Overview

• Researchers documented around 30 cases of whales biting and trimming bull kelp to roll between their bodies in a behavior termed "allokelping".
• Observations from spring and summer 2024 show individuals of all ages and pods performing kelp-assisted grooming on most drone flights, indicating widespread cultural transmission.
• Whales with heavier dead skin loads engage more frequently in allokelping, suggesting the kelp acts as an aquatic brush for hygiene.
• This discovery marks the first confirmed instance of manufacturing and using tools by any marine mammal, expanding knowledge of cetacean cognition and culture.
• With fewer than 80 southern residents remaining and kelp forests shrinking from warming seas, experts warn the unique grooming practice risks disappearing without targeted conservation.