Bottlenose dolphins in Queensland’s Great Sandy Marine Park have been documented using large sea snail shells to trap fish, marking the first published scientific record of this rare tool-use behavior on Australia’s east coast. According to research published in Marine Mammal Science by scientists at the University of the Sunshine Coast, the tactic—known as “shelling”—involves chasing a fish into an empty shell, lifting it to the water’s surface, and shaking it upside down to direct the meal into the dolphin’s mouth.
How Researchers Documented East Coast Shelling
University of the Sunshine Coast researchers recorded two separate sightings of bottlenose dolphins engaging in shelling between July and October 2025. Dr. Alexis Levengood, an animal behaviorist and lead author of the study, described the moment the team spotted the marine mammals in action off Hervey Bay. “We were on a research boat off Hervey Bay when we spotted a dolphin raising something large out of the water,” Dr. Levengood stated, adding, “I started screaming because I know what shelling looks like.” While local operators with Blue Dolphin Marine Tours previously reported observing the behavior in 2013 and 2019, those earlier accounts lacked formal scientific documentation.
Challenging Assumptions About Marine Mammal Learning
The recent findings offer potential evidence of maternal social transmission in dolphins, challenging long-held assumptions about how marine mammals acquire tool use. During the observations, an adult female dolphin and her calf were seen performing the behavior together. According to researchers, the mother surfaced with a shell, the fish escaped, and the dolphin dropped the shell. Minutes later, the calf picked up the shell and held it in the exact same manner as the mother. Previously, scientists believed dolphins learned shelling primarily through horizontal or vertical peer learning by watching members of their social network rather than through direct maternal instruction.
Comparing Australian Dolphin Populations
Before this study, the only published evidence of dolphin shelling came from Shark Bay in Western Australia, located over 3,000 kilometers away. The new documentation from Queensland proves that dolphin populations on opposite sides of the continent independently developed the exact same complex foraging strategy. Researchers emphasize that studying these regional behaviors helps science better understand cognitive evolution and innovation in non-human animals.
Did You Know?
Frequently Asked Questions
What is dolphin “shelling”?
Shelling is a rare foraging behavior where bottlenose dolphins chase fish into empty sea snail shells, lift the shells out of the water, and shake them to empty the trapped fish directly into their mouths.
Where was this behavior documented?
According to the University of the Sunshine Coast study, researchers documented the behavior in the Great Sandy Marine Park off Hervey Bay, Queensland, marking the first published record on Australia’s east coast.
How do young dolphins learn to use tools?
While scientists previously thought dolphins learned shelling primarily from peers, recent footage of a calf mimicking its mother suggests that maternal social transmission may also play a role.
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