A new study published on July 15, 2025, in the journal Royal Society Open Science has shown that a group of wild bottlenose dolphins in Shark Bay, Australia, uses a special method to catch fish. These dolphins place marine sponges on their beaks to protect themselves while searching for food on the seafloor. The sponges are about the size of a softball or cantaloupe. Using the sponge, the dolphins dig through rocks and sand to find fish like the barred sandperch. This special hunting method is a form of cultural transmission because the dolphins learn it from their mothers. Only about 5% of the dolphins in Shark Bay, around 30 dolphins, use this hunting method. Scientists believe it is rare because it is difficult to learn.

Researchers found that the dolphins still use echolocation during sponge hunting. Echolocation is when dolphins send out sounds and listen for the echoes to find objects. However, the sponge causes a muffling effect, similar to wearing a mask. Marine biologist Ellen Rose Jacobs from the University of Aarhus in Denmark studied this by using underwater microphones and sound models. Even with this difficulty, the dolphins continue to catch food successfully. Experts say the technique shows the dolphins’ dexterity and learning abilities, as it requires years of practice and close observation of their mothers.