats of the western North Atlantic, competing for overlapping prey resources. Historical data deficits have limited fundamental research into many of these species, such as establishing baselines of distribution and abundance, so their occurrence and habitat use patterns are not well characterized.

View More

Impact of ship noise on the underwater soundscape of Eclipse Sound in the northeastern Canadian Arctic

Jones, J. M. | Westdal, K. H.| Ootoowak, A. J. | Wiggins, S. M. | Hildebrand, J. A.

2023 Sept Ship Noise | Arctic

Eclipse Sound, in the northeastern Canadian Arctic, has experienced a substantial increase in ship traffic due to growing tourism and industrial development in the region. This study aims to describe the natural soundscape as well as to assess the noise levels associated with shipping.

View More

Kinematics and energetics of foraging behavior in Rice’s whales of the Gulf of Mexico

Kok, A. C. M. | Hildebrand, M. J.| MacArdle, M. | Martinez, A. | Garrison, L. P. | Soldevilla, M. S. | Hildebrand, J. A.

2023 June Rice's Whale |

Rorqual foraging behavior varies with species, prey type and foraging conditions, and can be a determining factor for their fitness. Little is known about the foraging ecology of Rice’s whales (Balaenoptera ricei), an endangered species with a population of fewer than 100 individuals. Suction cup tags were attached to two Rice’s whales ...

View More

Bayesian detection and tracking of odontocetes in 3-D from their echolocation clicks

Jang, J. | Meyer, F. | Snyder, E. R. | Wiggins, S. M. | Baumann-Pickering, S. | Hildebrand, J. A.

2023 May Acoustic Tracking |

Localization and tracking of marine animals can reveal key insights into their behaviors underwater that would otherwise remain unexplored. A promising nonintrusive approach to obtaining location information of marine animals is to process their bioacoustic signals, which are passively recorded using multiple hydrophones. In this paper, a data processing chain that automatically detects and tracks multiple odontocetes (toothed whales) in three dimensions (3-D) from their echolocation clicks …

View More

Retrofit-induced changes in the radiated noise and monopole source levels of container ships

Zobell, V. M. | Gassmann, M. | Kindberg, L. B. | Wiggins, S. M. | Hildebrand, J. A. | Frasier, K. E.

2023 March Ship Noise / Ocean Traffic |

The container shipping line Maersk undertook a Radical Retrofit to improve the energy efficiency of twelve sister container ships. Noise reduction, identified as a potential added benefit of the retrofitting effort, was investigated in this study. A passive acoustic recording dataset from the Santa Barbara Channel off Southern California was used to compile over 100 opportunistic vessel transits of the twelve G-Class container ships, pre- and post-retrofit. …

View More

SoundScape learning: An automatic method for separating fish chorus in marine soundscapes

Kim, E. B. | Frasier, K. E. | McKenna, M. F. | Kok, A. C. | Peavey Reeves, L. E. | Ostreich, W. K. | Arrieta, G. | Wiggins, S. M. | Baumann-Pickering, S.

2023 March Passive Acoustics | Soundscape | Fish | California

Marine soundscapes provide the opportunity to non-invasively learn about, monitor, and conserve ecosystems. Some fishes produce sound in chorus, often in association with mating, and there is much to learn about fish choruses and the species producing them. Manually analyzing years of acoustic data is increasingly unfeasible, and is especially challenging with fish chorus, as multiple fish choruses can co-occur in time and frequency and can overlap with vessel noise and other transient sounds. This study proposes an unsupervised automated method, called SoundScape Learning (SSL), to separate fish chorus from soundscape using an integrated technique …

View More

Geographic differences in Blainville's beaked whale (Mesoplodon densirostris) echolocation clicks

Baumann-Pickering, S. | Trickey, J. S. | Solsona Berga, A. | Rice, A. | Oleson, E. M. | Hildebrand, J. A. | Frasier, K. E.

2023 April Passive Acoustics | Distribution | Beaked Whale | Ecology |

Understanding cetacean species' distributions and population structure over space and time is necessary for effective conservation and management. Geographic differences in acoustic signals may provide a line of evidence for population-level discrimination in some cetacean species. We use acoustic recordings collected over broad spatial and temporal scales to investigate whether global variability in echolocation click peak frequency could elucidate population structure in Blainville's beaked whale (Mesoplodon densirostris), a cryptic species well-studied acoustically. …

View More

Odontocete spatial patterns and temporal drivers of detection at sites in the Hawaiian islands

Ziegenhorn, M. A. | Hildebrand, J. A. | Oleson, E. M. | Baird, R. W. | Wiggins, S. M. | Baumann-Pickering, S.

2023 Jan Passive Acoustics | Distribution | Ecology | Hawaii

Successful conservation and management of marine top predators rely on detailed documentation of spatiotemporal behavior. For cetacean species, this information is key to defining stocks, habitat use, and mitigating harmful interactions. Research focused on this goal is employing methodologies such as visual observations, tag data, and passive acoustic monitoring (PAM) data. However, many studies are temporally limited or focus on only one or few species. In this study, we make use of …

View More

Killer Whale (Orcinus orca) Pulsed Calls in the Eastern Canadian Arctic

Sportelli J. J. | Jones, J. M. | Frasier, K. E. | Westdal, K. H. | Ootoowak, A. J. | Higdon, J. W. | Hildebrand, J. A.

2022 Sep Passive Acoustics | Distribution | Arctic

Killer whales (Orcinus orca) produce a variety of acoustic signal types used for communication: clicks, whistles, and pulsed calls. Discrete pulsed calls are highly stereotyped, repetitive, and unique to individual pods found around the world. Discriminating amongst pod specific calls can help determine population structure in killer whales and is used to track pod movements around oceans. Killer whale presence in the Canadian Arctic has increased substantially, but we have limited understanding of their ecology, movements, and stock identity. Two autonomous passive acoustic monitoring (PAM) hydrophones were deployed in the waters of Eclipse Sound and Milne Inlet, in northern Baffin Island, Nunavut, Canada, in August and September 2017. Eleven killer whale pulsed call types …

View More

Rice’s whales in the northwestern Gulf of Mexico: call variation and occurrence beyond the known core habitat

Soldevilla, M. S. | Debich, A. J. | Garrison, L. P. | Hildebrand, J. A. | Wiggins, S. M.

2022 July Passive Acoustics | Rice's Whale | Distribution | Vocalization | Gulf of Mexico

The endangered Rice’s whale Balaenoptera ricei, with fewer than 100 individuals remaining, is the only year-round resident baleen whale found in the Gulf of Mexico (GOM) and occurs primarily along the northeastern shelf break near De Soto Canyon. Historical whaling records and predictive density modeling suggest that these whales…

View More

Acoustic localization, validation, and characterization of Rice’s whale calls

Soldevilla, M. S. | Ternus, K. | Cook, A. | Hildebrand, J. A. | Frasier, K. E. | Martinez, A. | Garrison, L. P.

2022 June Passive Acoustics | Rice's Whale | Call Repertoire | Localization | Vocalization | Gulf of Mexico

The recently named Rice’s whale in the Gulf of Mexico is one of the most endangered whales in the world, and improved knowledge of spatiotemporal occurrence patterns is needed to support their recovery and conservation. Passive acoustic monitoring methods for determining spatiotemporal occurrence patterns require identifying the…

View More

Echolocation repetition rate as a proxy to monitor population structure and dynamics of sperm whales

Solsona Berga, A. | Posdaljian. N. | Hildebrand, J. A. | Baumann-Pickering, S.

2022 June Acoustic Monitoring | Echolocation | Migration | Sperm Whale | Gulf of Mexico

Characterizing population structure and dynamics is critical for the conservation of endangered species. Monitoring sperm whales Physeter macrocephalus is especially difficult because it requires monitoring different latitudes to capture the dynamics of most populations. Since their remarkable sexual dimorphism in body size is reflected in…

View More

The influence of sea ice on the detection of bowhead whale calls

Jones, J. M. | Hildebrand, J. A. | Thayre, B. J. | Jameson, E. | Small, R. J. | Wiggins, S. M.

2022 May Passive Acoustics | Bowhead Whale | Sea Ice | Detection | Arctic

Bowhead whales (Balaena mysticetus) face threats from diminishing sea ice and increasing anthropogenic activities in the Arctic. Passive acoustic monitoring is the most effective means for monitoring their distribution and population trends, based on the detection of their calls. Passive acoustic monitoring, however, is influenced by…

View More

Modeling and Monitoring Submerged Prehistoric Sites during Offshore Sand Dredging and Implications for the Study of Early Holocene Coastal Occupation of Southern California

Hildebrand, J. A. | York, A. L.

2022 May Archaeology | California

Beach sand dredging projects off the coast of San Diego County in Southern California provide data for improved understanding of the strategraphic setting for early Holocene sediments and the potential for offshore presence of buried archaeological materials. Geophysical data, core sediments, and analysis of recovered fossils allowed…

View More

Echolocation click discrimination for three killer whale ecotypes in the Northeastern Pacific

Leu, A. A. | Hildebrand, J. A. | Rice, A. | Baumann-Pickering, S. | Frasier, K. E.

2022 May Passive Acoustics | Killer Whale | Vocalization | Echolocation | Northeast Pacific

Three killer whale ecotypes are found in the Northeastern Pacific: residents, transients, and offshores. These ecotypes can be discriminated in passive acoustic data based on distinct pulsed call repertoires. Killer whale acoustic encounters for which ecotypes were assigned based on pulsed call matching were used to characterize the…

View More

Discriminating and classifying odontocete echolocation clicks in the Hawaiian Islands using machine learning methods

Ziegenhorn, M. A. | Frasier, K. E. | Hildebrand, J. A. | Oleson, E. M. | Robin W. Baird | Wiggins, S. M. | Baumann-Pickering, S.

2022 April Passive Acoustics | Classification | Detection | Odontocete | Echolocation | Machine Learning | Hawaii

Passive acoustic monitoring (PAM) has proven a powerful tool for the study of marine mammals, allowing for documentation of biologically relevant factors such as movement patterns or animal behaviors while remaining largely non-invasive and cost effective. From 2008-2019, a set of PAM recordings covering the frequency band of most...

View More

Update on frequency decline of Northeast Pacific blue whale (Balaenoptera musculus) calls

Rice, A. | Širović, A. | Hildebrand, J. A. | Wood, M. | Carbaugh-Rutland, A. | Baumann-Pickering, S.

2022 April Passive Acoustics | Blue Whale | Vocalization | Call Abundance | California

Worldwide, the frequency (pitch) of blue whale (Balaenoptera musculus) calls has been decreasing since first recorded in the 1960s. This frequency decline occurs over annual and inter-annual timescales and has recently been documented in other baleen whale species, yet it remains unexplained. In the Northeast Pacific, blue whales…

View More

Identification of western North Atlantic odontocete echolocation click types using machine learning and spatiotemporal correlates

Cohen, R. E. | Frasier, K. E. | Baumann-Pickering, S. | Wiggins, S. M. | Rafter, M. A. | Baggett, L. M. | Hildebrand, J. A.

2022 March Identification | Odontocete | Echolocation | Machine Learning | Northwest Atlantic

A combination of machine learning and expert analyst review was used to detect odontocete echolocation clicks, identify dominant click types, and classify clicks in 32 years of acoustic data collected at 11 autonomous monitoring sites in the western North Atlantic between 2016 and 2019. Previously-described click types for eight known...

View More
View PDF

PLoS ONE | Vol. 17(3):e0264988 | DOI:10.1121/10.0009270

Changes in sea ice and range expansion of sperm whales in the eclipse sound region of Baffin Bay, Canada

Posdaljian. N. | Soderstjerna, C. | Jones, J. M. | Solsona Berga, A. | Hildebrand, J. A. | Westdal, K. H. | Ootoowak, A. J. | Baumann-Pickering, S.

2022 March Passive Acoustics | Sperm Whale | Sea Ice | Presence | Distribution | Climate Change | Arctic

Sperm whales (Physeter macrocephalus) are a cosmopolitan species but are only found in ice-free regions of the ocean. It is unknown how their distribution might change in regions undergoing rapid loss of sea ice and ocean warming like Baffin Bay in the eastern Canadian Arctic. In 2014 and 2018, sperm whales were sighted near...

View More

Performance metrics for marine mammal signal detection and classification

Hildebrand, J. A. | Frasier, K. E. | Helble, T. A. | Roch, M. A.

2022 January Classification | Detection | Automated Process

Automatic algorithms for the detection and classification of sound are essential to the analysis of acoustic datasets with long duration. Metrics are needed to assess the performance characteristics of these algorithms. Four metrics for performance evaluation are discussed here: receiver-operating-characteristic (ROC) curves...

View More

Beluga (Delphinapterus leucas) and narwhal (Monodon monoceros) echolocation click detection and differentiation from long-term Arctic acoustic recordings

Jones, J. M. | Frasier, K. E. | Westdal, K. H. | Ootoowak, A. J. | Wiggins, S. M. | Hildebrand, J. A.

2022 January Passive Acoustics | Echolocation | Classification | Beluga | Narwhal | Arctic

Beluga (Delphinapterus leucas) and narwhal (Mondon monoceros) echolocation signals have been described in numerous acoustic studies but reported characteristics of their clicks vary across studies. Here, a year of acoustic recordings was collected in the Chukchi Sea where belugas are abundant, and narwhals are not present...

View More

A machine learning pipeline for classification of cetacean echolocation clicks in large underwater acoustic dataset

Frasier, K. E.

2021 Dec Passive Acoustics | Machine Learning

Machine learning algorithms, including recent advances in deep learning, are promising for tools for detection and classification of broadband high frequency signals in passive acoustic recordings. However, these methods are generally data-hungry and progress has been limited by challenges related to the lack of labeled datasets adequate for training and testing. Large quantities of known and as yet unidentified broadband signal types mingle in marine recordings, with variability introduced by acoustic propagation, source depths and orientations, and interacting signals. …

View More

Long-Term Patterns of Noise From Underwater Explosions and Their Relation to Fisheries in Southern California

Krumpel, A. | Rice, A. | Frasier, K. E. | Reese, F. | Trickey, J. S. | Simonis, A. E. | Ryan, J.P. | Wiggins, S. M. | Denzinger, A. | Schnitzler, H. | Baumann-Pickering, S.

2021 December Long-Term Acoustic Monitoring | Explosions | Anthropogenic Noise | California

Acoustic deterrents can reduce marine mammal interactions with fisheries and aquacultures, but they contribute to an increasing level of underwater noise. In Southern California, commercially produced explosive deterrents, commonly known as “seal bombs,” are used to protect fishing gear and catch from pinniped predation, which can...

View More

The resonant acoustic signatures of lithic debitage

Morris, M. A. | Krysl, P. | Rivera-Collazo, I. C. | Hildebrand, J. A.

2021 December Underwater Archaeology | Sonar

Acoustic methods to search for submerged archaeological sites have shown that concentrations of knapped flint produce a visible acoustic response in chirp sonar profiles in a variety of geographical settings. Field tests and simulations have suggested that the submerged lithic signal is due to acoustic resonances of the flaked stone. We...

View More

Underwater noise mitigation in the Santa Barbara Channel through incentive-based vessel speed reduction

ZoBell, V. M. | Frasier, K. E. | Morten, J. A. | Hastings, S. P. | Peavey Reeves, L. E. | Wiggins, S. M. | Hildebrand, J. A.

2021 September Ship Noise | Anthropogenic Noise | California

Commercial shipping is the dominant source of low‑frequency noise in the ocean. It has been shown that the noise radiated by an individual vessel depends upon the vessel’s speed. This study quantified the reduction in source levels (SLs) and sound exposure levels (SELs) for ships participating in two variations of a vessel speed...

View More

Seal bomb explosion sound source characterization

Wiggins, S. M. | Krumpel, A. | Dorman, L. M. | Hildebrand, J. A. | Baumann-Pickering, S.

2021 September Explosions | Anthropogenic Noise

Small explosive charges, called seal bombs, used by commercial fisheries to deter marine mammals from depredation and accidental bycatch during fishing operations, produce high level sounds that may negatively impact nearby animals. Seal bombs were exploded underwater and recorded at various ranges with a calibrated...

View More

Monitoring the acoustic ecology of the shelf break of Georges Bank, Northwestern Atlantic Ocean: New approaches to visualizing complex acoustic data

Weiss, S. G. | Cholewiak, D. | Frasier, K. E. | Trickey, J. S. | Baumann-Pickering, S. | Hildebrand, J. A. | Van Parijs, S. M.

2021 August Passive Acoustics | Cetacean | Soundscape | Presence | Vocalization | Anthropogenic Noise

Within a soundscape, anthropogenic sound often dominates frequency ranges used by various species, leading to signal overlap and potential communication masking. The acoustic niche hypothesis predicts species will avoid competition by vocalizing at unique bandwidths. To evaluate the extent of anthropogenic overlap, it’s helpful...

View More

State of the California Current 2019-2020: Back to the Future With Marine Heatwaves?

Weber, E. D. | Auth, T. D. | Baumann-Pickering, S. | Baumgartner, T. R. | Bjorkstedt, E. P. | Bograd, S. J. | Burke, B. J. | Cadena-Ramírez, J. L. | Daly, E. A. | de la Cruz, M. | Dewar, H. | Field, J. C. | Fisher, J. L. | Giddings, A. | Goericke, R. | Gomez-Ocampo, E. | Gomez-Valdes, J. | Hazen, E. L. | Hildebrand, J. A. | Horton, C. A. | Jacobson, K. C. | Jacox, M. G. | Jahncke, J. | Kahru, M. | Kudela, R. M. | Lavaniegos, B. E. | Leising, A. | Melin, S. R. | Miranda-Bojorquez, L. E. | Morgan, C. A. | Nickels, C. F. | Orben, R. A. | Porquez, J. M. | Portner, E. J. | Robertson, R. R. | Rudnick, D. L. | Sakuma, K. M. | Santora, J. A. | Schroeder, I. D. | Snodgrass, O. E. | Sydeman, W. J. | Thompson, A. R. | Thompson, S. A. | Trickey, J. S. | Villegas-Mendoza, J. | Warzybok, P. | Watson, W. | Zeman, S. M.

2021 August Temperature | California

The California Current System (CCS) has experienced large fluctuations in environmental conditions in recent years that have dramatically affected the biological community. Here we synthesize remotely sensed, hydrographic, and biological survey data from throughout the CCS in 2019-2020 to evaluate how recent changes in...

View More

Cetacean occurrence offshore of Washington from long-term passive acoustic monitoring

Rice, A. | Debich, A. J. | Širović, A. | Oleson, E. M. | Trickey, J. S. | Varga, L. M. | Wiggins, S. M. | Hildebrand, J. A. | Baumann-Pickering, S.

2021 July Cetacean | Passive Acoustics | Presence | Washington

A variety of cetacean species inhabit the productive waters offshore of Washington State, USA. Although the general presence of many of these species has been documented in this region, our understanding of fine-scale habitat use is limited. Here, passive acoustic monitoring was used to investigate the spatial and temporal distributions...

View More

An empirical model for wind-generated ocean noise

Hildebrand, J. A. | Frasier, K. E. | Baumann-Pickering, S. | Wiggins, S. M.

2021 June Wind | Long-Term Acoustic Monitoring | Ambient Noise

An empirical model for wind-generated underwater noise is presented that was developed using an extensive dataset of acoustic field recordings and a global wind model. These data encompass more than one hundred years of recording-time and capture high wind events, and were collected both on shallow continental shelves...

View More

Using context to train time-domain echolocation click detectors

Roch, M. A. | Lindeneau, S. | Aurora, G. S. | Frasier, K. E. | Hildebrand, J. A. | Glotin, H. | Baumann-Pickering, S.

2021 May Echolocation | Detection | Machine Learning | Automated Process

This work demonstrates the effectiveness of using humans in the loop processes for constructing large training sets for machine learning tasks. A corpus of over 57 000 toothed whale echolocation clicks was developed by using a permissive energy-based echolocation detector followed by a machine-assisted quality control process...

View More

Cetacean occurrence in the Gulf of Alaska from long‑term passive acoustic monitoring

Rice, A. | Širović, A. | Trickey, J. S. | Debich, A. J. | Gottlieb, R. S. | Wiggins, S. M. | Hildebrand, J. A. | Baumann-Pickering, S.

2021 April Cetacean | Long-Term Acoustic Monitoring | Distribution | Gulf of Alaska

The Gulf of Alaska is an important habitat for a diverse array of marine mammals, many of which were severely depleted by historical whaling. To study current cetacean distributions in this region, passive acoustic monitoring was used to detect species-specific call types between 2011 and 2015 at five locations spanning the...

View More

Cetacean distribution models based on visual and passive acoustic data

Frasier, K. E. | Garrison, L. P. | Soldevilla, M. S. | Wiggins, S. M. | Hildebrand, J. A.

2021 April Cetacean | Passive Acoustics | Visual Survey Distribution | Gulf of Mexico

Distribution models are needed to understand spatiotemporal patterns in cetacean occurrence and to mitigate anthropogenic impacts. Shipboard line-transect visual surveys are the standard method for estimating abundance and describing the distributions of cetacean populations. Ship-board surveys provide high spatial resolution but lack…

View More

Timing is everything: Drivers of interannual variability in blue whale migration

Szesciorka, A. R. | Balance, L. T. | Širović, A. | Rice, A. | Ohman, M. D. | Hildebrand, J. A. | Franks, P. J. S.

2020 May Blue Whale | Migration | Temperature | California

Blue whales need to time their migration from their breeding grounds to their feeding grounds to avoid missing peak prey abundances, but the cues they use for this are unknown. We examine migration timing (inferred from the local onset and cessation of blue whale calls recorded on seafloor-mounted hydrophones), environmental...

View More

DetEdit: A graphical user interface for annotating and editing events detected in long-term acoustic monitoring data

Solsona Berga, A. | Frasier, K. E. | Baumann-Pickering, S. | Wiggins, S. M. | Hildebrand, J. A.

2020 January Passive Acoustics | Long-Term Acoustic Monitoring | Automated Process | Classification

Passive acoustic monitoring has become an important data collection method, yielding massive datasets replete with biological, environmental and anthropogenic information. Automated signal detectors and classifiers are needed to identify events within these datasets, such as the presence of species-specific sounds or anthropogenic...

View More

Fin whale 40-Hz calling behavior studied with an acoustic tracking array

Wiggins, S. M. | Hildebrand, J. A.

2020 February Fin Whale | Vocalization | Acoustic Behavior | Three Dimensional Acoustic Tracking

Fin whales (Balaenoptera physalus), the second largest baleen whale and an endangered species, occur worldwide and are found in all major oceans (Reilly et al., 2013). Fin whales produce two main types of stereotypical, frequency downswept, high-amplitude, short duration (<1 s) calls, that are known by their primary frequencies as…

View More

Co-occurrence of beaked whale strandings and naval sonar in the Mariana Islands, Western Pacific

Simonis, A. E. | Brownell, R. L. | Thayre, B. J. | Trickey, J. S. | Oleson, E. M. | Huntington, R. | Baumann-Pickering, S.

2020 February Beaked Whale | Ecology | Sonar | Stranding Event | Mariana Islands

Mid-frequency active sonar (MFAS), used for antisubmarine warfare (ASW), has been associated with multiple beaked whale (BW) mass stranding events. Multinational naval ASW exercises have used MFAS offshore of the Mariana Archipelago semi-annually since 2006. We report BW and MFAS acoustic activity near the islands of Saipan...

View More

Migrating eastern North Pacific gray whale call and blow rates estimated from acoustic recordings, infrared camera video, and visual sightings

Guazzo, R. A. | Weller, D. W. | Europe, H. M. | Durban, J. W. | D’Spain, G. L. | Hildebrand, J. A.

2019 August Gray Whale | Migration | Call Abundance | Acoustic Monitoring | Visual Survey

During the eastern North Pacific gray whale 2014-2015 southbound migration, acoustic call recordings, infrared blow detections, and visual sightings were combined to estimate cue rates, needed to convert detections into abundance. The gray whale acoustic call rate ranged from 2.3-24 calls/whale/day during the peak of the southbound...

View More

Gray whale migration patterns through the Southern California Bight from multi-year visual and acoustic monitoring

Guazzo, R. A. | Schulman-Janiger, A. | Smith, M. H. | Barlow, J. P. | D’Spain, G. L. | Rimington, D. B. | Hildebrand, J. A.

2019 August Gray Whale | Acoustic Monitoring | Visual Survey | Migration | Sea Ice | Temperature | California

Sightings and acoustic recordings from eastern North Pacific gray whales in the Southern California Bight were analyzed for interannual changes and compared with concurrent environmental measurements during 7 migration seasons (2008-2009 to 2014-2015). Acoustic call counts recorded on an offshore hydrophone were highly variable...

View More

Assessing seasonality and density from passive acoustic monitoring of signals presumed to be from pygmy and dwarf sperm whales in the Gulf of Mexico

Hildebrand, J. A. | Frasier, K. E. | Baumann-Pickering, S. | Wiggins, S. M. | Merkens, K. P. | Garrison, L. P. | Soldevilla, M. S. | Mcdonald, M. A.

2019 February Seasonality | Density | Passive Acoustics | Sperm Whale | Gulf of Mexico

Pygmy sperm whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) are deep diving cetaceans that commonly strand along the coast of the southeast US, but that are difficult to study visually at sea because of their elusive behavior. Conventional visual surveys are thought to significantly underestimate the presence of Kogia and...

View More

Evaluating impacts of deep oil spills on oceanic marine mammals

Frasier, K. E.

2019 July Passive Acoustics | Deepwater Horizon Oil Spill | Gulf of Mexico

The Deepwater Horizon (DWH) oil spill may be indicative of future large, deep spills that may occur in the coming decades. Given that future deepwater spills are possible, critical considerations include (1) establishing baselines for oceanic marine mammal and populations in at-risk areas, (2) understanding the implications of response...

View More

Impacts of the Deepwater Horizon oil spill on marine mammals and sea turtles

Frasier, K. E. | Solsona Berga, A. | Stokes, L. | Hildebrand, J. A.

2019 June Passive Acoustics | Deepwater Horizon Oil Spill | Gulf of Mexico

The Gulf of Mexico (GOM) is one of the most diverse ecosystems in the world (Fautin et al. PLoS One 5(8):e11914, 2010). Twenty-one species of marine mammals and five species of sea turtles were routinely identified in the region by the end of the twenty-first century (Waring et al. NOAA Tech Memo NMFS NE 231:361, 2015)...

View More

A description of echolocation clicks recorded in the presence of True’s beaked whale (Mesoplodon mirus)

Deangelis, A. I. | Stanistreet, J. E. | Baumann-Pickering, S. | Cholewiak, D. M.

2018 November Echolocation | Beaked Whale

True's beaked whales (Mesoplodon mirus) were encountered on two separate shipboard surveys on 24 July 2016 and 16 September 2017 in the western North Atlantic Ocean. Recordings were made using a hydrophone array towed 300 m behind the ship. In 2016, three different groups were sighted within 1500 m of the ship; clicks were...

View More

Seismic airgun sound propagation in Arctic Ocean waveguides

Keen, K. A. | Thayre, B. J. | Hildebrand, J. A. | Wiggins, S. M.

2018 September Airguns | Anthropogenic Noise | Sound Propagation | Arctic

Underwater recordings of seismic airgun surveys in the deep-water Beaufort Sea and on the shallow-water Chukchi Sea shelf were made from sites on the continental slope and shelf break north-northwest of Point Barrow, Alaska. Airgun pulses from the deep-water survey were recorded more than 500 km away, and from the shallow-water...

View More

Heard but not seen: Occurrence of Kogia spp. along the western North Atlantic shelf break

Hodge, L. E. W. | Baumann-Pickering, S. | Hildebrand, J. A. | Bell, J. T. | Cummings, E. W. | Foley, H. J. | Mcalarney, R. J. | Mclellan, W. A. | Pabst, D. A. | Swaim, Z. T. | Waples, D. M. | Read, A. J.

2018 March Acoustic Monitoring | Sperm Whale | Northwest Atlantic

The two species in the family Kogiidae, the pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales, are found worldwide in tropical and temperate waters (Jefferson et al. 1993). These cryptic species (hereafter referred to as Kogia) are difficult to detect during visual surveys due to their small size and inconspicuous surfacing behavior...

View More

Behavior of singing fin whales Balaenoptera physalus tracked acoustically offshore of Southern California

Varga, L. M. | Wiggins, S. M. | Hildebrand, J. A.

2018 March Acoustic Behavior | Vocalization | Three Dimensional Acoustic Tracking | Fin Whale | California

Fin whales Balaenoptera physalus produce stereotyped low-frequency calls (15-30 Hz) that can be detected at great ranges and are considered song when produced in a repeated temporal pattern. These calls, referred to as 20 Hz calls, were localized and tracked using a 1 km aperture array of 4 passive acoustic recorders at...

View More

Spatial and seasonal patterns in acoustic detections of sperm whales Physeter macrocephalus along the continental slope in the western North Atlantic Ocean

Stanistreet, J. E. | Nowacek, D. P. | Bell, J. T. | Cholewiak, D. M. | Hildebrand, J. A. | Hodge, L. E. W. | Van Parijs, S. M. | Read, A. J.

2018 January Seasonality | Distribution | Acoustic Monitoring | Detection | Sperm Whale | Northwest Atlantic

The distribution and seasonal movements of sperm whales Physeter macrocephalus are poorly understood in the western North Atlantic Ocean, despite a long history of human exploitation of the species. Cetacean surveys in this region are typically conducted during the summer, when weather conditions are amenable for visual observation...

View More

Automated classification of dolphin echolocation click types from the Gulf of Mexico

Frasier, K. E. | Roch, M. A. | Soldevilla, M. S. | Garrison, L. P. | Hildebrand, J. A.

2017 December Classification | Automated Process | Echolocation | Delphinid | Gulf of Mexico

Delphinids produce large numbers of short duration, broadband echolocation clicks which may be useful for species classification in passive acoustic monitoring efforts. A challenge in echolocation click classification is to overcome the many sources of variability to recognize underlying patterns across many detections. An automated…

View More

Migratory behavior of eastern North Pacific gray whales tracked using a hydrophone array

Guazzo, R. A. | Helble, T. A. | D’Spain, G. L. | Weller, D. W. | Wiggins, S. M. | Hildebrand, J. A.

2017 October Migration | Gray Whale | Three Dimensional Acoustic Tracking

Eastern North Pacific gray whales make one of the longest annual migrations of any mammal, traveling from their summer feeding areas in the Bering and Chukchi Seas to their wintering areas in the lagoons of Baja California, Mexico. Although a significant body of knowledge on gray whale biology and behavior exists, little is known about…

View More

Long-term passive acoustic recordings track the changing distribution of North Atlantic right whales (Eubalaena glacialis) from 2004 to 2014

Davis, G. E. | Baumgartner, M. F. | Bonnell, J. M. | Bell, J. | Berchok, C. | Bort Thornton, J. | Brault, S. | Buchanan, G. | Charif, R. A. | Cholewiak, D. M. | Clark, C. W. | Corkeron, P. | Delarue, J. | Dudzinski, K. | Hatch, L. | Hildebrand, J. A. | Hodge, L. E. W. | Klinck, H. | Kraus, S. | Martin, B. | Mellinger, D. K. | Moors-Murphy, H. | Nieukirk, S. | Nowacek, D. P. | Parks, S. | Read, A. J. | Rice, A. N. | Risch, D. | Širović, A. | Soldevilla, M. | Stafford, K. | Stanistreet, J. E. | Summers, E. | Todd, S. | Warde, A. | Van Parijs, S. M.

2017 October Distribution | Long Term Acoustic Monitoring | North Atlantic Right Whale

Given new distribution patterns of the endangered North Atlantic right whale (NARW; Eubalaena glacialis) population in recent years, an improved understanding of spatio-temporal movements are imperative for the conservation of this species. While so far visual data have provided most information on NARW movements, passive…

View More

Deep-water measurements of container ship radiated noise signatures and directionality

Gassmann, M. | Wiggins, S. M. | Hildebrand, J. A.

2017 September Ship Noise

Underwater radiated noise from merchant ships was measured opportunistically from multiple spatial aspects to estimate signature source levels and directionality. Transiting ships were tracked via the Automatic Identification System in a shipping lane while acoustic pressure was measured at the ships' keel and beam aspects. Port…

View More

Fin whale song variability in Southern California and the Gulf of California

Širović, A. | Oleson, E. M. | Buccowich, J. | Rice, A. | Bayless, A. R.

2017 August Vocalization | Fin Whale | California | Gulf of California

Songs are distinct, patterned sounds produced by a variety of animals including baleen whales. Fin whale songs, which consist of short pulses repeated at regular interpulse intervals (IPIs), have been suggested as a tool to distinguish populations. Fin whale songs were analyzed from data collected from 2000-2012 in Southern California…

View More

Lunar cycles affect common dolphin Delphinus delphis foraging in the Southern California Bight

Simonis, A. E. | Roch, M. A. | Bailey, B. | Barlow, J. P. | Clemesha, R. E. S. | Iacobellis, S. | Hildebrand, J. A. | Baumann-Pickering, S.

2017 August Lunar Cycle | Echolocation | Foraging | Common Dolphin | California

In the Southern California Bight, the common dolphin Delphinus delphis is the most abundant dolphin species and preys upon small pelagic fish, mesopelagic fish, and cephalopods. Mesopelagic fish and many cephalopods are available throughout the year, and they form deep scattering layers, some of which characteristically...

View More

High-frequency modulated signals recorded off the Antarctic Peninsula area: are killer whales emitting them?

Reyes Reyes, M. V. | Baumann-Pickering, S. | Simonis, A. E. | Melcon, M. L. | Trickey, J. S. | Hildebrand, J. A. | Iniguez, M. A.

2017 August High-Frequency | Killer Whale | Antarctica

High-frequency modulated signals with a stereotyped down-swept contour were recorded in the northwestern Antarctic Peninsula using an autonomous recorder and a towed hydrophone array. Signals have a mean start frequency at 21.6 kHz, end frequency at 15.7 kHz, -10 dB bandwidth of 5.9 kHz, and duration of 65.2 ms. Bouts of…

View More

Spatial distribution and dive behavior of Gulf of Mexico Bryde’s whales: potential risk of vessel strikes and fisheries interactions

Soldevilla, M. S. | Hildebrand, J. A. | Frasier, K. E. | Aichinger Dias, L. | Martinez, A. | Mullin, K. D. | Rosel, P. E. | Garrison, L. P.

2017 June Distribution | Dive Behavior | Fisheries Interactions | Vessel Strikes | Bryde’s Whale | Gulf of Mexico

Bryde’s whales Balaenoptera edeni are the only resident baleen whale species in the Gulf of Mexico (GoM), where they are extremely rare, have a restricted distribution, and represent a unique evolutionary lineage. The reasons for the restricted distribution and small population size are unknown, but high levels of industrial activity in the…

View More

Spatial and temporal occurrence of killer whale ecotypes off the outer coast of Washington State, USA

Rice, A. | Deecke, V. B. | Ford, J. K. B. | Pilkington, J. F. | Oleson, E. M. | Hildebrand, J. A. | Širović, A.

2017 May Spatio-Temporal | Killer Whale | Washington

Three killer whale Orcinus orca ecotypes inhabit the northeastern Pacific: residents, transients, and offshores. To investigate intraspecific differences in spatial and temporal occurrence off the outer coast of Washington State, USA, 2 long-term acoustic recorders were deployed from July 2004 to August 2013: one off the continental shelf…

View More

Habitat-based density models for three cetacean species off southern California illustrate pronounced seasonal differences

Becker, E. A. | Forney, K. A. | Thayre, B. J. | Simonis A. E. | Debich, A. J. | Campbell, G. S. | Whitaker, K. | Douglas, A. B. | Gilles, A. | Hoopes, R. | Hildebrand, J. A.

2017 May Density | Cetacean | Seasonality | California

Managing marine species effectively requires spatially and temporally explicit knowledge of their density and distribution. Habitat-based density models, a type of species distribution model (SDM) that uses habitat covariates to estimate species density and distribution patterns, are increasingly used for marine management and…

View More

Using passive acoustic monitoring to document the distribution of beaked whale species in the western North Atlantic Ocean

Stanistreet, J. E. | Nowacek, D. P. | Baumann-Pickering, S. | Bell, J. T. | Cholewiak, D. M. | Hildebrand, J. A. | Hodge, L. E. W. | Moors-Murphy, H. B. | Van Parijs, S. M. | Read, A. J.

2017 February Distribution | Acoustic Monitoring | Beaked Whale | Northwest Atlantic

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…

View More

Acoustically monitoring the Hawai‘i longline fishery for interactions with false killer whales

Bayless, A. R. | Oleson, E. M. | Baumann-Pickering, S. | Simonis, A. E. | Marchetti, J. | Martin, S. | Wiggins, S. M.

2017 February Acoustic Monitoring | False Killer Whale | Fisheries Interactions | Hawaii

False killer whales (Pseudorca crassidens) feed primarily on several species of large pelagic fish, species that are also targeted by the Hawai‘i-permitted commercial deep-set longline fishery. False killer whales have been known to approach fishing lines in an attempt to procure bait or catch from the lines, a behavior known as depredation…

View More

Seasonal acoustic behavior of blue whales (Balaenoptera musculus) in the Gulf of California, Mexico

Paniagua-Mendoza, A. | Gendron, D. | Romero-Vivas, E. | Hildebrand, J. A.

2016 December Acoustic Behavior | Seasonality | Blue Whale | Gulf of California

Six years of passive acoustic monitoring data from the Gulf of California reveal seasonality and movements for the northeastern Pacific blue whales. Three sites were studied, one from the southern (Punta Pescadero) and two from the northern (Isla Tiburon and Canal de Ballenas) regions. A total of 4,953 h were analyzed, and 15,539 blue…

View More

Delphinid echolocation click detection probability on near-seafloor sensors

Frasier, K. E. | Wiggins, S. M. | Harris, D. | Marques, T. A. | Thomas, L. | Hildebrand, J. A.

2016 September Delphinid | Echolocation | Detection | Gulf of Mexico

The probability of detecting echolocating delphinids on a near-seafloor sensor was estimated using two Monte Carlo simulation methods. One method estimated the probability of detecting a single click (cue counting); the other estimated the probability of detecting a group of delphinids (group counting). Echolocation click beam pattern and…

View More

Gulf of Mexico low-frequency ocean soundscape impacted by airguns

Wiggins, S. M. | Hall, J. M. | Thayre, B. J. | Hildebrand, J. A.

2016 July Low-Frequency | Soundscape | Airguns | Gulf of Mexico

The ocean soundscape of the Gulf of Mexico (GOM) has not been well-studied, although it is an important habitat for marine mammals, including sperm and beaked whales, many dolphin species, and a potentially endangered baleen whale species. The GOM is also home to high levels of hydrocarbon exploration and extraction, heavily…

View More

Effects of duty-cycled passive acoustic recordings on detecting the presence of beaked whales in the northwest Atlantic

Stanistreet, J. E. | Nowacek, D. P. | Read, A. J. | Baumann-Pickering, S. | Moors-Murphy, H. B. | Van Parijs, S. M.

2016 July Passive Acoustics | Detection | Presence | Beaked Whale | Northwest Atlantic

This study investigated the effects of using duty-cycled passive acoustic recordings to monitor the daily presence of beaked whale species at three locations in the northwest Atlantic. Continuous acoustic records were subsampled to simulate duty cycles of 50%, 25%, and 10% and cycle period durations from 10 to 60 min. Short, frequent…

View More

Communication sounds of Commerson’s dolphins (Cephalorhynchus commersonii) and contextual use of vocalizations

Reyes Reyes, M. V. | Tossenberger, V. P. | Iniguez, M. A. | Hildebrand, J. A. | Melcón, M. L.

2016 May Communication | Vocalization | Acoustic Behavior | Commerson's Dolphin

Cetaceans produce a variety of vocalizations to communicate; however, little information exists on the acoustic behavior displayed by Commerson's dolphins (Cephalorhynchus commersonii) in the wild other than their echolocation behavior. Most available literature suggests that Commerson's dolphins do not produce any other sound type…

View More

Ocean ambient sound south of Bermuda and Panama Canal traffic

Širović, A. | Hildebrand, J. A. | McDonald, M. A.

2016 May Ambient Noise | Ocean Traffic | Bermuda | Panama Canal

Comparisons of current and historic ocean ambient noise levels are rare, especially in the North Atlantic. Recent (2013-2014) monthly patterns in ocean ambient sound south of Bermuda were compared to those recorded at the same location in 1966. Additionally, trends in ocean traffic, in particular, Panama Canal traffic, over this time were…

View More

Automated identification and clustering of subunits within delphinid vocalizations

Frasier, K. E. | Henderson, E. E. | Bassett, H. R. | Roch, M. A.

2016 February Classification | Automated Process | Communication | Vocalization | Delphinid | Dynamic Time Warping | Network Analysis

Tonal vocalizations or whistles produced by many species of delphinids range from simple tones to complex frequency contours. Whistle structure varies in duration, frequency, and composition between delphinid species, as well as between populations and individuals. Categorization of whistles may be improved by decomposition of…

View More

Odontocete occurrence in relation to changes in oceanography at a remote equatorial Pacific seamount

Baumann-Pickering, S. | Trickey, J. S. | Wiggins, S. M. | Oleson, E. M.

2016 January Odontocetes | Long-Term Acoustic Monitoring | Passive Acoustics | Ecology | Beaked Whale | Dolphin | Seamount

Seamounts are considered hot spots of biodiversity and can aggregate pelagic predators and their prey. Passive acoustic monitoring was conducted over 3 mo in 2012 to document the occurrence of odontocetes near a seamount chain in the central equatorial Pacific in relation to oceanographic changes over time. Beaked whale…

View More

Seasonality of Antarctic minke whale (Balaenoptera bonaerensis) calls off the western Antarctic Peninsula

Dominello, T. | Širović, A.

2016 January Seasonality | Vocalization | Minke Whale | Antarctica

The Antarctic minke whale (Balaenoptera bonaerensis) is a difficult species to study because of its low visual detectability and preference for living within the sea ice habitat, accessible only by ice-strengthened vessels. Recent identification of the Antarctic minke whale as the source of the seasonally ubiquitous bio-duck call has allowed…

View More

Long-term monitoring of cetaceans using autonomous acoustic recording packages

Wiggins, S. M. | Hildebrand, J. A.

2016 February Long-Term Acoustic Monitoring | Cetacean | Autonomous Acoustic Recording

Autonomous acoustic recorders have advanced our understanding of cetaceans, providing information for better models of species distribution, behavior, ecology, and conservation. For over a decade, Acoustic Recording Packages (ARPs), and its broader-bandwidth successor, High-frequency Acoustic Recording Package…

View More

State Of The California Current 2015 - 16: Comparisons With The 1997 - 98 El Niño

Debich, A. J. | Hildebrand, J. A. | et al.

2016 California | El Niño

Warm conditions in the North Pacific in 2014-15 were a result of the continuation of the North Pacific marine heat wave, a large area of exceptionally high SST anomalies that originated in the Gulf of Alaska in late 2013. The North Pacific heat wave interacted with an El Niño developing in the equatorial Pacific in 2015. Weekly periods of…

View More
View PDF

CalCOFI Report | Vol. 57:1-57

Passive acoustic monitoring of beaked whale densities in the Gulf of Mexico

Hildebrand, J. A. | Baumann-Pickering, S. | Frasier, K. E. | Trickey, J. S. | Merkens, K. P. | Wiggins, S. M. | McDonald, M. A. | Garrison, L. P. | Harris, D. | Marques, T. A. | Thomas, L.

2015 November Passive Acoustics | Beaked Whale | Density | Gulf of Mexico

Beaked whales are deep diving elusive animals, difficult to census with conventional visual surveys. Methods are presented for the density estimation of beaked whales, using passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period during and following the Deepwater Horizon oil spill (2010-2013)…

View More

Three-dimensional tracking of Cuvier’s beaked whales’ echolocation sounds using nested hydrophone arrays

Gassmann, M. | Wiggins, S. M. | Hildebrand, J. A.

2015 October Three Dimensional Acoustic Tracking | Beaked Whale | Echolocation

Cuvier's beaked whales (Ziphius cavirostris) were tracked using two volumetric small-aperture (∼1 m element spacing) hydrophone arrays, embedded into a large-aperture (∼1 km element spacing) seafloor hydrophone array of five nodes. This array design can reduce the minimum number of nodes that are needed to record the arrival…

View More

Description and clustering of echolocation signals of Commerson's dolphins (Cephalorhynchus commersonii) in Bahía San Julián, Argentina

Reyes Reyes, M. V. | Iñíguez, M. A. | Hevia, M. | Hildebrand, J. A. | Melcón, M. L.

2015 October Echolocation | Common Dolphin | Argentina

Commerson’s dolphins (Cephalorhynchus commersonii) inhabit coastal waters of Southern South America and Kerguelen Islands. Limited information exists about the acoustic repertoire of this species in the wild. Here, echolocation signals from free-ranging Commerson's dolphins were recorded in Bahía San Julián, Argentina. Signal…

View More

Acoustic behavior of melon-headed whales varies on a diel cycle

Baumann-Pickering, S. | Roch, M. A. | Wiggins, S. M. | Schnitzler, H. U. | Hildebrand, J. A.

2015 July Adaptive Acoustic Behavior | Ambient Noise | Echolocation | Melon-Headed Whale | Diel pattern

Many terrestrial and marine species have a diel activity pattern, and their acoustic signaling follows their current behavioral state. Whistles and echolocation clicks on long-term recordings produced by melon-headed whales (Peponocephala electra) at Palmyra Atoll indicated that these signals were used selectively during different phases…

View More

False killer whale and short-finned pilot whale acoustic identification

Baumann-Pickering, S. | Simonis, A. E. | Oleson, E. M. | Baird, R. W. | Roch, M. A. | Wiggins, S. M.

2015 July False Killer Whale | Short Finned Pilot Whale | Passive Acoustics | Echolocation | Classification | Identification

False killer whales Pseudorca crassidens and short-finned pilot whales Globicephala macrorhynchus are known to interact with long-line fishing gear in Hawaiian waters, causing economic loss and leading to whale injuries and deaths. The main Hawaiian Islands’ insular population of false killer whales is listed as endangered and the offshore…

View More

Seven years of blue and fin whale call abundance in the Southern California Bight

Širović, A. | Rice, A. | Chou, E. | Hildebrand, J. A. | Wiggins, S. M. | Roch, M. A.

2015 June Blue Whale | Fin Whale | Call Abundance | California

Blue whales Balaenoptera musculus and fin whales B. physalus are common inhabitants of the Southern California Bight (SCB), but little is known about the spatial and temporal variability of their use of this area. To study their distribution in the SCB, high-frequency acoustic recording packages were intermittently deployed at 16 locations…

View More

Antarctic beaked whale echolocation signals near South Scotia Ridge

Trickey, J. S. | Baumann-Pickering, S. | Hildebrand, J. A. | Reyes Reyes, M. V. | Melcón, M. L. | Iniguez, M. A.

2015 April Beaked Whale | Echolocation | Antarctica

Although beaked whales comprise the second-largest family of cetaceans, they are one of the most poorly known groups of all large mammals (Barlow et al. 2006, Jefferson et al. 2008). Visual sightings and species identification of beaked whales can be extremely difficult due to their highly elusive behavior and prolonged, deep foraging…

View More

Long-term acoustic monitoring at North Sea well site 22/4b

Wiggins, S. M. | Leifer, I. | Linke, P. | Hildebrand, J. A.

2015 February Long-Term Acoustic Monitoring | Marine Seep | Methane | Bubble Plume | North Sea

Marine seeps produce underwater sounds as a result of bubble formation and fragmentation upon emission from the seabed. The frequency content and sound levels of these emissions are related to bubble size distribution and emission flux, providing important information on methane release from the seafloor. Long-term passive…

View More

Compensating for the effects of site and equipment variation on delphinid species identification from their echolocation clicks

Roch, M. A. | Stinner-Sloan, J. | Baumann-Pickering, S. | Wiggins, S. M.

2015 January Variation | Delphinid | Identification | Echolocation

A concern for applications of machine learning techniques to bioacoustics is whether or not classifiers learn the categories for which they were trained. Unfortunately, information such as characteristics of specific recording equipment or noise environments can also be learned. This question is examined in the context of identifying delphinid…

View More

Synchronous Seasonal Change in Fin Whale Song in the North Pacific

Oleson, E. M. | Širović, A. | Bayless, A. R. | Hildebrand, J. A.

2014 December Seasonality | Fin Whale | Vocalization | North Pacific

Fin whale (Balaenoptera physalus) song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus) and humpback whales (Megaptera novaeangliae), these song sequences may be geographically distinct and may…

View More

North Pacific right whales (Eubalaena japonica) recorded in the Northeastern Pacific Ocean in 2013

Širović, A. | Johnson, S. C. | Roche, L. K. | Varga, L. M. | Wiggins, S. M. | Hildebrand, J. A.

2014 December North Pacific Right Whale | Northeast Pacific

The North Pacific right whale (Eubalaena japonica) is among the most critically endangered marine mammals in the world (Brownell et al. 2001). Its population was drastically reduced by 19th and 20th century whaling and its recovery was additionally slowed by illegal Soviet whaling that occurred during the 1960s (Clapham et al. 2004…

View More

Inter-annual and seasonal trends in cetacean distribution, density and abundance in waters off southern California

Campbell, G. S. | Thomas, L. | Whitaker, K. | Douglas, A. B. | Calambokidis, J. | Hildebrand, J. A.

2014 October Cetacean | Seasonality | Density | Abundance | Distribution | California

Trends in cetacean density and distribution off southern California were assessed through visual line-transect surveys during thirty-seven California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises from July 2004-November 2013. From sightings of the six most commonly encountered cetacean species, seasonal, annual and…

View More

Delphinid behavioral responses to incidental mid-frequency active sonar

Henderson, E. E. | Smith, M. H. | Gassmann, M. | Wiggins, S. M. | Douglas, A. B. | Hildebrand, J. A.

2014 October Delphinid | Anthropogenic Noise | Sonar | California

Opportunistic observations of behavioral responses by delphinids to incidental mid-frequency active (MFA) sonar were recorded in the Southern California Bight from 2004 through 2008 using visual focal follows, static hydrophones, and autonomous recorders. Sound pressure levels were calculated between 2 and 8 kHz. Surface…

View More

Ringed, Bearded, and Ribbon Seal Vocalizations North of Barrow, Alaska: Seasonal Presence and Relationship with Sea Ice

Jones, J. M. | Thayre, B. J. | Roth, E. H. | Mahoney, M. | Sia. I. | Merculief, K. | Jackson, C. | Zeller, C. | Clare, M. | Bacon, A. | Weaver, S. | Gentes, Z. | Stirling, I. | Wiggins, S. M. | Hildebrand, J. A.

2014 May Arctic Seals | Call Repertoire | Seasonality | Vocalization | Sea Ice | Alaska

The acoustic repertoires of ringed, bearded, and ribbon seals are described, along with their seasonal occurrence and relationship to sea ice concentration. Acoustic recordings were made between September and June over three years (2006 - 09) along the continental slope break in the Chukchi Sea, 120 km north-northwest of Barrow…

View More
View PDF

Arctic | Vol. 67(2):203-222 | DOI:10.14430/arctic4388

Seasonal distribution and abundance of cetaceans off Southern California estimated from CalCOFI cruise data from 2004 to 2008

Douglas, A. B. | Calambokidis, J. | Munger, L. M. | Soldevilla, M. S. | Ferguson, M. C. | Havron, A. M. | Camacho, D. L. | Campbell, G. S. | Hildebrand, J. A.

2014 May Seasonality | Distribution | Abundance | Cetacean | California

Documenting year-round diversity and distribution of marine mammals off Southern California is important for assessment of effects of potentially harmful anthropogenic activities. Although the waters off Southern California have been surveyed extensively for marine mammals over the past 18 years, such surveys have been periodic and were…

View More

Effects of fluctuations in sea-surface temperature on the occurrence of small cetaceans off Southern California

Henderson, E. E. | Forney, K. A. | Barlow, J. P. | Hildebrand, J. A. | Douglas, A. B. | Calambokidis, J. | Sydeman, W. J.

2014 March Temperature | Cetacean | California

The link between ocean temperature and spatial and temporal distribution patterns of 8 species of small cetaceans off Southern California was examined during the period 1979-2009. Averages and anomalies of sea-surface temperatures (SSTs) were used as proxies for SST fluctuations on 3 temporal scales: seasonal, El Niño-Southern…

View More

Spatio-Temporal Patterns of Beaked Whale Echolocation Signals in the North Pacific

Baumann-Pickering, S. | Roch, M. A. | Brownell Jr, R. L. | Simonis, A. E. | McDonald, M. A. | Solsona Berga, A. | Oleson, E. M. | Wiggins, S. M. | Hildebrand, J. A.

2014 January Spatio-Temporal | Beaked Whale | Echolocation | North Pacific

At least ten species of beaked whales inhabit the North Pacific, but little is known about their abundance, ecology, and behavior, as they are elusive and difficult to distinguish visually at sea. Six of these species produce known species-specific frequency modulated (FM) echolocation pulses: Baird’s, Blainville’s, Cuvier’s, Deraniyagala’s…

View More

Offshore killer whale tracking using multiple hydrophone arrays

Gassmann, M. | Henderson, E. E. | Wiggins, S. M. | Roch, M. A. | Hildebrand, J. A.

2013 December Killer Whale | Acoustic Monitoring | Three-Dimensional Acoustic Tracking

To study delphinid near surface movements and behavior, two L-shaped hydrophone arrays and one vertical hydrophone line array were deployed at shallow depths (<125 m) from the floating instrument platform R/P FLIP, moored northwest of San Clemente Island in the Southern California Bight. A three-dimensional propagation-model…

View More

Description of sounds associated with Sowerby’s beaked whales (Mesoplodon bidens) in the western North Atlantic Ocean

Cholewiak, D. M. | Baumann-Pickering, S. | Van Parijs, S. M.

2013 December Call Repertoire | Beaked Whale | Northwest Atlantic

Several groups of Sowerby's beaked whales (Mesoplodon bidens) were encountered on July 4, 2011, during a shipboard cetacean survey conducted off the eastern seaboard of the United States. Acoustic recordings were collected using a three-element towed hydrophone array. Many echolocation clicks were recorded during the encounter…

View More

Calibrating passive acoustic monitoring: Correcting humpback whale call detections for site-specific and time-dependent environmental characteristics

Helble, T. A. | D'Spain, G. L. | Campbell, G. S. | Hildebrand, J. A.

2013 October Calibration | Humback Whale | Detection | Spatio-Temporal

This paper demonstrates the importance of accounting for environmental effects on passive underwater acoustic monitoring results. The situation considered is the reduction in shipping off the California coast between 2008-2010 due to the recession and environmental legislation. The resulting variations in ocean noise change the…

View More

Ocean noise in the tropical and subtropical Pacific Ocean

Širović, A. | Wiggins, S. M. | Oleson, E. M.

2013 October Ambient Noise

Ocean ambient noise is well studied in the North Pacific and North Atlantic but is poorly described for most of the worlds' oceans. Calibrated passive acoustic recordings were collected during 2009-2010 at seven locations in the central and western tropical and subtropical Pacific. Monthly and hourly mean power spectra (15-1000 Hz)…

View More

Species-specific beaked whale echolocation signals

Baumann-Pickering, S. | McDonald, M. . | Simonis, A. E. | Solsona Berga, A. | Merkens, K. P. | Oleson, E. M. | Roch, M. A. | Wiggins, S. M. | Rankin, S. | Yack, T. M. | Hildebrand, J. A.

2013 August Beaked Whale | Echolocation

Beaked whale echolocation signals are mostly frequency-modulated (FM) upsweep pulses and appear to be species specific. Evolutionary processes of niche separation may have driven differentiation of beaked whale signals used for spatial orientation and foraging. FM pulses of eight species of beaked whales were identified, as well as…

View More

Site specific probability of passive acoustic detection of humpback whale calls from single fixed hydrophones

Helble, T. A. | D'Spain, G. L. | Hildebrand, J. A. | Campbell, G. S. | Campbell, R. L. | Heany, K. D. |

2013 August PassiveAcoustics | Detection | Humpback Whale | Vocalization

Passive acoustic monitoring of marine mammal calls is an increasingly important method for assessing population numbers, distribution, and behavior. A common mistake in the analysis of marine mammal acoustic data is formulating conclusions about these animals without first understanding how environmental properties such as…

View More

Tracking dolphin whistles using an autonomous acoustic recorder array

Wiggins, S. M. | Frasier, K. E. | Henderson, E. E. | Hildebrand, J. A.

2013 June Delphinid | Whistles | Passive Acoustics | Three Dimensional Acoustic Tracking

Dolphins are known to produce nearly omnidirectional whistles that can propagate several kilometers, allowing these sounds to be localized and tracked using acoustic arrays. During the fall of 2007, a km-scale array of four autonomous acoustic recorders was deployed offshore of southern California in a known dolphin habitat at ~800 m…

View More

Baird’s beaked whale echolocation signals

Baumann-Pickering, S. | Yack, T. M. | Barlow, J. P. | Wiggins, S. M. | Hildebrand, J. A.

2013 June Beaked Whale | Echolocation

Echolocation signals from Baird's beaked whales were recorded during visual and acoustic shipboard surveys of cetaceans in the California Current ecosystem and with autonomous, long-term recorders in the Southern California Bight. The preliminary measurement of the visually validated Baird's beaked whale echolocation signals…

View More

Relationship between container ship underwater noise levels and ship design, operational and oceanographic conditions

McKenna, M. F. | Wiggins, S. M. | Hildebrand, J. A.

2013 May Ship Noise | Anthropogenic Noise

Low-frequency ocean ambient noise is dominated by noise from commercial ships, yet understanding how individual ships contribute deserves further investigation. This study develops and evaluates statistical models of container ship noise in relation to design characteristics, operational conditions and oceanographic settings. Five-…

View More

Bryde’s whale calls recorded in the Gulf of Mexico

Širović, A. | Bassett, H. R. | Johnson, S. C. | Wiggins, S. M. | Hildebrand, J. A.

2013 April Rice's Whale | Bryde's Whale | Vocalization | Gulf of Mexico

Bryde's whales (Balaenoptera edeni) inhabit tropical and subtropical waters worldwide and, unlike most other mysticetes, they are not thought to make long seasonal migrations (Jefferson et al. 2008). They are the only balaenopterid regularly found in the U.S. waters of the Gulf of Mexico (GOM), with their range likely constrained to the…

View More

Underwater radiated noise levels of a research icebreaker in the central arctic ocean

Roth, E. H. | Schmidt, V. | Hildebrand, J. A. | Wiggins, S. M.

2013 April Ship Noise | Anthropogenic Noise | Arctic

U.S. Coast Guard Cutter Healy's underwater radiated noise signature was characterized in the central Arctic Ocean during different types of ice-breaking operations. Propulsion modes included transit in variable ice cover, breaking heavy ice with backing-and-ramming maneuvers, and dynamic positioning with the bow thruster in operation…

View More

Detection, Classification, and Localization of Cetaceans by groups at the Scripps Institution of Oceanography and San Diego State University (2003-2013)

Roch, M. A. | Širović, A. | Baumann-Pickering, S.

2013 Detection | Classification | Localization | Cetacean

Cetaceans produce a wide variety of sounds, each presenting different sets of challenges in detection, classification, and localization. In general, baleen whales, or mysticetes, tend to have lower frequency calls. While the calls themselves tend to be simpler than those of some other species, the low frequency environment is a challenging…

View More
View PDF

DCL | Paris, France

Temporal separation of two fin whale call types across the eastern North Pacific

Širović, A. | Williams, L. N. | Kerosky, S. M. | Wiggins, S. M. | Hildebrand, J. A.

2012 September Fin Whale | Vocalization | Northeast Pacific

Fin whales (Balaenoptera physalus) produce a variety of low-frequency, short-duration, frequency-modulated calls. The differences in temporal patterns between two fin whale call types are described from long-term passive acoustic data collected intermittently between 2005 and 2011 at three locations across the eastern North Pacific…

View More

A quieting ocean: Unintended consequence of a fluctuating economy

McKenna, M. F. | Katz, S. L. | Wiggins, S. M. | Ross, D. | Hildebrand, J. A.

2012 August Ambient Noise | Anthropogenic Noise

Simultaneous long-term monitoring of underwater sound and ship traffic provided an opportunity to study how low-frequency noise correlated with ocean-based commercial shipping trends. Between 2007 and 2010 changes in regional shipping off southern California occurred as a consequence of economic and regulatory events…

View More

A generalized power-law detection algorithm for humpback whale vocalizations

Helble, T. A. | Ierley, G. R. | D'Spain, G. L. | Roch, M. A. | Hildebrand, J. A.

2012 April Detection | Humpback Whale | Vocalization

Conventional detection of humpback vocalizations is often based on frequency summation of band-limited spectrograms under the assumption that energy (square of the Fourier amplitude) is the appropriate metric. Power-law detectors allow for a higher power of the Fourier amplitude, appropriate when the signal occupies a limited but…

View More

Bryde’s whale seasonal range expansion and increasing presence in the Southern California Bight from 2000 to 2010

Kerosky, S. M. | Širović, A. | Roche, L. K. | Baumann-Pickering, S. | Wiggins, S. M. | Hildebrand, J. A.

2012 April Bryde's Whale | Seasonality | Presence | California

Bryde's whales (Balaenoptera edeni) are commonly found in tropical and subtropical regions of the Pacific Ocean, but few studies have explored the presence of Bryde's whales at the boundary of their distribution range. Such studies are increasingly relevant as climate impact models predict the range expansion of warm water species…

View More

Aleutian Islands beaked whale echolocation signals

Baumann-Pickering, S. | Simonis, A. E. | Wiggins, S. M. | Brownell Jr., R. L. | Hildebrand, J. A.

2012 March Beaked Whale | Echolocation | Aleutian Islands

Beaked whales are an elusive group of marine mammals. They are infrequently encountered as they are pelagic, deep diving foragers with short surface intervals between long dives (Tyack et al. 2006). In recent years, research has shown that beaked whales produce frequency modulated (FM) upsweep echolocation signals (Zimmer…

View More

High-frequency modulated signals of killer whales (Orcinus orca) in the North Pacific

Simonis, A. E. | Baumann-Pickering, S. | Oleson, E. M. | Melcon, M. L. | Gassmann, M. | Wiggins, S. M. | Hildebrand, J. A.

2012 March Killer Whale | High-Frequency | North Pacific

Killer whales in the North Pacific, similar to Atlantic populations, produce high-frequency modulated signals, based on acoustic recordings from ship-based hydrophone arrays and autonomous recorders at multiple locations. The median peak frequency of these signals ranged from 19.6-36.1 kHz and median duration ranged from…

View More

Blue Whales Respond to Anthropogenic Noise

Melcon, M. L. | Debich (Cummins), A. J. | Kerosky, S. M. | Roche, L. K. | Wiggins, S. M. | Hildebrand, J. A.

2012 February Blue Whale | Anthropogenic Noise | Passive Acoustics | California

Anthropogenic noise may significantly impact exposed marine mammals. This work studied the vocalization response of endangered blue whales to anthropogenic noise sources in the mid-frequency range using passive acoustic monitoring in the Southern California Bight. Blue whales were less likely to produce calls when mid-frequency…

View More

Beaked whale and dolphin tracking using a multichannel autonomous acoustic recorder

Wiggins, S. M. | McDonald, M. A. | Hildebrand, J. A.

2012 January Beaked Whale | Delphinid | Three Dimensional Acoustic Tracking | Autonomous Acoustic Recording

To track highly directional echolocation clicks from odontocetes, passive hydrophone arrays with small apertures can be used to receive the same high frequency click on each sensor. A four-hydrophone small-aperture array was coupled to an autonomous acoustic recorder and used for long-term tracking of high-frequency odontocete…

View More

Underwater ambient noise on the Chukchi Sea continental slope from 2006-2009

Roth, E. H. | Hildebrand, J. A. | Wiggins, S. M. | Ross, D.

2012 January Ambient Noise | Passive Acoustics | Arctic

From September 2006 to June 2009, an autonomous acoustic recorder measured ambient noise north of Barrow, Alaska on the continental slope at 235 m depth, between the Chukchi and Beaufort Seas. Mean monthly spectrum levels, selected to exclude impulsive events, show that months with open-water had the highest noise levels…

View More

Underwater radiated noise from modern commercial ships

McKenna, M. F. | Ross, D. | Wiggins, S. M. | Hildebrand, J. A.

2012 January Autonomous Acoustic Recording | Anthropogenic Noise | Ship Noise

Underwater radiated noise measurements for seven types of modern commercial ships during normal operating conditions are presented. Calibrated acoustic data (<1000 Hz) from an autonomous seafloor-mounted acoustic recorder were combined with ship passage information from the Automatic Identification System. This approach…

View More

Using passive acoustics to model blue whale habitat off the Western Antarctic Peninsula

Širović, A. | Hildebrand, J. A.

2011 December Blue Whale | Passive Acoustics | Habitat Modeling | Antarctica

Habitat preferences of calling blue whales were investigated using data from two multidisciplinary oceanographic cruises conducted off the Western Antarctic Peninsula (WAP) during the austral falls of 2001 and 2002. Data were collected on depth, temperature, salinity, chlorophyll a (Chl-a) concentration, krill biomass, zooplankton…

View More

Description of sounds recorded from Longman’s beaked whale, Indopacetus pacificus

Rankin, S. | Baumann-Pickering, S. | Yack, T. M. | Barlow, J. P.

2011 October Beaked Whale | Vocalization | Call Repertoire

Sounds from Longman’s beaked whale, Indopacetus pacificus, were recorded during shipboard surveys of cetaceans surrounding the Hawaiian Islands archipelago; this represents the first known recording of this species. Sounds included echolocation clicks and burst pulses. Echolocation clicks were grouped into three categories…

View More

Automated extraction of odontocete whistle contours

Roch, M. A. | Brandes, T. S. | Patel, B. | Barkley, Y. | Baumann-Pickering, S. | Soldevilla, M. S.

2011 October Automated Process | Odontocete | Whistles

Many odontocetes produce frequency modulated tonal calls known as whistles. The ability to automatically determine time × frequency tracks corresponding to these vocalizations has numerous applications including species description, identification, and density estimation. This work develops and compares two algorithms on a…

View More

Classification of behavior using vocalizations of Pacific white-sided dolphins (Lagenorhynchus obliquidens)

Henderson, E. E. | Hildebrand, J. A. | Smith, M. H.

2011 July Delphinid | Pacific White-Sided Dolphin | Classification | Acoustic Behavior | Vocalization | California

Surface behavior and concurrent underwater vocalizations were recorded for Pacific white-sided dolphins in the Southern California Bight (SCB) over multiple field seasons spanning 3 years. Clicks, click trains, and pulsed calls were counted and classified based on acoustic measurements, leading to the identification of 19 key call…

View More

The behavioral context of common dolphin (Delphinus sp.) vocalizations

Henderson, E. E. | Hildebrand, J. A. | Smith, M. H. | Falcone, E. A.

2011 July Delphinid | Common Dolphin | Acoustic Behavior | Vocalization | California

Correlations between surface behavior and concurrent underwater vocalizations were modeled for common dolphins (Delphinus spp.) in the Southern California Bight (SCB) over multiple field seasons. Clicks, pulsed calls, and whistles were examined, with a total of 50 call features identified. Call features were used to classify behavior using…

View More

North Pacific right whale up-call source levels and propagation distance on the southeastern Bering Sea shelf

Munger, L. M. | Wiggins, S. M. | Hildebrand, J. A.

2011 June North Pacific Right Whale | Source Levels | Ambient Noise | Bering Sea

Call source levels, transmission loss, and ambient noise levels were estimated for North Pacific right whale (Eubalaena japonica) up-calls recorded in the southeastern Bering Sea in autumn of 2000 and 2001. Distances to calling animals, needed to estimate source levels, were based on two independent techniques: (1) arrival-time…

View More

Estimating North Pacific right whale (Eubalaena japonica) density using passive acoustic cue counting

Marques, T. A. | Thomas, L. | Munger, L. M. | Wiggins, S. M. | Hildebrand, J. A.

2011 March North Pacific Right Whale | Density | Passive Acoustics

We present a method for estimating animal density from fixed passive acoustic detectors, and illustrate it by estimating the density of North Pacific right whales Eubalaena japonica in the areas surrounding 3 hydrophones deployed in the southeastern Bering Sea in 2001 to 2002 and 2005 to 2006. Input data were the distances to…

View More

Risso’s and Pacific white-sided dolphin habitat modeling from passive acoustic monitoring

Soldevilla, M. S. | Wiggins, S. M. | Hildebrand, J. A. | Oleson, E. M. | Ferguson, M. C.

2011 February Risso's Dolphin | Pacific White-Sided Dolphin | Habitat Modeling | Passive Acoustics

Habitat characterization allows prediction of dolphin distributions in response to oceanographic processes and can be used to understand and predict effects of anthropogenic disturbances. Many habitat models focus on contemporary dolphin occurrence and environmental predictor data, but time-lagged oceanographic data may…

View More

Classification of echolocation clicks from odontocetes in the Southern California Bight

Roch, M. A. | Klinck, H. | Baumann-Pickering, S. | Mellinger, D. K. | Qui, S. | Soldevilla, M. S. | Hildebrand, J. A.

2011 February Classification | Echolocation | Odontocete | California

This study presents a system for classifying echolocation clicks of six species of odontocetes in the Southern California Bight: Visually confirmed bottlenose dolphins, short- and long-beaked common dolphins, Pacific white-sided dolphins, Risso’s dolphins, and presumed Cuvier’s beaked whales. Echolocation clicks are represented by…

View More

Monitoring Marine Mammal Acoustics Using Wave Glider

Wiggins, S. M. | Manley, J. | Brager, E. | Woolhiser, B.

2010 December Acoustic Monitoring | Wave Glider

The Wave Glider, a wave-powered unmanned maritime vehicle (UMV), represents a novel and unique approach to persistent ocean presence. Wave Gliders harvest the abundant energy contained in ocean waves to provide essentially limitless propulsion. The Wave Glider can operate as a vessel, covering long distances in the ocean, or as a…

View More

Discriminating features of echolocation clicks of melon-headed whales (Peponocephala electra), bottlenose dolphins (Tursiops truncatus), and Gray’s spinner dolphins (Stenella longirostris longirostris)

Baumann-Pickering, S. | Wiggins, S. M. | Hildebrand, J. A. | Roch, M. A. | Schnitzler, H. U.

Date Published: October 18, 2010 Echolocation | Detection | Delphinid | Palmyra Atoll

Spectral parameters were used to discriminate between echolocation clicks produced by three dolphin species at Palmyra Atoll: melon-headed whales (Peponocephala electra), bottlenose dolphins (Tursiops truncatus) and Gray’s spinner dolphins (Stenella longirostris longirostris). Single species acoustic behavior during daytime…

View More

Echolocation signals of a beaked whale at Palmyra Atoll

Baumann-Pickering, S. | Wiggins, S. M. | Roth, E. H. | Roch, M. A. | Schnitzler, H. U. | Hildebrand, J. A.

2010 June Beaked Whale | Echolocation | Palmyra Atoll

Acoustic recordings from Palmyra Atoll, northern Line Islands, central Pacific, showed upsweep frequency modulated pulses reminiscent of those produced by beaked whales. These signals had higher frequencies, broader bandwidths, longer pulse durations and shorter inter-pulse intervals than previously described pulses of Blainville’s…

View More

Spatio-temporal comparison of Pacific white-sided dolphin echolocation click types

Soldevilla, M. S. | Wiggins, S. M. | Hildebrand, J. A.

2010 March Spatio-Temporal | Pacific White-Sided Dolphin | Echolocation | Diel Pattern | Seasonality | California

A comparison of temporal and geographical trends in different echolocation click types produced by Pacific white-sided dolphin Lagenorhynchus obliquidens can lead to insights into the significance of their usage by the dolphins. Using autonomous seafloor recording packages, the spatial, diel and seasonal patterns of Pacific white-…

View More

Spatial and temporal patterns of Risso’s dolphin echolocation in the Southern California Bight

Soldevilla, M. S. | Wiggins, S. M. | Hildebrand, J. A.

2010 January Spatio-Temporal | Risso's Dolphin | Echolocation | California

Geographical and temporal trends in echolocation clicking activity can lead to insights into the foraging and migratory behaviors of pelagic dolphins. Using autonomous acoustic recording packages, the geographical, diel, and seasonal patterns of Risso’s dolphin (Grampus griseus) echolocation click activity are described for six locations in…

View More

Engineering Tools for Studying Marine Mammals

Wiggins, S. M.

2010 Autonomous Acoustic Recording

Studying whales and dolphins (cetaceans) can be challenging because they often occupy remote, inhospitable areas, spend much of their lives underwater, and have diverse behaviors and habitats. With ship-based visual observations, the traditional method of studying marine mammals in the ocean, animals can be counted and their…

View More
View PDF

Frontiers of Engineering | Reports on Leading-Edge Engineering from the 2009 Symposium: The National Academies Press | 13-21

Anthropogenic and natural sources of ambient noise in the ocean

Hildebrand, J. A.

2009 December Anthropogenic Noise | Ship Noise | Sonar | Airguns | Ambient Noise

Ocean ambient noise results from both anthropogenic and natural sources. Different noise sources are dominant in each of 3 frequency bands: low (10 to 500 Hz), medium (500 Hz to 25 kHz) and high (>25 kHz). The low-frequency band is dominated by anthropogenic sources: primarily, commercial shipping and, secondarily, seismic…

View More

Baleen whale distribution relative to surface temperature and zooplankton abundance off southern California, 2004-2008

Munger, L. M. | Camancho, D. | Havron, A. | Campbell, G. S. | Calambokidis, J. | Douglas, A. B. | Hildebrand, J. A.

2009 December Spatio-Temporal | Baleen Whale | Temperature | California

We investigated the spatial and temporal variation in distributions of three large baleen whale species off southern California in relation to sea surface temperature (SST) and zooplankton displacement volume using Geographic Information System (GIS) software Data were collected on sixteen California Cooperative Oceanic Fisheries…

View More
View PDF

CalCOFI Report | Vol. 50:155-168

The Wave Glider, an Energy-Harvesting Autonomous Surface Vessel

Willcox, S. | Manley, J. | Wiggins, S. M.

2009 November Wave Glider | Autonomous Acoustic Recording

The Wave Glider is a new wave-propelled, persistent ocean vehicle. Roger Hine, the lead inventor of the vehicle and the chief executive officer of Liquid Robotics Inc., began work on the vehicle in 2005 with a vision to enable new types of ocean observation that would not require costly deepwater moorings or ship operations. The key…

View More
View PDF

Sea Technology | November 2009 Issue 29-32

Worldwide Decline in Tonal Frequencies of Blue Whale Songs

McDonald, M. A. | Hildebrand, J. A. | Mesnick, S.

2009 October Blue Whale | Vocalization | Ambient Noise

Blue whale Balaenoptera musculus songs can be divided into at least 10 types worldwide, each type retaining the same units and similar phrasing over decades, unlike humpback whale song which changes substantially from year to year. Historical acoustic recordings dating back as far as the 1960s were examined, measuring…

View More

Blue Whale B and D Call Classification Using a Frequency Domain Based Robust Contour Extractor

Madhusudhana, S. K. | Roch, M. A. | Oleson, E. M. | Soldevilla, M. S. | Hildebrand, J. A.

2009 October Blue Whale | Classification | Call Repertoire

Passive acoustic monitoring of blue whales (Balaenoptera musculus) has been used to gain insight into their presence and behavior. Many of their calls have been shown to be detectable through spectrogram correlation due to the low variation in these stereotyped calls. In this work, we describe rule based classifiers for tonal B and D calls…

View More

Behavior of melon-headed whales, Peponocephala electra, near oceanic islands

Brownell Jr., R. L. | Ralls, K. | Baumann-Pickering, S. | Poole, M. M.

2009 July Melon-Headed Whale | Sonar | Hawaii

Southall et al. (2006) concluded that a near mass stranding (MS) of melonheaded whales (MHWs), Peponocephala electra, in Hanalei Bay, Kauai, Hawaii, on 3-4 July 2004, was likely related to the operation of mid-frequency sonars (MFS). However, subsequent authors argued that the nearly simultaneous entry of MHWs into Sasanhaya…

View More

An acoustic survey of beaked whales at Cross Seamount near Hawaii (L)

McDonald, M. A. | Hildebrand, J. A. | Wiggins, S. M. | Johnston, D. W. | Polovina, J. J.

2009 February Beaked Whale | Bioacoustics | Call Abundance | Seamount | Hawaii

An acoustic record from Cross Seamount, southwest of Hawaii, revealed sounds characteristic of beaked whale echolocation at the same relative abundance year-around (270 of 356 days), occurring almost entirely at night. The most common sound had a linear frequency upsweep from 35 to 100kHz (the bandwidth of recording), an…

View More

Blue and fin whale acoustic presence around Antarctica during 2003 and 2004

Širović, A. | Hildebrand, J. A. | Wiggins, S. M. | Thiele, D.

2009 January Blue Whale | Fin Whale | Passive Acoustics | Antarctica

Seasonal and spatial variations of blue (Balaenoptera musculus) and fin whale (B. physalus) calls were analyzed from recordings collected with Acoustic Recording Packages (ARPs) deployed between January 2003 and July 2004 at four circumpolar locations: the Western Antarctic Peninsula (WAP), the Scotia Sea (SS), Eastern…

View More

Foraging behavior of humpback whales: kinematic and respiratory patterns suggest a high cost for a lunge

Goldbogen, J. A. | Calambokidis, J. | Croll, D. A. | Harvey, J. T. | Newton, K. M. | Oleson, E. M. | Schorr, G. | Shadwick, R. E.

2008 November Humpback Whale | Dive Behavior | Foraging

Lunge feeding in rorqual whales is a drag-based feeding mechanism that is thought to entail a high energetic cost and consequently limit the maximum dive time of these extraordinarily large predators. Although the kinematics of lunge feeding in fin whales supports this hypothesis, it is unclear whether respiratory compensation…

View More

North Pacific right whale (Eubalaena japonica) seasonal and diel calling patterns from long-term acoustic recordings in the southeastern Bering Sea, 2000-2006

Munger, L. M. | Wiggins, S. M. | Moore, S. E. | Hildebrand, J. A.

2008 October North Pacific Right Whale | Seasonality | Diel Pattern | Long-Term Acoustic Monitoring | Bering Sea

We assessed North Pacific right whale (Eubalaena japonica) seasonal and daily calling patterns in the southeastern Bering Sea (SEBS) using long-term hydrophone recordings from October 2000 through January 2006. We detected right whale calls on the SEBS middle shelf (<100 m depth) as early as May, intermittently throughout…

View More

A 50 Year comparison of ambient ocean noise near San Clemente Island: A bathymetrically complex coastal region off Southern California

McDonald, M. A. | Hildebrand, J. A. | Wiggins, S. M. | Ross D.

2008 October Ambient Noise | California

Repeated ocean ambient noise measurements at a shallow water (110 m) site near San Clemente Island reveal little increase in noise levels in the absence of local ships. Navy reports document ambient noise levels at this site in 1958-1959 and 1963-1964 and a seafloor recorder documents noise during 2005-2006. When noise from local…

View More

Classification of Risso’s and Pacific white-sided dolphins using spectral properties of echolocation clicks

Soldevilla, M. S. | Henderson, E. E. | Campbell, G. S. | Roch, M. A. | Wiggins, S. M. | Hildebrand, J. A.

2008 July Classification | Echolocation | Delphinid | Common Dolphin | Risso's Dolphin | Pacific White-Sided Dolphin

The spectral and temporal properties of echolocation clicks and the use of clicks for species classification are investigated for five species of free-ranging dolphins found offshore of southern California: short-beaked common (Delphinus delphis), long-beaked common (D. capensis), Risso’s (Grampus griseus), Pacific white-sided…

View More

Frequency based Algorithm for Robust Contour Extraction of Blue Whale B and D calls

Madhusudhana, S. K. | Oleson, E. M. | Soldevilla, M. S. | Roch, M. A. | Hildebrand, J. A.

2008 May Blue Whale | Vocalization | Automated Process

The sea is home to a myriad of marine animal species, many of which use sound as a primary means of communication, navigation and foraging. Of particular interest are the Blue whales (Balaenoptera musculus) of the cetacean family. Massive commercial whaling prior to 1960 brought the species close to extinction and its population…

View More

Comparison of machine learning techniques for the classification of echolocation clicks from three species of odontocetes

Roch, M. A. | Soldevilla, M. S. | Hoenigman, R. | Wiggins, S. M. | Hildebrand, J. A.

2008 March Classification | Echolocation | Machine Learning | Automated Process | Odontocete | Beaked Whale | Risso's Dolphin | Short-Finned Pilot Whale

A species classifier is presented which decides whether or not short groups of clicks are produced by one or more individuals from the following species: Blainville's beaked whales, short-finned pilot whales, and Risso's dolphins. The system locates individual clicks using the Teager energy operator and then constructs feature vectors…

View More
View PDF

Canadian Acoustics | Vol. 36(1):41-47

Temporal patterns in the acoustic signals of beaked whales at Cross Seamount

Johnston, D. W. | McDonald, M. A. | Polovina, R. | Domokos, S. | Wiggins, S. M. | Hildebrand, J. A.

2008 February Beaked Whale | Echolocation | Vocalization | Passive Acoustics | Seamount

Seamounts may influence the distribution of marine mammals through a combination of increased ocean mixing, enhanced local productivity and greater prey availability. To study the effects of seamounts on the presence and acoustic behaviour of cetaceans, we deployed a high-frequency acoustic recording package on the summit of…

View More

Anatomic Geometry of Sound Transmission and Reception in Cuvier’s Beaked Whale (Ziphius cavirostris)

Cranford, T. W. | McKenna, M. F. | Soldevilla, M. S. | Wiggins, S. M. | Goldbogen, J. A. | Shadwick, R. E. | Krysl, P. | St. Leger, J. A. | Hildebrand, J. A.

2008 January Beaked Whale

This study uses remote imaging technology to quantify, compare, and contrast the cephalic anatomy between a neonate female and a young adult male Cuvier's beaked whale. Primary results reveal details of anatomic geometry with implications for acoustic function and diving. Specifically, we describe the juxtaposition of the large…

View More

Big gulps require high drag for fin whale lunge feeding

Goldbogen, J. A. | Pyenson, N. D. | Shadwick, R. E.

2007 November Fin Whale | Foraging

Fin whales Balaenoptera physalus exhibit one of the most extreme feeding methods among aquatic vertebrates. Fin whales, and other rorquals (Balaenopteridae), lunge with their mouth fully agape, thereby generating dynamic pressure to stretch their mouth around a large volume of prey-laden water, which is then filtered by racks of…

View More

Lagrangian finite element treatment of transient vibration/acoustics of biosolids immersed in fluids

Krysl, P. | Cranford, T. W. | Hildebrand, J. A.

2007 September Bioacoustics | Beaked Whale

Superposition principle is used to separate the incident acoustic wave from the scattered and radiated waves in a displacement-based finite element model. An absorbing boundary condition is applied to the perturbation part of the displacement. Linear constitutive equation allows for inhomogeneous, anisotropic materials, both fluids…

View More

Temporal separation of blue whale call types on a southern California feeding ground

Oleson, E. M. | Wiggins, S. M. | Hildebrand, J. A.

2007 September Blue Whale | Vocalization | Foraging | California

Northeast Pacific blue whales, Balaenoptera musculus, migrate annually between productive summer feeding grounds off North America and tropical winter breeding grounds off Central America. These migratory movements have been confirmed through acoustic monitoring of the long-duration, low-frequency sounds produced by males…

View More

Blue and fin whale call source levels and propagation range in the Southern Ocean

Širović, A. | Hildebrand, J. A. | Wiggins, S. M.

2007 July Blue Whale | Fin Whale | Source Levels | Sound Propagation | Antarctica

Blue (Balaenoptera musculus) and fin whales (B. physalus) produce high-intensity, low-frequency calls, which probably function for communication during mating and feeding. The source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored…

View More

Evaluation of Postmortem Changes in Tissue Structure in the Bottlenose Dolphin (Tursiops truncatus)

McKenna, M. F. | Goldbogen, J. A. | St. Leger, J. | Hildebrand, J. A. | Cranford, T. W.

2007 July Bottlenose Dolphin

Postmortem changes in geometry, density, and sound speed within organs and tissues (melon, bone, blubber, and mandibular fat) of the dolphin head were evaluated using computed tomography (CT) scans of live and postmortem bottlenose dolphins (Tursiops truncatus). Specimens were classified into three different treatment groups:…

View More
View PDF

Anatomical Record | Vol. 290(8):1023-1032 | DOI:10.1002/ar.20565

Blue Whale Visual and Acoustic Encounter Rates in the Southern California Bight

Oleson, E. M. | Calambokidis, J. | Barlow, J. P. | Hildebrand, J. A.

2007 June Blue Whale | Visual Survey | Vocalization | California

The relationship between blue whale (Balaenoptera musculus) visual and acoustic encounter rates was quantitatively evaluated using hourly counts of detected whales during shipboard surveys off southern California. Encounter rates were estimated using temporal, geographic, and weather variables within a generalized additive model.…

View More

High-frequency Acoustic Recording Package (HARP) for broad-band, long-term marine mammal monitoring

Wiggins, S. M. | Hildebrand, J. A.

2007 June Long-Term Acoustic Monitoring | High-Frequency | Autonomous Acoustic Recording

Advancements in low-power and high-data-capacity consumer computer technology during the past decade have been adapted to autonomously record sounds from marine mammals over long periods. Acoustic monitoring has advantages over traditional visual surveys including greater detection ranges, continuous long-term monitoring…

View More

Gaussian mixture model classification of odontocetes in the Southern California Bight and the Gulf of California

Roch, M. A. | Soldevilla, M. S. | Burtenshaw, J. C. | Henderson, E. E. | Hildebrand, J. A.

2007 March Odontocete | Classification | California

A method for the automatic classification of free-ranging delphinid vocalizations is presented. The vocalizations of short-beaked and long-beaked common (Delphinus delphis and Delphinus capensis), Pacific white-sided (Lagenorhynchus obliquidens), and bottlenose (Tursiops truncatus) dolphins were recorded in a pelagic environment…

View More

Behavioral context of call production by eastern North Pacific blue whale

Oleson, E. M. | Calambokidis, J. | Burgess, W. C. | McDonald, M. A. | LeDuc, C. A. | Hildebrand, J. A.

2007 January Blue Whale | Acoustic Behavior | Northeast Pacific

We assessed the behavioral context of calls produced by blue whales Balaenoptera musculus off the California coast based on acoustic, behavioral, and dive data obtained through acoustic recording tags, sex determination from tissue sampling, and coordinated visual and acoustic observations. Approximately one-third of 38…

View More

Seasonal occurrence of low frequency whale vocalizations across eastern Antarctic and southern Australian waters, February 2004 to February 2007

Gedamke, J. | Gales, N. | Hildebrand, J. A. | Wiggins, S. M.

2007 Blue Whale | Fin Whale | Vocalization | Low-Frequency | Antarctica | Australia

Long term acoustic records of underwater sound can be used to assess the timing of migrations, peak periods of relative abundance, and seasonality and overlap of different species’ presence over large spatial scales. Long-term acoustic data was collected over large portions of the Southern Ocean between Australia and the Antarctic…

View More

Marine mammal monitoring and habitat investigations during CalCOFI surveys

Soldevilla, M. S. | Wiggins, S. M. | Calambokidis, J. | Douglas, A. B. | Oleson, E. M. | Hildebrand, J. A.

2006 December Cetacean | Acoustic Monitoring | Visual Survey | California

To understand cetacean ecology and habitat, a new component has been added to the CalCOFI ecosystem studies that have been conducted offshore of southern California over the last half century. In 2004, we initiated visual and acoustic line-transect surveys during CalCOFI cruises and long-term acoustic monitoring at selected…

View More
View PDF

CalCOFI Report | Vol. 47:79-91

Simulating the effect of high-intensity sound on cetaceans: Modeling approach and a case study for Cuvier's beaked whale (Ziphius cavirostris)

Krysl, P. | Cranford, T. W. | Wiggins, S. M. | Hildebrand, J. A.

2006 October Cetacean | Beaked Whale

A finite element model is formulated to study the steady-state vibration response of the anatomy of a whale (Cetacea) submerged in seawater. The anatomy was reconstructed from a combination of two-dimensional (2D) computed tomography (CT) scan images, identification of Hounsfield units with tissue types, and mapping of…

View More

An acoustic survey of baleen whales off Great Barrier Island

McDonald, M. A.

2006 September Baleen Whale | Acoustic Monitoring | New Zealand

Acoustic recordings of baleen whale calls were analysed for the calendar year 1997 from a pair of fixed hydrophones located 5 km east of Great Barrier Island, New Zealand. The primary goal of the study was to examine blue whale seasonally and song type as part of a larger worldwide study. Calls were recorded from blue whales of two…

View More

Increases in deep ocean ambient noise in the Northeast Pacific west of San Nicolas Island, California

McDonald, M. A. | Hildebrand, J. A. | Wiggins, S. M.

2006 August Ambient Noise | California

Recent measurement at a previously studied location illustrates the magnitude of increases in ocean ambient noise in the Northeast Pacific over the past four decades. Continuous measurements west of San Nicolas Island, California, over 138 days, spanning 2003-2004 are compared to measurements made during the 1960s at the…

View More

Acoustic detection and satellite-tracking leads to discovery of rare concentration of endangered North Pacific right whales

Wade, P. | Heide-Jørgensen, M. P. | Shelden, K. | Barlow, J. | Carretta, J. | Durban, J. | LeDuc, R. | Munger, L. M. | Rankin, S. | Sauter, A. | Stinchcomb, C.

2006 April North Pacific Right Whale | Acoustic Monitoring | Detection | Satellite Tracking

The North Pacific right whale, Eubalaena japonica, is one of the most endangered species of whale in the world. On 10 August 2004, two right whales were located in the Bering Sea using headings to right whale calls provided by directional sonobuoys. A satellite-monitored radio tag attached to one of these whales functioned for 40 days…

View More

Calibration of a Seawater Sound Velocimeter

Sweeney, A. D. | Chadwell, D. C. | Hildebrand, J. A.

2006 April Calibration | Temperature

We calibrated a sound velocimeter to a precision of ±0.034 m/s using Del Grosso’s sound-speed equation for seawater at temperatures of 2, 7.2, 11.7, and 18°C in a tank of seawater of salinity 33.95 at one atmosphere. The sound velocimeter measures the time-of-flight of a 4-MHz acoustic pulse over a 20-cm path by adjusting the…

View More

Kinematics of foraging dives and lunge-feeding in fin whales

Goldbogen, J. A. | Calambokidis, J. | Shadwick, R. E. | Oleson, E. M. | McDonald, M. A. | Hildebrand, J. A.

2006 March Fin Whale | Foraging | Dive Behavior

Fin whales are among the largest predators on earth, yet little is known about their foraging behavior at depth. These whales obtain their prey by lunge-feeding, an extraordinary biomechanical event where large amounts of water and prey are engulfed and filtered. This process entails a high energetic cost that effectively decreases dive…

View More

Listening for Large Whale in the Offshore Waters of Alaska

Moore, S. E. | Stafford, K. M | Mellinger, D. K. | Hildebrand, J. A.

2006 January Passive Acoustics | Alaska

In 1999, the first phase of a multiyear program was initiated at the National Oceanic and Atmospheric Administration's National Marine Mammal Laboratory and Pacific Marine Environmental Laboratory to advance the use of passive acoustics for the detection and assessment of large whales in offshore Alaskan waters. To date…

View More

Baleen whales in the Scotia Sea during January and February 2003

Širović, A. | Hildebrand, J. A. | Thiele, D.

2006 January Baleen Whale | Acoustic Monitoring | Visual Survey | Antarctica

Different species of baleen whales display distinct spatial distribution patterns in the Scotia Sea during the austral summer. Passive acoustic and visual surveys for baleen whales were conducted aboard the RRS James Clark Ross in the Scotia Sea and around South Georgia in January and February 2003. Identified calls from four species…

View More

Understanding the impacts of anthropogenic sound on beaked whales

Cox, T. M. | D'Spain, G. L. | Hildebrand, J. A. | et al.

2006 Anthropogenic Noise | Beaked Whale

This review considers the effect of anthropogenic sound on beaked whales2. Two major conclusions are presented: (1) gas-bubble disease, induced in supersaturated tissue by a behavioural response to acoustic exposure, is a plausible pathologic mechanism for the morbidity and mortality seen in cetaceans associated with sonar exposure…

View More

Biogeographic characterisation of blue whale song worldwide: using song to identify populations

McDonald, M. A. | Mesnick, S. L. | Hildebrand, J. A.

2006 Blue Whale | Vocalization | Communication | Distribution

Blue whale songs provide a measure for characterising worldwide blue whale population structure. These songs are divided into nine regional types, which maintain a stable character. Five of the nine song types have been recorded over time spans greater than 30 years showing no significant change in character. The nine song types…

View More

Sei whale sounds recorded in the Antarctic

McDonald, M. A. | Hildebrand, J. A. | Wiggins, S. M. | Thiele, D. | Glasgow, D. | Moore, S. E.

2005 December Sei Whale | Acoustic Monitoring | Vocalization | Antarctica

Sei whales are the least well known acoustically of all the rorquals, with only two brief descriptions of their calls previously reported. Recordings of low-frequency tonal and frequency swept calls were made near a group of four or five sei whales in waters west of the Antarctic Peninsula on 19 February 2003. These whales also produced…

View More

Blue Whale (Balaenoptera musculus) Diel Call Patterns Offshore of Southern California

Wiggins, S. M. | Oleson, E. M. | McDonald, M. A. | Hildebrand, J. A.

2005 September Blue Whale | Diel Pattern | Autonomous Acoustic Recording | California

Diel and seasonal calling patterns for blue whales (Balaenoptera musculus) were observed in coastal waters off southern California using seafloor- mounted autonomous acoustic recording packages (ARPs). Automated call counting from spectrogram cross-correlation showed peak seasonal calling in late summer/early fall. When call…

View More

Cuvier's beaked whale (Ziphius cavirostris) head tissues: physical properties and CT imaging

Soldevilla, M. S. | McKenna, M. F. | Wiggins, S. M. | Shadwick, R. E. | Cranford, T. W. | Hildebrand, J. A.

2005 June Beaked Whale

Tissue physical properties from a Cuvier's beaked whale (Ziphius cavirostris) neonate head are reported and compared with computed tomography (CT) X-ray imaging. Physical properties measured include longitudinal sound velocity, density, elastic modulus and hysteresis. Tissues were classified by type as follows: mandibular acoustic fat…

View More

Performance of spectrogram cross-correlation in detecting right whale calls in long-term recordings from the Bering Sea

Munger, L. M. | Mellinger, D. K. | Wiggins, S. M. | Moore, S. E. | Hildebrand, J. A.

2005 June North Pacific Right Whale | Long-Term Acoustic Monitoring | Detection | Bering Sea

We investigated the performance of spectrogram cross-correlation for automatically detecting North Pacific right whale (Eubalaena japonica) calls in long-term acoustic recordings from the southeastern Bering Sea. Data were sampled by autonomous, bottom-mounted hydrophones deployed in the southeastern Bering Sea from…

View More
View PDF

Canadian Acoustics | Vol. 32(2):25-34

Impacts of Anthropogenic Sound in Marine Mammal Research: Conservation Beyond Crisis

Hildebrand, J. A.

2005 Anthropogenic Noise | Stranding Event

There is growing concern that sound introduced into the sea by human activities has detrimental effects on marine mammals. For example, mounting evidence suggests that high-intensity anthropogenic sound from sonar and airguns leads to strandings and subsequent mortality of beaked whales. Although the mechanisms of injury in…

View More

Bottlenose Dolphins (Tursiops truncatus) in the Drowned Cayes, Belize: Group Size, Site Fidelity and Abundance

Kerr, K. A. | Defran, R. H. | Campbell, G. S.

2005 Bottlenose Dolphin | Abundance | Belize

Group size, site fidelity and abundance of bottlenose dolphins, Tursiops truncatus, were assessed during 392 photo-identification surveys conducted during 1997-1999 in the Drowned Cayes region, near Belize City, Belize, Central America. During this study 2155 dolphins were sighted across 736 groups. Mean group size was 2.9…

View More
View PDF

Caribbean Journal of Science | Vol. 41(1):172-177

Seasonality of blue and fin whale calls and the influence of sea ice in the Western Antarctic Peninsula

Širović, A. | Hildebrand, J. A. | Wiggins, S. M. | McDonald, M. A. | Moore, S. E. | Thiele, D.

2004 November Blue Whale | Fin Whale | Seasonality | Sea Ice | Antarctica

The calling seasonality of blue (Balaenoptera musculus) and fin (B. physalus) whales was assessed using acoustic data recorded on seven autonomous acoustic recording packages (ARPs) deployed from March 2001 to February 2003 in the Western Antarctic Peninsula. Automatic detection and acoustic power analysis methods were…

View More

Seasonal variability in whale encounters in the Western Antarctic Peninsula

Thiele, D. | Chester, E. T. | Moore, S. E. | Širović, A. | Hildebrand, J. A. | Friedlaender, A. S.

2004 November Cetacean | Visual Survey | Seasonality | Sea Ice | Antarctica

Cetacean sighting surveys were conducted as part of nine multidisciplinary research cruises over late summer, autumn and winter of 2 years (2001-2003) during the Southern Ocean Global Ocean Ecosystems (SO GLOBEC) program. Sea-ice cover differed markedly between years, with apparent effects on cetacean distribution. No ice…

View More

Acoustic and satellite remote sensing of blue whale seasonality and habitat in the Northeast Pacific

Burtenshaw, J. S. | Oleson, E. M. | Hildebrand, J. A. | McDonald, M. A. | Andrew, R. K. | Howe, B. M. | Mercer, J. A.

2004 September Blue Whale | Acoustic Monitoring | Satellite Tracking | Seasonality | Northeast Pacific

Northeast Pacific blue whales seasonally migrate, ranging from the waters off Central America to the Gulf of Alaska. Using acoustic and satellite remote sensing, we have continuously monitored the acoustic activity and habitat of blue whales during 1994-2000. Calling blue whales primarily aggregate off the coast of southern and…

View More

DIFAR Hydrophone Usage In Whale Research

McDonald, M. A.

2004 June Acoustic Monitoring

DIrectional Frequency Analysis and Recording (DIFAR) sonobuoys have been used by the Navy for many decades, providing magnetic bearings to low frequency (less than 4 kHz) sound sources from a single sensor. Computing advances have made this acoustic sensor technology increasingly easy to use and more powerful. The…

View More
View PDF

Canadian Acoustics | Vol. 32(2):155-160

Waveguide Propagation allows Range Estimates for North Pacific Right Whales in the Bering Sea

Wiggins, S. M. | McDonald, M. A. | Munger, L. M. | Moore, S. M. | Hildebrand, J. A.

2004 June Sound Propagation | North Pacific Right Whale | Bering Sea

The shallow and uniform water depth of the eastern Bering Sea shelf results in an acoustic waveguide. Propagation within this waveguide produces waveform dispersion which is dependent upon range. We present a means for using dispersed waveforms to determine range to calling whales from a single autonomous acoustic recording…

View More
View PDF

Canadian Acoustics | Vol. 32(2):146-154

Autonomous Acoustic Recording Packages (ARPs) for Long-Term Monitoring of Whale Sounds

Wiggins, S. M.

2003 June Long-Term Acoustic Monitoring | Autonomous Acoustic Recording

Advancements in low-power and high-data capacity computer technology during the past decade have been adapted to autonomously record acoustic data from vocalizing whales over long time periods. Acoustic monitoring of whales has advantages over traditional visual surveys including greater detection ranges, continuous long-…

View More

Low Frequency Calls of Bryde's Whales

Oleson, E. M. | Barlow, J. | Gordon, J. | Rankin, S. | Hildebrand, J. A.

2003 April Bryde's Whale | Vocalization | Low-Frequency

Despite significant effort, only two published reports describe Bryde's whale (Balaenoptera edeni) calls (Cummings et al. 1986, Edds et al. 1993). In both studies fundamental call frequencies were greater than 90 Hz, somewhat higher than the call frequencies attributed to other balaenopterids (Clark 1990, Edds-Walton 1997). Through…

View More

Acoustic and Visual Survey of Humpback Whale (Megaptera novaeangliae) Distribution in the Eastern and Southeastern Caribbean Sea

Swartz, S. L. | Cole, T. | McDonald, M. A. | Hildebrand, J. A. | Oleson, E. M. | Martinez, A. | Clapham, P. J. | Barlow, J. | Jones, M. L.

2003 Humpback Whale | Acoustic Monitoring | Visual Survey | Caribbean Sea

Humpback whales (Megaptera novaeangliae) historically ranged throughout the eastern and southeastern Caribbean Sea during the winter months. Commercial whaling from the 1820s to the early 1900s depleted the population. A combined passive acoustic and visual survey for humpback whales was conducted to assess the current winter…

View More
View PDF

Caribbean Journal of Science | Vol. 39(2):195-208

Acoustic identification of female Steller sea lions (Eumetopias jubatus)

Campbell, G. S. | Gisiner, R. C. | Helweg, D. A. | Milette, L. L.

2002 June Sea Lion | Identification | Vocalization

Steller sea lion (Eumetopias jubatus) mothers and pups establish and maintain contact with individually distinctive vocalizations. Our objective was to develop a robust neural network to classify females based on their mother-pup contact calls. We catalogued 573 contact calls from 25 females in 1998 and 1323 calls from 46 females in…

View More

Bottlenose dolphins (Tursiops truncatus) in Turneffe Atoll, Belize: occurrence, site fidelity, group size, and abundance

Campbell, G. S. | Bilgre, B. A. | Degran, R. H.

2002 January Bottlenose Dolphin | Abundance | Belize

Bottlenose dolphin (Tursiops truncatus) occurrence, site fidelity, group size, and population size were assessed within Turneffe Atoll, Belize, Central America during a 4-year photo-identification study. Five hundred and forty-nine photographic surveys were conducted between March 1992 and March 1996. Dolphin groups were…

View More
View PDF

Aquatic Mammals | Vol. 28(2):170-180

A robust model-based algorithm for localizing marine mammal transients

Tiemann, C. O. | Porter, M. B. | Hildebrand, J. A.

2002 January Humpback Whale | Blue Whale | Localization

Given the increasing interest in the effects of sound on marine mammals, a new model-based algorithm for localizing transient noises around a sparse, widely-distributed array of receivers has been developed and tested with real acoustic data. The robustness of the algorithm is illustrated in its application to two different scenarios with equal…

View More
View PDF

Impact of Littoral Environmental Variability of Acoustic Predictions and Sonar Performance| Book: 523-530 | DOI:10.1007/978-94-010-0626-2_65

The acoustic calls of blue whales off California with gender data

McDonald, M. A. | Calambokidis, J. | Teranishi, A. M. | Hildebrand, J. A.

2001 March Blue Whale | Vocalization | Bioacoustics | California

The acoustic calls of blue whales off California are described with visual observations of behavior and with acoustic tracking. Acoustic call data with corresponding position tracks are analyzed for five calling blue whales during one 100-min time period. Three of the five animals produced type A-B calls while two produced another call…

View More

Field measurements of sonic boom penetration into the ocean

Sohn, R. A. | Vernon, F. | Hildebrand, J. A. | Webb, S. C.

2000 May Anthropogenic Noise

Six sonic booms, generated by F-4 aircraft under steady flight at a range of altitudes (610-6100 m) and Mach numbers (1.07-1.26), were measured just above the air/sea interface, and at five depths in the water column. The measurements were made with a vertical hydrophone array suspended from a small spar buoy at the sea…

View More

Acoustic Models of Sound Production and Propagation

Aroyan, J. L. | McDonald, M. A. | Webb, S. C. | Hildebrand, J. A. | Clark, D. | Laitman, J. T. | Reidenberg, J. S.

2000 Blue Whale | Delphinid | Echolocation | Bioacoustics

Acoustic models based on physics and mathematics may yield significant advances in the understanding of sound production, propagation, and interaction associated with whales and dolphins. Models can be used to estimate the limits of intensity and frequency that are physically possible given the anatomy of a species. Models can…

View More
View PDF

Hearing by Whales and Dolphins | Book, Vol. 12:409-469 | DOI:10.1007/978-1-4612-1150-1_10

Acoustic detections of singing humpback whales (Megaptera novaeangliae) in the Eastern North Pacific during their northbound migration

Norris, T. F. | McDonald, M. A. | Barlow, J.

1999 June Humpback Whale | Detection | Migration | Northeast Pacific

Numerous (84) acoustic detections of singing humpback whales were made during a spring (08 March-09 June 1997) research cruise to study sperm whales in the central and eastern North Pacific. Over 15000 km of track-line was surveyed acoustically using a towed hydrophone array. Additionally, 83 sonobuoys were deployed…

View More

Blue and fin whales observed on seafloor array in the Northeast Pacific

McDonald, M. A. | Hildebrand, J. A. | Webb, S. C.

1995 March Blue Whale | Fin Whale | Northeast Pacific

Calling blue and fin whales have been tracked using relative travel times and amplitudes from both direct and multipath arrivals to a seafloor array of seismometers. Calls of three fin whales swimming in the same general direction, but several kilometers apart, are believed to represent communication between the whales because of signature…

View More