“Gas and Fat Embolic Syndrome” Involving a Mass Stranding of Beaked Whales (Family Ziphiidae) Exposed to Anthropogenic Sonar Signals

2005 ◽  
Vol 42 (4) ◽  
pp. 446-457 ◽  
Author(s):  
A. Fernández ◽  
J. F. Edwards ◽  
F. Rodríguez ◽  
A. Espinosa de los Monteros ◽  
P. Herráez ◽  
...  
Keyword(s):  
Canary Islands ◽  
Marine Mammals ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Fat Embolism ◽  
Diving Behavior ◽  
Associated Lesions ◽  
Beaked Whales ◽  
Mass Stranding

A study of the lesions of beaked whales (BWs) in a recent mass stranding in the Canary Islands following naval exercises provides a possible explanation of the relationship between anthropogenic, acoustic (sonar) activities and the stranding and death of marine mammals. Fourteen BWs were stranded in the Canary Islands close to the site of an international naval exercise (Neo-Tapon 2002) held on 24 September 2002. Strandings began about 4 hours after the onset of midfrequency sonar activity. Eight Cuvier's BWs (Ziphius cavirostris), one Blainville's BW (Mesoplodon densirostris), and one Gervais' BW (Mesoplodon europaeus) were examined postmortem and studied histopathologically. No inflammatory or neoplastic processes were noted, and no pathogens were identified. Macroscopically, whales had severe, diffuse congestion and hemorrhage, especially around the acoustic jaw fat, ears, brain, and kidneys. Gas bubble-associated lesions and fat embolism were observed in the vessels and parenchyma of vital organs. In vivo bubble formation associated with sonar exposure that may have been exacerbated by modified diving behavior caused nitrogen supersaturation above a threshold value normally tolerated by the tissues (as occurs in decompression sickness). Alternatively, the effect that sonar has on tissues that have been supersaturated with nitrogen gas could be such that it lowers the threshold for the expansion of in vivo bubble precursors (gas nuclei). Exclusively or in combination, these mechanisms may enhance and maintain bubble growth or initiate embolism. Severely injured whales died or became stranded and died due to cardiovascular collapse during beaching. The present study demonstrates a new pathologic entity in cetaceans. The syndrome is apparently induced by exposure to mid-frequency sonar signals and particularly affects deep, long-duration, repetitive-diving species like BWs.

scholarly journals Bubbles in live-stranded dolphins

2011 ◽  
Vol 279 (1732) ◽  
pp. 1396-1404 ◽  
Author(s):  
S. Dennison ◽  
M. J. Moore ◽  
A. Fahlman ◽  
K. Moore ◽  
S. Sharp ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Post Mortem ◽  
Health Assessments ◽  
In The Wild ◽  
Beaked Whales ◽  
Clinically Significant ◽  
Probable Origin ◽  
Hepatic Portal

Bubbles in supersaturated tissues and blood occur in beaked whales stranded near sonar exercises, and post-mortem in dolphins bycaught at depth and then hauled to the surface. To evaluate live dolphins for bubbles, liver, kidneys, eyes and blubber–muscle interface of live-stranded and capture-release dolphins were scanned with B-mode ultrasound. Gas was identified in kidneys of 21 of 22 live-stranded dolphins and in the hepatic portal vasculature of 2 of 22. Nine then died or were euthanized and bubble presence corroborated by computer tomography and necropsy, 13 were released of which all but two did not re-strand. Bubbles were not detected in 20 live wild dolphins examined during health assessments in shallow water. Off-gassing of supersaturated blood and tissues was the most probable origin for the gas bubbles. In contrast to marine mammals repeatedly diving in the wild, stranded animals are unable to recompress by diving, and thus may retain bubbles. Since the majority of beached dolphins released did not re-strand it also suggests that minor bubble formation is tolerated and will not lead to clinically significant decompression sickness.

scholarly journals Advances in research on the impacts of anti-submarine sonar on beaked whales

2019 ◽  
Vol 286 (1895) ◽  
pp. 20182533 ◽  
Author(s):  
Y. Bernaldo de Quirós ◽  
A. Fernandez ◽  
R. W. Baird ◽  
R. L. Brownell ◽  
N. Aguilar de Soto ◽  
...  
Keyword(s):  
Canary Islands ◽  
Decompression Sickness ◽  
Current Knowledge ◽  
Population Level ◽  
Mitigation Measures ◽  
Individual Outcomes ◽  
Spatial Management ◽  
Level Information ◽  
Beaked Whales ◽  
The 1960S

Mass stranding events (MSEs) of beaked whales (BWs) were extremely rare prior to the 1960s but increased markedly after the development of naval mid-frequency active sonar (MFAS). The temporal and spatial associations between atypical BW MSEs and naval exercises were first observed in the Canary Islands, Spain, in the mid-1980s. Further research on BWs stranded in association with naval exercises demonstrated pathological findings consistent with decompression sickness (DCS). A 2004 ban on MFASs around the Canary Islands successfully prevented additional BW MSEs in the region, but atypical MSEs have continued in other places of the world, especially in the Mediterranean Sea, with examined individuals showing DCS. A workshop held in Fuerteventura, Canary Islands, in September 2017 reviewed current knowledge on BW atypical MSEs associated with MFAS. Our review suggests that the effects of MFAS on BWs vary among individuals or populations, and predisposing factors may contribute to individual outcomes. Spatial management specific to BW habitat, such as the MFAS ban in the Canary Islands, has proven to be an effective mitigation tool and mitigation measures should be established in other areas taking into consideration known population-level information.

Supersaturation by counterperfusion and diffusion of gases

1977 ◽  
Vol 42 (5) ◽  
pp. 758-760 ◽  
Author(s):  
B. A. Hills
Keyword(s):  
Steady State ◽  
Diffusion Barrier ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Inert Gases ◽  
And Diffusion ◽  
Diffusion Of Gases

Gaseous supersaturation can be induced under steady-state conditions when two inert gases are transmitted in opposite directions across any system comprising a diffusion barrier adjacent to a zone of limited convective capacity. This has many implications for bubble formation in vivo and can explain the occurence of symptoms of decompression sickness without decompression.

scholarly journals Deadly diving? Physiological and behavioural management of decompression stress in diving mammals

2011 ◽  
Vol 279 (1731) ◽  
pp. 1041-1050 ◽  
Author(s):  
S. K. Hooker ◽  
A. Fahlman ◽  
M. J. Moore ◽  
N. Aguilar de Soto ◽  
Y. Bernaldo de Quirós ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Multiple Stressors ◽  
Decompression Sickness ◽  
Tissue Injury ◽  
Bubble Formation ◽  
Gas Bubbles ◽  
Breath Hold ◽  
Technological Advances ◽  
Measured Time

Decompression sickness (DCS; ‘the bends’) is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N 2 ) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N 2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N 2 loading to management of the N 2 load . This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.

scholarly journals Evidence for the initiation of decompression sickness by exposure to intense underwater sound

2015 ◽  
Vol 114 (3) ◽  
pp. 1521-1529 ◽  
Author(s):  
Dror Tal ◽  
Hofit Shachar-Bener ◽  
Dov Hershkovitz ◽  
Yehuda Arieli ◽  
Avi Shupak
Keyword(s):  
Decompression Sickness ◽  
Close Association ◽  
Ambient Pressure ◽  
Sound Field ◽  
Underwater Sound ◽  
Neurological Damage ◽  
Associated Lesions ◽  
Sonar Systems ◽  
Decompression Stress ◽  
Mass Stranding

Mass stranding of cetaceans (whales and dolphins), in close association with the activity of naval sonar systems, has been reported on numerous occasions. Necropsy showed bubble-associated lesions similar to those described in human decompression sickness (DCS). We examined the hypothesis that exposure to underwater sound may potentiate DCS. Rats were subjected to immersion and simulated dives with and without simultaneous acoustic transmissions at pressure levels and frequencies of 204 dB/8 kHz and 183.3 dB/15 kHz. DCS severity was assessed using the rotating wheel method. Recording of somatosensory evoked potentials (SSEPs) was employed under general anesthesia as an electrophysiological measure of neurologic insult. A significantly higher rate of decompression sickness was found among animals exposed to the 204-dB/8-kHz sound field. Significantly higher pathological SSEPs scores were noted for both underwater sound protocols. Pathological SSEPs scores in animals immersed during the acoustic transmissions, but without changes in ambient pressure, were comparable to those observed in animals exposed to the dive profile. The results demonstrate induction of neurological damage by intense underwater sound during immersion, with a further deleterious effect when this was combined with decompression stress. The study outcome has potential implications for human diving safety and may provide an explanation for the mass stranding of cetaceans purportedly associated with sonar activity.

Production of gas bubbles in fluids by tribonucleation

1970 ◽  
Vol 28 (4) ◽  
pp. 524-527 ◽  
Author(s):  
Kenneth G. Ikels
Keyword(s):  
Decompression Sickness ◽  
Bubble Formation ◽  
Gas Bubbles ◽  
Glass Tube ◽  
Dissolved Gas ◽  
Experimental Conditions ◽  
Gas Concentration ◽  
Solid Bodies

This report describes a mechanism, called tribonucleation, for producing gas nuclei by making and breaking contact between solid bodies which are immersed in liquid. A metal ball was rolled inside a glass tube filled with liquid which contains dissolved gas. Formed nuclei may grow to visible bubbles depending on the dissolved gas concentration and pressure applied to the liquid. Unlike other possible mechanisms for forming bubbles, tribonucleation is capable of producing nuclei under relatively mild experimental conditions, such as may be encountered in vivo. The experiments show that viscosity and velocity of separation of surfaces are important determinants of whether or not nuclei will form. bubble formation; decompression sickness Submitted on August 20, 1969

scholarly journals Insights into the diet of beaked whales from the atypical mass stranding in the Canary Islands in September 2002

2007 ◽  
Vol 87 (1) ◽  
pp. 243-251 ◽  
Author(s):  
M.B. Santos ◽  
V. Martin ◽  
M. Arbelo ◽  
A. Fernández ◽  
G.J. Pierce
Keyword(s):  
Canary Islands ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Published Data ◽  
Beaked Whale ◽  
Cephalopod Species ◽  
Beaked Whales ◽  
Ziphius Cavirostris ◽  
Prey Remains ◽  
Mass Stranding

Stomach contents were analysed from three species of beaked whales which mass-stranded shortly after a naval exercise conducted in the Canary Islands in September 2002. Animals from such mass strandings often contain freshly ingested food in their stomachs and can provide a more reliable guide to feeding habits than other strandings. Food remains recovered from seven Cuvier's beaked whales (Ziphius cavirostris) consisted mainly of oceanic cephalopods, the most numerous being Taonius pavo, Histioteuthis sp., Mastigoteuthis schmidti and Octopoteuthis sicula. Many of the cephalopod species found in the diet appear to undertake daily vertical migrations, being found in shallower waters during the night and moving to deeper waters during the day. Single specimens of Blainville's beaked whale (Mesoplodon densirostris) and Gervais' beaked whale (Mesoplodon europaeus) had eaten both fish and cephalopod prey. The most numerous prey remains belonged to gadid fish and viperfish (Chauliodus sp.) respectively. These results are consistent with the limited published data on diet in these species, with Mesoplodon species having a relatively higher proportion of fish in the diet whereas Ziphius specialises on cephalopods.

Hyperbaric treatment of air or gas embolism: current recommendations

2019 ◽  
pp. 673-683
Author(s):  
Richard E. Moon ◽  
Keyword(s):  
Animal Studies ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Endothelial Damage ◽  
Neurological Deficits ◽  
Breath Hold ◽  
Gas Embolism ◽  
Hyperbaric Treatment ◽  
Pulmonary Capillaries ◽  
Venous Gas Embolism

Gas can enter arteries (arterial gas embolism, AGE) due to alveolar-capillary disruption (caused by pulmonary over-pressurization, e.g. breath-hold ascent by divers) or veins (venous gas embolism, VGE) as a result of tissue bubble formation due to decompression (diving, altitude exposure) or during certain surgical procedures where capillary hydrostatic pressure at the incision site is subatmospheric. Both AGE and VGE can be caused by iatrogenic gas injection. AGE usually produces stroke-like manifestations, such as impaired consciousness, confusion, seizures and focal neurological deficits. Small amounts of VGE are often tolerated due to filtration by pulmonary capillaries; however VGE can cause pulmonary edema, cardiac “vapor lock” and AGE due to transpulmonary passage or right-to-left shunt through a patient foramen ovale. Intravascular gas can cause arterial obstruction or endothelial damage and secondary vasospasm and capillary leak. Vascular gas is frequently not visible with radiographic imaging, which should not be used to exclude the diagnosis of AGE. Isolated VGE usually requires no treatment; AGE treatment is similar to decompression sickness (DCS), with first aid oxygen then hyperbaric oxygen. Although cerebral AGE (CAGE) often causes intracranial hypertension, animal studies have failed to demonstrate a benefit of induced hypocapnia. An evidence-based review of adjunctive therapies is presented.

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

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.

Sign in / Sign up

Export Citation Format

Share Document