Prey Fields and Habitat of Deep Diving Odontocetes: 3D Characterization and Modeling of Beaked and Sperm Whale Foraging Areas in the Tongue of the Ocean

2012 ◽  
Author(s):  
Douglas P. Nowacek ◽  
Louis St. Laurent ◽  
David J. Moretti ◽  
Patrick N. Halpin
Keyword(s):  
Sperm Whale ◽  
Deep Diving

scholarly journals Diversity, relative density and structure of the cetacean community in summer months east of Great Abaco, Bahamas

2004 ◽  
Vol 84 (2) ◽  
pp. 469-474 ◽  
Author(s):  
Colin D. MacLeod ◽  
Nan Hauser ◽  
Hoyt Peckham
Keyword(s):  
Relative Density ◽  
Sperm Whale ◽  
Similar Species ◽  
Beaked Whale ◽  
Stenella Frontalis ◽  
Deep Diving ◽  
Feeding Niche ◽  
Order Of Magnitude ◽  
Cuvier’S Beaked Whale ◽  
Water Depths

Little is known about cetacean communities in the tropical and sub-tropical Atlantic. This paper describes the cetacean community found east of Great Abaco in the northern Bahamas (26·5°N) during summer months between 1998 and 2001. Nine species of cetaceans were recorded, which could be divided into two distinct groupings: firstly, ‘permanent’ species, which had relative sightings rates between 0·026–0·084 sightings per hour and which were recorded on many occasions in all years and most months; secondly, ‘sporadic’ species, which had relative sightings rates an order of magnitude lower (0·004–0·008 sightings per hour) and which were recorded on very few occasions. The ‘permanent’ species were the Stenella frontalis (Atlantic spotted dolphin), Kogia simus (the dwarf sperm whale), Mesoplodon densirostris (Blainville's beaked whale) and Ziphius cavirostris (Cuvier's beaked whale). These four species differed significantly in the depth of grid squares utilized (χ=20·25, df=9, P<0·01) suggesting that these species occupied four separate niches. Stenella frontalis dominated the surface feeding niche, while the remaining three deep-diving species segregated into different depth ranges. Kogia simus was the dominant species in water depths of less than 200 m, M. densirostris in water depths of 200 to 1000 m and Z. cavirostris in water depths of greater than 1000 m. The overall relative density (2·533 individuals per hour of effort) and diversity of species in the study area was relatively low and may relate to low levels of local productivity. It is hypothesized that the four ‘permanent’ species may competitively exclude ecologically similar species, resulting in a reduced number of species and that ‘sporadic’ species may only enter the study area during times of higher than usual productivity when the ‘permanent’ species are no longer able to dominate their individual niches.

scholarly journals The nose of the sperm whale: overviews of functional design, structural homologies and evolution

2014 ◽  
Vol 96 (4) ◽  
pp. 783-806 ◽  
Author(s):  
Stefan Huggenberger ◽  
Michel André ◽  
Helmut H. A. Oelschläger
Keyword(s):  
Sperm Whale ◽  
Pulse Generation ◽  
Nasal Passage ◽  
Generation Process ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Acoustic Window ◽  
Deep Diving ◽  
Toothed Whale ◽  
Fat Bodies

The hypertrophic and much elongated epicranial (nasal) complex of sperm whales (Physeter macrocephalus) is a unique device to increase directionality and source levels of echolocation clicks in aquatic environments. The size and shape of the nasal fat bodies as well as the peculiar organization of the air sac system in the nasal sound generator of sperm whales are in favour of this proposed specialized acoustic function. The morphology of the sperm whale nose, including a ‘connecting acoustic window’ in the case and an anterior ‘terminal acoustic window’ at the rostroventral edge of the junk, supports the ‘bent horn hypothesis’ of sound emission. In contrast to the laryngeal mechanism described for dolphins and porpoises, sperm whales may drive the initial pulse generation process with air pressurized by nasal muscles associated with the right nasal passage (right nasal passage muscle, maxillonasolabialis muscle). This can be interpreted as an adaptation to deep-diving and high hydrostatic pressures constraining pneumatic phonation. Comparison of nasal structures in sperm whales and other toothed whales reveals that the existing air sac system as well as the fat bodies and the musculature have the same topographical relations and thus may be homologous in all toothed whales (Odontoceti). This implies that the nasal sound generating system evolved only once during toothed whale evolution and, more specifically, that the unique hypertrophied nasal complex was a main driving force in the evolution of the sperm whale taxon.

scholarly journals A first acoustic density estimate for sperm whales in Irish offshore waters

2020 ◽  
Vol 21 (1) ◽  
pp. 123-133
Author(s):  
Jonathan Gordon ◽  
Douglas Gillespie ◽  
Russell Leaper ◽  
Arthur Lee ◽  
Lindsay Porter ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Weather Conditions ◽  
Sperm Whale ◽  
Oil And Gas Industry ◽  
Line Transect ◽  
Commercial Fishing ◽  
Sperm Whales ◽  
Density Estimates ◽  
Deep Diving ◽  
Target Motion Analysis

Previous studies off western Ireland have suggested that substantial numbers of, mainly male, sperm whales may be found in these habitats. Whaling vessels operating from shore stations in Ireland in the early 20th century frequently caught sperm whales in oceanic waters. It is likely that this North Atlantic region contains important foraging habitats for this species, and that mature males must also migrate through this area moving between breeding grounds to the south and other feeding areas further north. Increasingly, these offshore waters are being utilised and potentially impacted by human industrial activities. For example, as inshore resources are depleted and technology improves, both the commercial fishing and the oil and gas industry are becoming more active in deeper waters beyond the continental margin. It is important therefore to better understand the biology and ecology of sperm whales in these more remote areas. However, their offshore location and deep diving habits, together with weather constraints in the exposed Atlantic, make research difficult. New sperm whale density estimates are reported using data from six seasonal passiveacoustic surveys carried out in two successive years (2015 and 2016). These covered a corridor approximately 110km wide which bounded a major portion of Ireland’s continental shelf break. Towed hydrophone line-transect methodologies were used, which have proven to be highly effective for surveying sperm whales in offshore waters and in poor weather conditions. Target motion analysis was applied to calculate the ranges of vocalising whales from the survey tracklines and the effective strip half-width calculated across all surveys was 7,958m. The study area was surveyedin three blocks and animal densities within these blocks varied between 1 and 4.6 individuals per 1,000km2 (CV 0.34 and 0.21 respectively) with an overall mean density in waters deeper than 300m of 3.2 individuals per 1,000km2(CV 0.04). These robust density estimates are the first of their kind for Irish waters and are similar to those reported in other Atlantic areas considered significant for this species. These results emphasise the significance of this region as sperm whale habitat. The results of this study should be used to inform the future sustainable development and management of Ireland’s offshore Atlantic.

Sperm whale sound production studied with ultrasound time/depth-recording tags

2002 ◽  
Vol 205 (13) ◽  
pp. 1899-1906 ◽  
Author(s):  
P. T. Madsen ◽  
R. Payne ◽  
N. U. Kristiansen ◽  
M. Wahlberg ◽  
I. Kerr ◽  
...  
Keyword(s):  
Sound Production ◽  
Ambient Pressure ◽  
Sperm Whale ◽  
Sound Pulse ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Hydrostatic Reduction ◽  
Deep Diving ◽  
Air Volume ◽  
Depth Recording

SUMMARYDelphinoids (Delphinidae, Odontoceti) produce tonal sounds and clicks by forcing pressurized air past phonic lips in the nasal complex. It has been proposed that homologous, hypertrophied nasal structures in the deep-diving sperm whale (Physeter macrocephalus) (Physeteridae, Odontoceti) are dedicated to the production of clicks. However, air volumes in diving mammals are reduced with increasing ambient pressure, which seems likely to influence pneumatic sound production at depth. To study sperm whale sound production at depth, we attached ultrasound time/depth-recording tags to sperm whales by means of a pole and suction cup. We demonstrate that sperm whale click production in terms of output and frequency content is unaffected by hydrostatic reduction in available air volume down to less than 2% of the initial air volume in the nasal complex. We present evidence suggesting that the sound-generating mechanism has a bimodal function, allowing for the production of clicks suited for biosonar and clicks more suited for communication. Shared click features suggest that sound production in sperm whales is based on the same fundamental biomechanics as in smaller odontocetes and that the nasal complexes are therefore not only anatomically but also functionally homologous in generating the initial sound pulse.

scholarly journals Contribution of social media to cetacean research in Southeast Asia: illuminating populations vulnerable to litter

2021 ◽  
Author(s):  
Amber Coram ◽  
Neil Angelo S. Abreo ◽  
Robert P. Ellis ◽  
Kirsten F. Thompson
Keyword(s):  
Social Media ◽  
Southeast Asia ◽  
Sperm Whale ◽  
The Philippines ◽  
Marine Debris ◽  
Cetacean Species ◽  
Marine Litter ◽  
Deep Diving ◽  
Marine Megafauna ◽  
The Impact

AbstractLitter in the marine environment, in particular plastic, is a significant threat to marine megafauna. Cetaceans are known to ingest or become entangled in marine debris, likely impacting individuals and populations. Southeast Asia is a biodiversity hotspot and harbours a diverse cetacean assemblage. However, there are key knowledge gaps relating to the impact of litter in this region due the lack of experts to survey its vast coastlines. This study aims to address such gaps by using social media, gathering data from Facebook posts relating to cetacean strandings and litter across Southeast Asia between 2009 and 2019. Results show that at least 15 cetacean species have been negatively affected by litter, with ingestion most commonly affecting deep-diving species. Epipelagic and mesopelagic foragers were most vulnerable to entanglement. Davao in the Philippines was identified as a litter-related stranding hotspot. The Irrawaddy dolphin (Orcaella brevirostris) and pygmy sperm whale (Kogia breviceps) are particularly vulnerable to litter. The combination of social media and peer reviewed literature can help build a more complete picture of the spatial distribution of marine litter and the scale of the impact it has on cetacean populations. In this study we provide details of a valuable online tool for helping to understand the impact of marine litter on cetaceans and other charismatic species that are a focus of community engagement.

Looking into a whale’s heart: investigating a genetic basis for cardiomyopathy in a non-model species

Genome ◽  
2017 ◽  
Vol 60 (8) ◽  
pp. 695-705
Author(s):  
Amélia Viricel ◽  
Patricia E. Rosel
Keyword(s):  
Mammalian Species ◽  
Mutation Screening ◽  
Sperm Whale ◽  
Muscle Disease ◽  
Control Group ◽  
Incomplete Penetrance ◽  
Model Species ◽  
Cetacean Species ◽  
Deep Diving ◽  
Age Related

Understanding the pathogenesis of complex diseases can benefit from multi-species comparative studies. Yet these studies rarely include natural populations of non-model species. Here, we focused on the cause of a heart muscle disease, cardiomyopathy (CM), affecting multiple mammalian species including humans, cats, dogs, and certain species of whales. Mutations in genes coding for sarcomeric proteins have been identified as a leading cause for CM in humans, and some were also revealed to be responsible for CM in cats. We investigated whether similar mutations could be detected in the deep-diving pygmy sperm whale (Kogia breviceps), which is one of two cetacean species known to display CM. We sequenced portions of two candidate genes (MYH7: 3153 bp and MYBPC3: 3019 bp) in 55 whales including affected and unaffected individuals. Mutation screening revealed six nonsynonymous substitutions that were predicted to have an effect on protein function. However, the etiology of CM is likely complex and probably multi-factorial as three of these mutations were observed in unaffected individuals from our control group. This incomplete penetrance could be partly age-related and could also be due to the influence of environmental factors on the development of CM, as seen in humans.

Stomach contents of cetaceans stranded in the Canary Islands 1996–2006

2009 ◽  
Vol 89 (5) ◽  
pp. 873-883 ◽  
Author(s):  
R. Fernández ◽  
M.B. Santos ◽  
M. Carrillo ◽  
M. Tejedor ◽  
G.J. Pierce
Keyword(s):  
Canary Islands ◽  
Stomach Contents ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Jaw Bones ◽  
Deep Diving ◽  
Fish Remains ◽  
Demersal Species ◽  
Belone Belone

Stomach contents were analysed from 23 cetaceans, including individuals of 12 species from the families Delphinidae, Physeteridae, Kogiidae and Ziphiidae, stranded between 1996 and 2006 in the Canary Islands. Cephalopod mandibles(beaks)were found in 21 stomachs and fish remains(otoliths and jaw bones)appeared in 4 stomachs. Two stomachs contained only eye lenses. Cephalopods eaten by dolphins were mainly from the families Ommastrephidae, Sepiidae and Enoploteuthidae, whereas whales had mainly taken specimens of the oceanic squid families Histiotheutidae and Cranchiidae. Fish remains included a pelagic species(i.e. garfish,Belone belone)in dolphin stomachs and bathypelagic(i.e. black scabbard fish,Aphanopus carbo, lantern fish,Lampadena luminosa)and demersal species(Lophiussp.)in a pygmy sperm whale(Kogia breviceps)stomach. Most of the prey species identified are not of commercial interest but one of the sperm whales(Physeter macrocephalus)contained a fishing hook among the stomach contents. Five(22%)of the cetaceans examined had also plastic debris in their stomachs, with big plastic items being taken by deep diving teuthophagous whales.

scholarly journals Echolocation click parameters and biosonar behaviour of the dwarf sperm whale (Kogia sima)

2021 ◽  
Vol 224 (6) ◽  
pp. jeb240689 ◽  
Author(s):  
Chloe E. Malinka ◽  
Pernille Tønnesen ◽  
Charlotte A. Dunn ◽  
Diane E. Claridge ◽  
Tess Gridley ◽  
...  
Keyword(s):  
Short Range ◽  
Narrow Band ◽  
Source Parameters ◽  
Sperm Whale ◽  
Sperm Whales ◽  
The Bahamas ◽  
Deep Diving ◽  
Close Range ◽  
Half Power ◽  
Kogia Sima

ABSTRACTDwarf sperm whales (Kogia sima) are small toothed whales that produce narrow-band high-frequency (NBHF) echolocation clicks. Such NBHF clicks, subject to high levels of acoustic absorption, are usually produced by small, shallow-diving odontocetes, such as porpoises, in keeping with their short-range echolocation and fast click rates. Here, we sought to address the problem of how the little-studied and deep-diving Kogia can hunt with NBHF clicks in the deep sea. Specifically, we tested the hypotheses that Kogia produce NBHF clicks with longer inter-click intervals (ICIs), higher directionality and higher source levels (SLs) compared with other NBHF species. We did this by deploying an autonomous deep-water vertical hydrophone array in the Bahamas, where no other NBHF species are present, and by taking opportunistic recordings of a close-range Kogia sima in a South African harbour. Parameters from on-axis clicks (n=46) in the deep revealed very narrow-band clicks (root mean squared bandwidth, BWRMS, of 3±1 kHz), with SLs of up to 197 dB re. 1 µPa peak-to-peak (μPapp) at 1 m, and a half-power beamwidth of 8.8 deg. Their ICIs (mode of 245 ms) were much longer than those of porpoises (<100 ms), suggesting an inspection range that is longer than detection ranges of single prey, perhaps to facilitate auditory streaming of a complex echo scene. On-axis clicks in the shallow harbour (n=870) had ICIs and SLs in keeping with source parameters of other NBHF cetaceans. Thus, in the deep, dwarf sperm whales use a directional, but short-range echolocation system with moderate SLs, suggesting a reliable mesopelagic prey habitat.

Valsalva retinopathy caused by deep diving

2020 ◽  
pp. 58-58
Author(s):  
M.V. Mustaeva-Pavlova ◽  
◽  
E.V. Molchanova ◽  
Keyword(s):  
Deep Diving ◽  
Valsalva Retinopathy

Актуальность. Ретинопатия Вальсальвы выявляется у больных при резком подъеме внутрибрюшного/внутригрудного давления в результате напряжения (маневра Вальсальвы), которое проявляется преимущественно преретинальным кровоизлиянием. Проявления могут возникнуть при глубоководных погружениях, поднятии тяжести, гипербарических пробах, аэробных упражнениях, кашле, рвоте, чихании, запорах. Цель. Обратить внимание офтальмологов на специфику данной патологии: развитие макулярного кровоизлияния вследствие повышения внутрибрюшного/внутригрудного давления, в результате напряжения. Материал и методы. Клинический случай: Пациентка, 14 лет, обратилась с жалобами на снижение зрения, «пятно» перед левым глазом после занятия плаванием, нырянием на глубину, обращение на вторые сутки. Объективно: VISOS = 0,5н/к. Глазное дно слева – кровоизлияние в центре макулярной области диаметром 1/4 PD. ОКТ: крупное, гиперэхогенное образование, во внутренних слоях сетчатки, h~183 мкм, утолщение сетчатки – h~306 мкм, в переднем отделе сетчатки кровоизлияние. Периметрия: центральная скотома левого глаза. Результаты. Через 9,5 месяцев выжидательной тактики: VISOS=1,0. На глазном дне кровоизлияние рассосалось, ОКТ левого глаза: гиперэхогенное образование h~25 мкм. Периметрия: поле зрения в норме. Выводы. Ретинопатия Вальсальвы — состояние, которое протекает благоприятно и не требует терапии. Дифференциальная диагностика должна проводиться с другими ретинопатиями, в том числе, с доброкачественной ретинопатией. Тщательный сбор анамнеза поможет в постановке диагноза и выборе тактики ведения пациента.

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