Orcas Caught Using Kelp in Affectionate Underwater Interactions

A fascinating and unexpected behavior among orcas was recently captured by scientists studying marine life in the Salish Sea, off the northwest coast of North America. Using drone footage, a team led by behavioral ecologist Michael Weiss recorded orcas rubbing pieces of seaweed on each other’s bodies — a behavior that stood out for both its frequency and tenderness.

At first, Weiss thought it was just another quirky moment from these playful animals. But upon closer inspection of the footage, he zoomed in and realized the orcas were intentionally using bull kelp, a common seaweed, to engage in these interactions.

Over the course of just two weeks in 2024, the team documented 30 separate instances of this behavior. The subjects were Southern Resident orcas, a distinct and closely studied population known for their strong social bonds and complex group dynamics.

The scientists coined the term “allokelping” for this behavior — combining “allo” (meaning “other”) and “kelping” (from “kelp”). It appears to serve dual purposes: helping with skin care — possibly removing parasites or dead skin — and strengthening social bonds through prolonged physical contact and cooperative play.

According to the study published in Current Biology, some of these sessions lasted up to 15 minutes, with the orcas rolling over one another and sharing the kelp in what looked like synchronized, playful movements — or perhaps even tender gestures.

The discovery adds to growing evidence that orcas are highly intelligent and emotionally complex beings, capable of sophisticated social interactions far beyond what earlier research imagined.

More than just a curious behavior, this newly observed interaction offers a rare glimpse into the emotional lives beneath the waves — reminding us that the ocean is home to deeply social creatures with rich and layered relationships.

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