New footage shows dolphins lining up for treatment for skin conditions at coral reef ‘clinics’, the behavior the researchers say is equivalent to a human shower after getting out of bed.
Clever mammals can be seen lining up nose to tail to scratch against outcroppings and the tactic has been detailed in a new study.
Researchers have now shown that corals have medicinal properties, suggesting that Indo-Pacific bottlenose dolphins use marine invertebrates to treat skin conditions.
Dr Angela Ziltener, a wildlife biologist at the University of Zurich in Switzerland, first observed dolphins brushing against coral in the northern Red Sea off the coast of Egypt about 13 years ago. years.
She and her team noticed that the dolphins were selective about which corals they rubbed against and wanted to find out why.
Dr. Ziltener, co-author of the study published in iSciencesaid: “I had never seen this coral rubbing behavior described before, and it was clear that the dolphins knew exactly which coral they wanted to use. I thought, ‘There must be a reason.’
Most dolphin research is conducted from the surface of the water, but because Dr. Ziltener is a diver, she was able to study dolphins up close.
It took a while to gain the pod’s trust, which she was able to do in part because the dolphins weren’t phased by the large bubbles released by her air tank.
Dr Ziltener said: “Some dolphins, such as spinner dolphins in the southern Egyptian Red Sea, are more bubble shy.”
Once the pod allowed her to visit them regularly, she and her colleagues were able to identify and sample the corals the dolphins were using.
Dr. Ziltener and his team found that by repeatedly rubbing against corals, Indo-Pacific bottlenose dolphins wiggle the tiny polyps that make up the coral community, and these invertebrates release mucus.
To understand the properties contained in the mucus, the team took samples of coral.
When the study’s lead author, Professor Gertrud Morlock, and his team used state-of-the-art equipment to analyze samples of gorgonian coral Rumphella aggregateatacoral leather Sarcophyton sp. and the sponge Ircinia sp. they found 17 active metabolites with antibacterial, antioxidant, hormonal and toxic activities.
This discovery of the bioactive compounds led the team to believe that mucus from corals and sponges serves to regulate the dolphins’ skin microbiome and treat infections.
Professor Morlock, an analytical chemist and food scientist at Justus Liebig University in Germany, said: ‘Repeated rubbing allows active metabolites to come into contact with the skin of dolphins.
“These metabolites might help them achieve skin homeostasis and be useful for prophylaxis or adjunctive therapy against microbial infections.”
The reefs where the corals are found are important places for local dolphin populations, according to Dr. Ziltener.
She said: “They go there to rest and have fun. Many people don’t realize that these coral reefs are dolphins’ rooms and also playgrounds.
Between naps, Dr. Ziltener says dolphins often wake up to perform coral rubbing behavior.
She said: “It’s almost like they shower, clean up before going to sleep or getting up for the day.”
But since she began her research on dolphins in Egypt in 2009, Dr Ziltener has noticed a disturbing trend.
She said: “The tourism industry is now making a lot of money from swimming with dolphins. People dream of swimming with dolphins, so they determine which reefs they use and bother the dolphins if they don’t follow the guidelines on how to approach them responsibly.
Dr Ziltener said she was so concerned that she started an organization called the Dolphin Watch Alliance, a conservation group that educates tour guides, tourists and the public on how to provide tourists with safe experiences for dolphins, and lobbied for the reefs to become protected areas.