Slide 1
A seal dives using oxygen stored before submerging
A seal is a mammal that breathes air. During an underwater hunt, it relies on oxygen already stored in its body.
More to Read
Its lungs are only part of that supply. Blood and muscles hold substantial oxygen, helping explain why comparing lung size alone would miss much of its diving capacity.
Slide 2
Myoglobin holds an oxygen reserve in muscle
Myoglobin is a protein that holds oxygen in muscle. Diving seals can have rich muscle oxygen stores for underwater activity.
More to Read
Haemoglobin carries oxygen in blood, while myoglobin serves a different location. Distinguishing the proteins makes the reserve easier to understand without treating all body oxygen as one tank.
Slide 3
Gliding spends less energy than active stroking
A seal can reduce expenditure by gliding during parts of a dive. Less active stroking means less energy needed for movement.
More to Read
Buoyancy changes as air spaces compress with depth. The balance between swimming and gliding can therefore change along the route rather than remaining fixed throughout the dive.
Slide 4
The oxygen budget limits the underwater hunt
Dive duration depends on both oxygen supply and how quickly it is used. Hunting effort changes the time available underwater.
More to Read
A record-long dive is not necessarily a routine feeding dive. Researchers need ordinary behaviour data to understand how an animal usually balances travel, searching and recovery.
Slide 5
Tracking instruments reveal the dives from below the surface
Animal-borne instruments record depth and movement during seal dives. They reveal activity hidden from observers waiting at the surface.
More to Read
Video can show whether movement signals correspond to swimming, gliding or prey encounters. Combining measurements links a physiological explanation to the behaviour actually performed at sea.
Sources
- Breath Hold
UC Santa Cruz Williams Lab
- Video reveals marine mammals laid-back while deep diving
UC Santa Cruz