Whale ’kelping’: humpbacks’ playful seaweed interactions revealed worldwide

Griffith University researchers found that migrating humpback whales across the globe are using seaweed to play and roll in its anti-bacterial properties. The behaviour, known as ‘kelping’, was documented in over 100 instances through unmanned-aerial-vehicle (UAV) observations and social media documentations. Published in the open-access journal JMSE, the study examines the understudied ‘kelping’ behaviour in baleen whales, including humpbacks, across northern and southern hemisphere populations. The researchers observed these whales rolling and engaging in what seemed like playful interactions with clumps of kelp and seaweed at the water’s surface. The cognitive abilities of whales is widely acknowledged, leading to complex interactions and feeding strategies. Cetaceans frequently engage in playful ways, indicating innovation and creativity. However, until now, little is known about these behaviours in baleen whales, primary filter-feeders. Reports of such interactions with seaweed remain largely anecdotal, with limited research focused on this behaviour to date. The researchers highlight the consistent nature of the observed ’kelping’ behaviour across various locations worldwide The observed ‘kelping’ behaviour was analysed via aerial observations in three instances on Australia’s east coast by author on the paper, Dr Olaf Meynecke. These observations complemented over 100 unrelated instances of seaweed interactions documented globally through social media content, strengthening the research findings. In the study, the researchers found consistent seaweed interactions among baleen whales across regions, primarily involving the rostrum (their flat upper head) and dorsal fin. Dr Meynecke had previously observed whales rolling in sandy substrates off the Gold Coast, Australia, suggesting it might help remove dead skin cells and parasites during their migrations. “The use of objects by cetaceans like baleen whales is well known, and their ability to interact with their environment in complex behaviours has been previously reported on,” Dr Meynecke says. “But baleen whales, including humpback whales, are less often observed to perform object use, and this behaviour might be more common than previously thought.” In the study, Dr Meynecke and co-author, Hilla Kela, note how only a few isolated observations of interactions with seaweed have been reported in the scientific literature to date. They attribute these new findings to the recovery of humpback whale populations and advancements in technology, such as UAVs and social media, enabling a new assessment of baleen whale interactions with objects. Dr Meynecke explains how “There are two plausible theories: play and/or self-medication with seaweed. This behaviour may be playful but could also serve additional benefits in the context of learning and socialising, as well as ectoparasite removal and skin treatment by using brown algae’s antibacterial properties.” Among the documented interactions, 163 baleen whales were observed, with humpback whales being the most prevalent, accounting for 95 separate events. Gray whales and southern right whales were observed twice each, while northern right whales were observed once. Adult species formed the largest group of interactions at 53 percent, followed by a documented 14 percent of calves, and 1 percent of subadults, leaving 32 percent at an unidentified size. Is it play behaviour, a health benefit akin to a spa treatment or facial mask for us humans, or something else entirely? That’s where further research into these behaviours will help to deduce these observations, with much still to learn about cetacean behaviour. Dr Meynecke explains that identifying this type of behaviour across different baleen whale populations is important to better understand wider species behaviours, habitat preference and movements - all critical knowledge to cetacean research. If you’re interested in learning more about this research, you can access the paper published in JMSE here: