Year-round acoustic presence of sperm whales (Physeter macrocephalus) and baseline ambient ocean sound levels in the Greek Seas

The sperm whale (Physeter macrocephalus) is the largest odontocete occurring in the Greek Seas. However, monitoring thespecies’ spatiotemporal distribution patterns is especially difficult during the winter months when unfavorable weather conditionsoften hinder survey efforts. In the Greek Seas, visual cetacean surveys are typically not conducted between November and March. In a first attempt to collect year-round baseline information on sperm whale occurrence patterns in Greek waters, two Passive Aquatic Listeners (PALs) were deployed for 19 months, at Pylos Station (36.8 N, 21.6ο E) in the Hellenic Trench, and at Athos Station (40.0 N, 24.7ο E) in the North Aegean Trough. Results revealed the year-round presence of sperm whales at Pylos Station with a higher number of detections observed during late spring and throughout the summer. No sperm whale vocalizations were detected at Athos Station. An ambient sound level analysis revealed higher winter and lower summer levels at both sites largely driven by local weather conditions. Results showed that marine life in the Hellenic Trench area was exposed to higher low frequency (< 1 kHz) sound levels (by up to 10 dB re 1 μPa2/Hz). Ambient noise below 1 kHz is frequently dominated by anthropogenic sources including shipping. Ship strikes and noise disturbance constitute major threats for the small, genetically isolated, endangeredsperm whale population. The results of this study are useful for sperm whale conservation efforts in the region and may helppolicymakers in prioritizing mitigation measures, including the establishment of speed limits and rerouting of ship traffic.

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Slower Ship Speed in the Bahamas Due to COVID-19 Produces a Dramatic Reduction in Ocean Sound Levels

Frontiers in Marine Science ◽

10.3389/fmars.2021.673565 ◽

2021 ◽

Vol 8 ◽

Author(s):

Charlotte Dunn ◽

James Theriault ◽

Leigh Hickmott ◽

Diane Claridge

Keyword(s):

Sperm Whale ◽

Mitigation Measures ◽

Automatic Identification ◽

Identification System ◽

Density Level ◽

Underwater Sound ◽

Sperm Whales ◽

Ship Traffic ◽

Sound Levels ◽

Ship Speed

As underwater noise from ship traffic increases, profound effects on the marine environment highlight the need for improved mitigation measures. One measure, reduction in ship speed, has been shown to be one of the key drivers in reducing sound source levels of vessels. In 2017, a study began to assess the impacts of increasing commercial shipping traffic on sperm whales in Northwest Providence Channel, northern Bahamas, an international trade route that primarily serves the southeast US. Ship data were collected from an Automatic Identification System (AIS) station combined with recordings from an acoustic recorder to measure underwater sound levels and to detect the presence of sperm whales. Here we analyze a subset of these data to opportunistically investigate potential changes in ship traffic before and during the COVID-19 pandemic. These data span one calendar year from October 2019 to October 2020. A pre-COVID-19 dataset of 121 days, from a recorder approximately 2 km from the shipping route was compared to a 134-day dataset collected during COVID-19 from the same site, comprising 2900 and 3181 ten-minute recordings, respectively. A dramatic decrease in ocean noise levels concurrent with changes in shipping activity occurred during the pandemic. The mean pre-COVID-19 power density level in the 111–140 Hz 1/3-octave band was 88.81 dB re 1 μPa (range 81.38–100.90) and decreased to 84.27 dB re 1 μPa (range 78.60–99.51) during COVID-19, equating to a 41% reduction in sound pressure levels (SPL). After differences in seasonal changes in wind speed were accounted for, SPL decreased during the pandemic by 3.98 dB (37%). The most notable changes in ship activity were significantly reduced vessel speeds for all ship types and fewer ships using the area during the pandemic. Vessel speed was highly correlated to SPL and the only ship-based variable that predicted SPLs. Despite the opportunistic nature [i.e., not a standard before-after-control-impact (BACI) study], this study provides a unique opportunity to assess the effectiveness of ship traffic management strategies, such as slowing ships down, to mitigate impacts on marine life in the study area, including local sperm whale populations.

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The burst-pulse nature of ‘squeal’ sounds emitted by sperm whales (Physeter macrocephalus)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315407054549 ◽

2007 ◽

Vol 87 (1) ◽

pp. 39-46 ◽

Cited By ~ 12

Author(s):

Caroline R. Weir ◽

Alexandros Frantzis ◽

Paraskevi Alexiadou ◽

John C. Goold

Keyword(s):

Repetition Rate ◽

Low Frequency ◽

Sperm Whale ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Dominant Form ◽

Modulated Structures ◽

Burst Pulse ◽

Broadband Pulse ◽

Social Units

Sperm whales (Physeter macrocephalus) typically produce sharp onset, broadband pulse sounds at varying repetition rates. Acoustic recordings of different social units of sperm whales in the Mediterranean Sea included apparent non-click sounds of tonal quality, termed ‘squeals’. Quantitative analysis of the spectral signal and waveform indicate that although squeals are perceived as tonal and appear spectrally as narrowband frequency-modulated structures with harmonics, they actually consist of pulses at high repetition rates exceeding 1600 clicks/s. Squeals contained energy at between 400 Hz and 22 kHz, with mean peak energy at the relatively low frequency of 700 Hz. Five spectral forms of squeal could be recognized, with the dominant form (45%) of squeals showing a decrease in frequency along the squeal contour. Mean click repetition rate ranged between 713 and 1385 clicks/s for individual squeals, and also varied within squeals at rates of between 64 and 444 clicks/s. Variation in click repetition rate was reflected in the frequency spacing of the spectral sidebands, in a statistically significant inverse relationship. Squeals were recorded only during bouts of sperm whale social behaviour, consistent with their having a communicative social function. Sperm whale squeals are structurally and audibly similar to the burst-pulse sounds produced by many smaller odontocete species, and might fall on the continuum between distinct click trains and pure-tone whistles.

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Cetacean strandings along the Pacific and Caribbean coasts of Nicaragua from 2014 to 2021

Marine Biodiversity Records ◽

10.1186/s41200-021-00209-5 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Joëlle De Weerdt ◽

Eric Angel Ramos ◽

Etienne Pouplard ◽

Marc Kochzius ◽

Phillip Clapham

Keyword(s):

Marine Mammals ◽

Sperm Whale ◽

Distribution Patterns ◽

Sperm Whales ◽

The Pacific ◽

Toothed Whale ◽

Beaked Whales ◽

Causes Of Mortality ◽

Cuvier’S Beaked Whale ◽

Stenella Attenuata

AbstractDocumenting marine mammal strandings provides important information needed to understand the occurrence and distribution patterns of species. Here, we report on strandings of cetaceans on the Pacific (n = 11) and Caribbean (n = 2) coasts of Nicaragua, documented opportunistically from 2014 to 2021. Strandings included three species of baleen whale (blue whale Balaenoptera musculus, Bryde’s whale Balaenoptera edeni, humpback whale Megaptera novaeangliae) and five species of toothed whale (dwarf sperm whale Kogia sima, Guiana dolphin Sotalia guianensis, pantropical spotted dolphin Stenella attenuata, spinner dolphin Stenella longirostris, Cuvier’s beaked whale Ziphius cavirostris). These are the first published accounts of blue whales, Bryde’s whales, dwarf sperm whales, and Cuvier’s beaked whales in Nicaraguan waters. Limited resources and the advanced decomposition of animals prevented necropsies in most cases, the identification of the causes of mortality in all cases, and the species identification of two dolphins. Information derived from these stranding events offers new insights into the occurrence of marine mammals on the Pacific and Caribbean coasts of Nicaragua and Central America.

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Incubator Noise

PEDIATRICS ◽

10.1542/peds.56.4.617 ◽

1975 ◽

Vol 56 (4) ◽

pp. 617-617

Author(s):

Gōsta Blennow ◽

Nils W. Svenningsen ◽

Bengt Almquist

Keyword(s):

Low Frequency ◽

Sound Level ◽

Noise Levels ◽

Frequency Sound ◽

Mechanical Noise ◽

Sound Levels ◽

Infant Incubator ◽

Improved Model ◽

Model C

Recently we reported results from studies of incubator noise levels.1 It was found that in certain types of incubators the noise was considerable, and attention was called to the sound level in the construction of new incubators. Recently we had the opportunity to study an improved model of Isolette Infant Incubator Model C-86 where the mechanical noise from the electrically powered motor has been partially eliminated. With this modification it has been possible to lower the low-frequency sound levels to a certain degree in comparison to the levels registered in our study.

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INFRASOUND AND LOW FREQUENCY NOISE IMMISION FROM PIPELINES. iMPROVING THE ISO 1996-2:2017 PROPOSED METHODS. CASES STUDIES CONDUCTED AT LOS ANDES AND PERUVIAN RAINFOREST

Akustika ◽

10.36336/akustika201932335 ◽

2019 ◽

Vol 32 ◽

pp. 335-345

Author(s):

Walter Montano

Keyword(s):

Low Frequency ◽

Sound Level ◽

Frequency Noise ◽

Gas Extraction ◽

Howler Monkeys ◽

Noise Sources ◽

Industrial Facilities ◽

Sound Levels ◽

Continuous Noise ◽

Amazonian Rainforest

The gas extraction wells are in Amazonian rainforest and by them there are their industrial facilities. The pipeline has about 800 km with four pumps stations and two compressor stations. The challenge of conducting sound measurements was important-there is no specialized literature-and other noise "sources" are howler monkeys, cicadidae chirping, woodpeckers, trees´foliage, etc. However the problem is simply because those fixed industrial facilities are the only ones. People live in isolated hamlet on the side of dirt roads, so they are exposed 24/7 to the continuous noise; at homes 4 km away from the plants the sound level is 60 dBC, but in the spectrum of ILFN tones could not be identified. This Paper presents the procedures that were developed to identify the ILFN tones, improving the methods proposed in ISO 1996-2, writing a software that "automatically eliminates" the sound levels that don´t belong to the industry,

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Architecture of the sperm whale forehead facilitates ramming combat

PeerJ ◽

10.7717/peerj.1895 ◽

2016 ◽

Vol 4 ◽

pp. e1895 ◽

Cited By ~ 4

Author(s):

Olga Panagiotopoulou ◽

Panagiotis Spyridis ◽

Hyab Mehari Abraha ◽

David R. Carrier ◽

Todd C. Pataky

Keyword(s):

Connective Tissue ◽

Structural Engineering ◽

Sperm Whale ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Moby Dick ◽

Unique Structure ◽

Complex Structural ◽

Von Mises ◽

Von Mises Stresses

Herman Melville’s novelMoby Dickwas inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the “spermaceti organ” and “junk,” that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the spermaceti organ would reduce skull stresses, it would also cause high compressive stresses on the anterior aspect of the organ and the connective tissue case, possibly making these structures more prone to failure. This outcome, coupled with the facts that the spermaceti organ houses sensitive and essential sonar producing structures and the rostral portion of junk, rather than the spermaceti organ, is frequently a site of significant scarring in mature males suggest that whales avoid impact with the spermaceti organ. Although the unique structure of the junk certainly serves multiple functions, our results are consistent with the hypothesis that the structure also evolved to function as a massive battering ram during male-male competition.

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Cues, creaks, and decoys: using passive acoustic monitoring as a tool for studying sperm whale depredation

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv024 ◽

2015 ◽

Vol 72 (5) ◽

pp. 1621-1636 ◽

Cited By ~ 13

Author(s):

Aaron Thode ◽

Delphine Mathias ◽

Janice Straley ◽

Victoria O'Connell ◽

Linda Behnken ◽

...

Keyword(s):

Low Frequency ◽

Field Tests ◽

Sperm Whale ◽

Acoustic Monitoring ◽

Sperm Whales ◽

Passive Acoustic Monitoring ◽

Long Distance ◽

Fishing Activity ◽

Fishing Vessels ◽

Passive Acoustic

Abstract Since 2003, a collaborative effort (SEASWAP) between fishers, scientists, and managers has researched how Alaskan sperm whales locate demersal longline fishing activity and then depredate sablefish from gear. Sperm whales constantly produce relatively low-frequency biosonar signals whenever foraging; therefore, over the past decade, passive acoustic monitoring (PAM) has become a basic tool, used for both measuring depredation activity and accelerating field tests of potential depredation countermeasures. This paper reviews and summarizes past published PAM research on SEASWAP, and then provides a detailed example of how PAM methods are currently being used to test countermeasures. The review covers two major research thrusts: (i) identifying acoustic outputs of fishing vessels that provide long-distance “cues” that attract whales to fishing activity; and (ii) validating whether distinctive “creak” sounds can be used to quantify and measure depredation rates, using both bioacoustic tags and statistical comparisons between visual and acoustic depredation estimates during federal sablefish surveys. The latter part of the paper then provides an example of how PAM is being used to study a particular potential countermeasure: an “acoustic decoy” which transmits fishing vessel acoustic cues to attract animals away from true fishing activity. The results of an initial 2011 field trial are presented to show how PAM was used to design the decoy signals and monitor the efficacy of the deployment. The ability of PAM to detect both whale presence and depredation behaviour has reduced the need to deploy researchers or other specialists on fishing cruises. Instead, volunteer fishers can deploy “user-friendly” acoustic recorders on their gear, greatly facilitating the testing of various deterrents, and providing the industry and regulators a convenient and unobtrusive tool for monitoring both the scale and long-term spread of this behaviour across the Alaskan fishery.

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Socially segregated, sympatric sperm whale clans in the Atlantic Ocean

Royal Society Open Science ◽

10.1098/rsos.160061 ◽

2016 ◽

Vol 3 (6) ◽

pp. 160061 ◽

Cited By ~ 16

Author(s):

Shane Gero ◽

Anne Bøttcher ◽

Hal Whitehead ◽

Peter Teglberg Madsen

Keyword(s):

Social Interactions ◽

Sperm Whale ◽

Mantel Test ◽

Good Evidence ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Sympatric Populations ◽

The Pacific ◽

Matrix Correlation ◽

Social Units

Sperm whales ( Physeter macrocephalus ) are unusual in that there is good evidence for sympatric populations with distinct culturally determined behaviour, including potential acoustic markers of the population division. In the Pacific, socially segregated, vocal clans with distinct dialects coexist; by contrast, geographical variation in vocal repertoire in the Atlantic has been attributed to drift. We examine networks of acoustic repertoire similarity and social interactions for 11 social units in the Eastern Caribbean. We find the presence of two socially segregated, sympatric vocal clans whose dialects differ significantly both in terms of categorical coda types produced by each clan (Mantel test between clans: matrix correlation = 0.256; p ≤ 0.001) and when using classification-free similarity which ignores defined types (Mantel test between clans: matrix correlation = 0.180; p ≤ 0.001). The more common of the two clans makes a characteristic 1 + 1 + 3 coda, while the other less often sighted clan makes predominantly regular codas. Units were only observed associating with other units within their vocal clan. This study demonstrates that sympatric vocal clans do exist in the Atlantic, that they define a higher order level of social organization as they do in the Pacific, and suggests that cultural identity at the clan level is probably important in this species worldwide.

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Calves as social hubs: dynamics of the social network within sperm whale units

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.1113 ◽

2013 ◽

Vol 280 (1763) ◽

pp. 20131113 ◽

Cited By ~ 31

Author(s):

Shane Gero ◽

Jonathan Gordon ◽

Hal Whitehead

Keyword(s):

Social Relationships ◽

Social Role ◽

Group Formation ◽

Time Lag ◽

Group Living ◽

Sperm Whale ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Social Unit ◽

The Social

It is hypothesized that the primary function of permanent social relationships among female sperm whales ( Physeter macrocephalus ) is to provide allomothers for calves at the surface while mothers make foraging dives. In order to investigate how reciprocity of allocare within units of sperm whales facilitates group living, we constructed weighted social networks based on yearly matrices of associations (2005–2010) and correlated them across years, through changes in age and social role, to study changes in social relationships within seven sperm whale units. Pairs of association matrices from sequential years showed a greater positive correlation than expected by chance, but as the time lag increased, the correlation coefficients decreased. Over all units considered, calves had high values for all measured network statistics, while mothers had intermediate values for most of the measures, but high values for connectedness and affinity. Mothers showed sharp drops in strength and connectedness in the first year of their new calves' lives. These broad patterns appear to be consistent across units. Calves appeared to be significant nodes in the network of the social unit, and thus provide quantitative support for the theory in which communal care acts as the evolutionary force behind group formation in this species.

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Designing Unmanned Underwater Vehicles through Biomimicry

Scientific Bulletin of Naval Academy ◽

10.21279/1454-864x-21-i1-007 ◽

2021 ◽

Vol XXIV (1) ◽

pp. 61-73

Author(s):

TANER M.

Keyword(s):

Occupational Safety ◽

Weather Conditions ◽

Sperm Whale ◽

Underwater Vehicles ◽

Offshore Structures ◽

Physeter Macrocephalus ◽

Unmanned Underwater Vehicles ◽

Sea Bottom ◽

Small Craft ◽

Form Design

Research vessels or small craft equipped for the specific purposes lead geological, geophysical and oceanographic research both at the coastal and offshore areas for constructing and surveying the engineering projects such as offshore structures, undersea pipelines, harbours, oil and natural gas extraction plants from resources etc., which require extensive labourship. However, this research method applied entails very high costs and can also include risks for occupational safety and property due to the harsh weather conditions at sea. In addition, high precision measurements cannot always function from the sea surface during such research projects above-mentioned. Thus, unmanned underwater vehicles (UUVs) have been designed and produced intensively in the last two decades. The aim of this study was to generate form design of a proper unmanned underwater surveying vehicle to be able to conduct research on the geological and geophysical structure of the sea bottom as well as oceanographic opinions. Therefore, computational fluid dynamics (CFD) analysis of the DARPA Suboff submarine model was created, and the validation of the results obtained in these analyses was provided with those of the experiments of this DARPA Suboff model performed by Liu and Huang [1]. After successful conformity of the simulations carried out using the commercial software STAR CCM+ (Simulation of Turbulent flow in Arbitrary Regions - Computational Continuum Mechanics, C++ based), the UUV forms were created by means of different way including biomimicry methodology. In this context, the models of a mature goose-beaked whale (ziphius cavirostris), a mature sperm whale (physeter macrocephalus) and two torpedo-shaped UUV models as well a hybrid model including parts of a whale and torpedo-forms with the same displacement were analysed, and the results obtained were discussed.

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