Study Finds Humpback Whales Use Sandy Bay Floors for Skin Care Routine
Rebecca West
Day spas for whales? Well, sort of. It's all about skincare. A new Griffith University study points to humpback whales using sandy, shallow bay areas to "roll" around in to remove dead skin cells while on their migratory trips south.
Research documenting whale behavior is relevant for conservation management and improved understanding of the species' habitat preferences.
Marine ecologist Dr. Olaf Meynecke, from the Griffith-led Whales and Climate Research Program and Coastal and Marine Research Centre, was able to track the humpbacks using suction cup tags during the creatures' southward migration from August 2021 to October 2022.
The tags are fitted with integrated high-definition video; a magnesium release system; a VHF transmitter for retrieval; magnetometers; a hydrophone; and light, pressure, temperature, and GPS sensors.
By utilizing data and video footage collected from the tags, the whales were seen performing full body and side rolls on the ocean floor, which is said to be lined with fine sand and rubble.
Meynecke noted, "On all occasions of sand rolling, the whales were observed on video to be slowly moving forward with their head first into the sand followed by rolling to one side or a full roll."
He continued by saying, "During the different deployments, the sand rolling was observed in the context of socializing. The behavior was either following courtship, competition, or other forms of socializing.
"So, we believe that the whales exfoliate using the sand to assist with molting and removal of ectoparasites, such as barnacles, and specifically select areas suitable for this behavior."
Whale barnacles are a species of acorn barnacle that belong to the family Coronulidae. They typically attach to baleen whales, and sometimes toothed whales, in the animal's early life stages. They need to remove them frequently to avoid excessive growth that leads to drag and energy loss, as they can end up being quite heavy over time.
"Humpback whales host diverse communities of skin bacteria that can pose a threat for open wounds if bacteria grow in large numbers," Meynecke further pointed out. "Removing excess skin is likely a necessity to maintain a healthy bacterial skin community. Humpback whales can remove some barnacles and skin through surface activity such as breaches but not all."
During the study, skin was seen sloughing off during the rolling process, and fish, like juvenile silver trevally, were observed actively feeding on it. For some reason, we're reminded of Kim Kardashian and her fish pedicures, but that's a whole other story.
The whales were tracked entering Gold Coast Bay, a shallow open embayment in southeast Queensland, Australia. The bottom substrate mainly consists of sand with some rocky reefs. It is an important aggregation site where humpback whales rest, socialize, and breed within 10 km of their migratory corridor during southern and northern migrations between June and October each year.
The research, entitled Exfoliating Whales–Sandy Bottom Contact Behaviour of Humpback Whales, has been published in Marine Science and Engineering.
To see them in action, check out the video.
https://youtu.be/i-txXu7tKpI
