Overview
- Researchers published findings July 23–24, 2026 after attaching suction-cup tags to 42 sperm whales off Norway to record bubble sounds and 3-D movement.
- Tag data combined with physics-based simulations show whales release gas from their respiratory system while resting to reduce the strong positive buoyancy caused by spermaceti oil in their heads.
- Whales resting near the surface produced far more bubbles per nap (about 11) than those rising from depth (about 3–4), a pattern consistent with pressure compressing lung gas at greater depth.
- The team cannot yet say whether bubble release is a controlled, conscious action or an automatic physiological response tied to the sleep state, and the data come from a single Norwegian field site.
- The result explains how sperm whales maintain a rare vertical sleeping posture, suggests links to metabolic off-gassing of dissolved gases, and points to new questions about cetacean sleep and buoyancy control for future study.