Dolphin Lung Collapse and Intramuscular Circulation During Free Diving: Evidence from Nitrogen Washout

Intramuscular nitrogen tensions in Tursiops truncatus after a schedule of repetitive ocean dives suggest a lung collapse depth of about 70 meters and suggest that intramuscular circulation is maintained during unrestrained diving in the open ocean. Therefore, the bottle-nosed dolphin is not protected by lung collapse from the decompression hazards of dives to depths shallower than 70 meters.