Decompression sickness (`the bends`) in sea turtles
Investigation published in Diseases of Aquatic Organisms
October 16th, 2014
Decompression 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
Garcia-Parraga D., Crespo JL., De Quiros YB., Cervera V., Marti-Bonmati L., Diaz-Delgado J., Arbelo M., Moore MJ., Jepson PD. and Fernandez A.
 | Oceanogràfic. Ciudad de las Artes y las Ciencias. Generalitat Valenciana. |
 | Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
 | Instituto Universitario de Sanidad Animal y Seguridad Alimentaria (IUSA). Facultad de Veterinaria. Universidad de Las Palmas de Gran Canaria (ULPGC). |
| Hospital Veterinario Valencia Sur. | |
| Grupo de Investigación Biomédica en Imagen (GIBI230). Hospital Universitario y Politécnico La Fe. | |
| Radiology Department. Hospital Universitario y Politécnico La Fe. | |
| Department of Biology. Woods Hole Oceanographic Institution (WHOI). | |
| Zoological Society of London. Institute of Zoology (ZSL). | |
| Servicio de Inmunología Viral y Medicina Preventiva (SUAT). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
