Certain dolphin populations in Australia have developed a unique foraging strategy. These dolphins utilize sea sponges, which they carry on their snouts, to protect themselves from sharp seabed rocks while searching for food. This behavior, passed down through generations, is a complex skill that requires adaptation.
Research published in Royal Society Open Science indicates that using a sponge on the snout can interfere with the dolphins’ echolocation abilities, which they rely on for navigation and hunting. Ellen Rose Jacobs,a marine biologist involved in the study,explained that the sponge acts as a “silencer,” similar to a mask,but dolphins can learn to compensate for this distortion.Jacobs used underwater microphones to confirm that dolphins in Shark Bay, Australia, continue to use echolocation clicks while employing this sponge-carrying technique. Her research also involved modeling the sound wave distortions caused by the sponges.
This sponge-assisted hunting method is highly effective for catching fish, though it presents challenges. Mauricio Cantor,a marine biologist not involved in the study,likened it to “hunting with bandaged eyes,” emphasizing the skill and training required. This difficulty may explain why only about 5% of the studied dolphin population in Shark Bay, approximately 30 individuals, engages in this practice.
Boris Worm, a marine ecologist also not involved in the study, noted that this specialized hunting ability has been learned over many years, and not all dolphins adopt it. Young dolphins typically spend several years with their mothers, observing and acquiring essential survival skills. Janet Mann, a co-author of the study and marine biologist, stated that the art of sponge hunting is “only transmitted from mother to breeding.”
