Fernandez
Antonio
Fernandez
Antonio
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ArticleDecompression sickness (‘the bends’) in sea turtles(Inter-Research, 2014-10-16) Garcia-Parraga, Daniel ; Crespo-Picazo, J. L. ; Bernaldo de Quiros, Yara ; Cervera, V. ; Marti-Bonmati, L. ; Diaz-Delgado, J. ; Arbelo, Manuel ; Moore, Michael J. ; Jepson, Paul D. ; Fernandez, AntonioDecompression sickness (DCS), as clinically diagnosed by reversal of symptoms with recompression, has never been reported in aquatic breath-hold diving vertebrates despite the occurrence of tissue gas tensions sufficient for bubble formation and injury in terrestrial animals. Similarly to diving mammals, sea turtles manage gas exchange and decompression through anatomical, physiological, and behavioral adaptations. In the former group, DCS-like lesions have been observed on necropsies following behavioral disturbance such as high-powered acoustic sources (e.g. active sonar) and in bycaught animals. In sea turtles, in spite of abundant literature on diving physiology and bycatch interference, this is the first report of DCS-like symptoms and lesions. We diagnosed a clinico-pathological condition consistent with DCS in 29 gas-embolized loggerhead sea turtles Caretta caretta from a sample of 67. Fifty-nine were recovered alive and 8 had recently died following bycatch in trawls and gillnets of local fisheries from the east coast of Spain. Gas embolization and distribution in vital organs were evaluated through conventional radiography, computed tomography, and ultrasound. Additionally, positive response following repressurization was clinically observed in 2 live affected turtles. Gas embolism was also observed postmortem in carcasses and tissues as described in cetaceans and human divers. Compositional gas analysis of intravascular bubbles was consistent with DCS. Definitive diagnosis of DCS in sea turtles opens a new era for research in sea turtle diving physiology, conservation, and bycatch impact mitigation, as well as for comparative studies in other air-breathing marine vertebrates and human divers.
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ArticleDeadly diving? Physiological and behavioural management of decompression stress in diving mammals(Royal Society, 2011-12-21) Hooker, Sascha K. ; Fahlman, Andreas ; Moore, Michael J. ; Aguilar De Soto, Natacha ; Bernaldo de Quiros, Yara ; Brubakk, A. O. ; Costa, Daniel P. ; Costidis, Alexander M. ; Dennison, Sophie ; Falke, K. J. ; Fernandez, Antonio ; Ferrigno, Massimo ; Fitz-Clarke, J. R. ; Garner, Michael M. ; Houser, Dorian S. ; Jepson, Paul D. ; Ketten, Darlene R. ; Kvadsheim, P. H. ; Madsen, Peter T. ; Pollock, N. W. ; Rotstein, David S. ; Rowles, Teresa K. ; Simmons, S. E. ; Van Bonn, William ; Weathersby, P. K. ; Weise, Michael ; Williams, Terrie M. ; Tyack, Peter L.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 (N2) 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 N2 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 N2 loading to management of the N2 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.
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ArticleDecompression vs. decomposition : distribution, amount, and gas composition of bubbles in stranded marine mammals(Frontiers Media, 2012-06-04) Bernaldo de Quiros, Yara ; Gonzaez-Diaz, Oscar ; Arbelo, Manuel ; Sierra, Eva ; Sacchini, Simona ; Fernandez, AntonioGas embolic lesions linked to military sonar have been described in stranded cetaceans including beaked whales. These descriptions suggest that gas bubbles in marine mammal tissues may be more common than previously thought. In this study we have analyzed gas amount (by gas score) and gas composition within different decomposition codes using a standardized methodology. This broad study has allowed us to explore species-specific variability in bubble prevalence, amount, distribution, and composition, as well as masking of bubble content by putrefaction gases. Bubbles detected within the cardiovascular system and other tissues related to both pre- and port-mortem processes are a common finding on necropsy of stranded cetaceans. To minimize masking by putrefaction gases, necropsy, and gas sampling must be performed as soon as possible. Before 24 h post mortem is recommended but preferably within 12 h post mortem. At necropsy, amount of bubbles (gas score) in decomposition code 2 in stranded cetaceans was found to be more important than merely presence vs. absence of bubbles from a pathological point of view. Deep divers presented higher abundance of gas bubbles, mainly composed of 70% nitrogen and 30% CO2, suggesting a higher predisposition of these species to suffer from decompression-related gas embolism.