Dolphins were first spotted in carrying sponges in their mouths in 1984 at Shark Bay, Western Australia.It is believed they do it to protect their noses while they forage for food along the rocky ocean floor.
It has remained a mystery why only 5% of the bay’s population use this technique. After observing the mammals for four years, a researcher has found it is only passed down from mother to daughter. Males prefer to gather in packs to hunt together and socialise.
Computer modelling was used to draw estimates on when the technique originated. It is believed the dolphins began its use up to 180 years ago and have passed it down through eight generations.