A. Fahlman A. Fahlman R. S. Wells R. S. Wells N. West N. West A. Allen A. Allen A. Jabois A. Jabois T. Gallagher T. Gallagher J. Larsson J. Larsson E. Strom E. Strom Martina Mosing (Clinical Centre for Small Animal Health and Research, Clinical Department for Small Animals and Horses, Departments, University of Veterinary Medicine Vienna) Martina Mosing T. Harake T. Harake A. Adler A. Adler Company of Biologists 2026 Marine mammals possess specialized respiratory adaptations that enable efficient gas exchange and resilience to extreme pressures during diving, yet direct observation of lung mechanics under pressure has been logistically challenging. Electrical impedance tomography (EIT) measures real-time changes in thoracic impedance, and provides continuous, regional maps of pulmonary air distribution. We validated EIT for estimating tidal volume (VT) in bottlenose dolphins (Tursiops spp.) and Cape fur seals (Arctocephalus pusillus) both on land and in water. EIT reliably tracked VT in both taxa, showing strong within-trial consistency, with between-trial variability attributable to belt placement, body position and electrode contact. EIT also generated dynamic functional images of regional ventilation, revealing spatial and temporal patterns of lung filling and emptying. These results demonstrate that EIT is the first non-invasive imaging method validated for marine mammals in seawater, representing a critical step toward visualizing lung function during diving. PDFDocument eng 2026-08-07T08:56:39.540501211Z 2026 Spirometry Respiratory Monitoring Marine Mammal Cetacean Pinniped 3573172 b application/pdf http://creativecommons.org/licenses/by/4.0/