Dhaka, July 16 -- A small group of bottlenose dolphins in Shark Bay, Australia, has developed an unusual hunting method: using marine sponges as tools to catch fish. But new research shows that mastering this skill is far from easy.

The dolphins wear the sponge on their beaks like a protective mask, allowing them to dig through the seabed without injury and flush out fish like the elusive barred sandperch. This technique, passed down from mother to calf, disrupts the dolphin's echolocation abilities, making it harder to locate prey.

"It has a muffling effect, in the way that a mask might," explained Ellen Rose Jacobs, a marine biologist at Aarhus University and co-author of the study, published Tuesday in Royal Society Open Science. Des...