A recent discovery has revealed the ingenuity and social life of the Southern Resident killer whales, a population inhabiting the Salish Sea between Canada and the US. Through numerous drone recordings, scientists have documented how these cetaceans break off and modify kelp stalks to create tools with which they scratch and massage each other . This phenomenon, known as allokelping , has sparked international interest due to its originality and the depth of these animals' social bonds.
Until now, it was known that orcas and other whales play with algae or rub it on their skin, probably as a way to get rid of parasites and care for their skin . However, the documented behavior goes beyond simple play: orcas intentionally select, break, and adapt specific pieces of brown algae, which, thanks to their hose-like texture and slippery surface, are ideal for rubbing their skin without damaging it.
Experts have noted that males and females of all ages have been recorded engaging in allokelping , showing a clear preference for interacting with close relatives and individuals of similar age . On several occasions, the orcas twist and turn their bodies, holding the kelp between them for minutes to prolong contact, suggesting that this is a social activity involving mutual care.
Properties of algae and possible health function
Brown algae possess known antibacterial and anti-inflammatory properties , which may help orcas maintain healthy skin, facilitate the exfoliation of dead cells, and reduce discomfort caused by parasites. In addition to strengthening bonds within the pod, scientists suggest this behavior could serve a hygienic and therapeutic purpose.
This type of grooming has been documented for at least eight days during the recent study period, and all indications are that it is deeply rooted in the culture of this population . According to the researchers, it is a unique tradition that, should the southern resident population disappear, would vanish forever along with it.
An animal culture in serious danger
The resident killer whale population in the southern Salish Sea is listed as critically endangered . The last census in July 2024 counted only 73 individuals , a figure that worries experts and conservationists. Not only is their genetic diversity at risk, but also their way of life and social relationships.
The main threats facing these orcas include the scarcity of Chinook salmon , their primary food source, affected by overfishing and the destruction of river habitats, as well as underwater noise and industrial pollutants accumulating in the marine environment. Scientists also warn that the reduction of kelp forests, essential for social grooming, poses an additional risk stemming from global warming and rising water temperatures.
The discovery of this practice offers new insights into the complex social behavior of orcas and paves the way for further research into learning and the transmission of skills in other marine species. Experts emphasize the need to protect both orcas and the habitats and species they depend on, so that these traditions and ways of life are not lost in the ocean.
Observation using modern technologies, such as drones, is revealing unprecedented aspects of cetacean social life that were impossible to study until recently. The survival of this animal culture depends on urgent action to safeguard its fragile ecosystem and its primary food source.
Whale behavior demonstrates that natural behaviors are complex and can be vital for the health and social bonds of these animals. The transmission of traditions like allokelping highlights the importance of conservation efforts. Ensuring a healthy environment and abundant food sources is crucial for maintaining these social practices and preventing irreversible loss of this unique cultural knowledge.
