Beach-safety drones flying over southeast Queensland, Australia, have revealed something lifeguards were not looking for: large, repeated gatherings of young scalloped hammerhead sharks, a species listed as critically endangered worldwide, in shallow water off two of the region's busiest beaches.

A study in Marine Biology analyzed four years of footage from Queensland's SharkSmart drone program and found groups of juvenile hammerheads at Burleigh Beach on the Gold Coast and Noosa Main Beach on the Sunshine Coast. Group sizes ranged from a single shark up to an estimated 100, with the biggest gatherings appearing between April and June.

The conservation stakes are sharp. The same two beaches sit inside Queensland's shark-control program, whose nets and baited drumlines have caught hundreds of scalloped hammerheads statewide over the past two decades, nearly all of which died.

Burleigh Headland Emerges as a Repeat Gathering Spot

Researchers led by Maddison Cross of the University of the Sunshine Coast and Queensland's Department of Primary Industries reviewed footage from 20,911 drone flights at nine beaches between September 2020 and December 2024. They recorded 84 hammerhead sighting events totaling 2,696 shark observations. Because the same animals were probably filmed more than once, that figure is not a count of individual sharks.

Most sightings came from Burleigh and Noosa, where hammerheads almost always appeared in groups. At the other seven beaches, the sharks were usually alone or in pairs. Median group sizes during the peak months of April, May and June were 55, 45 and 32.5 sharks, compared with two or fewer in every other month.

At Burleigh, the groups repeatedly used water near the rocky headland at the beach's southern end, with movement paths overlapping in both 2023 and 2024. The pattern at Noosa was less consistent. A gathering recorded there in 2023 did not appear during the same months in 2024, which the authors say could reflect a real change in habitat use or simply murkier water that hid the sharks from view.

The area's importance has already been recognized internationally. The study notes that the stretch of coast has since been designated the Burleigh-Kirra Important Shark and Ray Area by the IUCN shark specialist group.

Young Sharks, Not Newborns, and Not a Confirmed Nursery

Estimated lengths averaged about 1.09 meters (3.6 feet). Most sharks at Burleigh and Noosa were juveniles, a mix of first-year animals and sharks around one to two years old, according to the paper. They were not newborn pups, as ScienceAlert also noted in its coverage of the study.

That distinction matters. The researchers could not confirm that these beaches meet the scientific criteria for a shark nursery. Instead, they suggest the sites act as transitional habitat for young sharks moving out of sheltered estuaries and bays such as Moreton Bay as they grow. Nearby reefs, rocky areas and river outflows could supply prey, and swimming in groups may help juveniles avoid predators.

The authors argue the sites still "warrant precautionary management consideration" given repeated use by multiple age classes. They also acknowledge key gaps. Drones cannot reliably identify individual sharks, flights only ran in the morning, and the team could not tell how long the animals stayed or whether the same sharks returned each year. They recommend acoustic tagging to answer those questions.

Shark Nets Catch the Same Species Drones Are Revealing

Scalloped hammerheads have declined steeply worldwide, with loss estimates exceeding 80%, and the IUCN lists the species as critically endangered. In Australia, it is listed as conservation dependent under federal law and has been a no-take species in Queensland waters since 2024, according to the paper.

Burleigh Beach is protected by shark nets, while Noosa uses both nets and baited drumlines. Government records cited in the study show the program caught 675 scalloped hammerheads statewide between 2001 and 2024, and all but 10 were dead. At Burleigh and Noosa combined, 63 were caught in nets and two on drumlines.

Captures of juvenile hammerheads under 120 centimeters (about 3.9 feet) peak between September and February, while the drone gatherings peak from March to June. The authors suggest young sharks run into the gear as they move between sheltered nursery areas and the open coast, a finding that could inform when and where shark-control equipment poses the greatest risk to the species.

The issue is not unique to Australia. Scalloped hammerheads also live in U.S. waters from New Jersey to Florida, in the Gulf, off southern California and around Hawaii. NOAA Fisheries lists two population segments as endangered and two as threatened under the Endangered Species Act and notes that "they are threatened by commercial fishing, mainly for the shark fin trade."

Sharing the Water During Peak Season

The study did not assess shark-bite risk, and readers should not treat it as evidence that these beaches are more or less safe. The drone flights it relied on exist for public safety, and beachgoers should follow lifeguard instructions and any closures announced by Surf Life Saving Queensland or local councils.

What the study does address is disturbance. Some groups temporarily broke apart when snorkelers or paddleboarders approached, although those encounters were not systematically measured. The researchers list keeping a distance from the sharks and avoiding chasing or surrounding them among possible ways to reduce disruption, along with public education about the April-to-June gathering season. Drones flown at the program's standard height of at least 20 meters (66 feet) caused no visible reaction.

Visitors who spot a group of hammerheads should leave the water calmly if lifeguards advise it, report the sighting to patrol staff, and resist the urge to swim closer for photos. Large gatherings of a critically endangered species are rare — and the evidence suggests they are easily disturbed.

The bottom line: Queensland's beach drones have documented one of the few known juvenile hammerhead hot spots in Australian coastal waters, right beside popular surf breaks. The next questions, how long the sharks stay and where they go, will depend on tagging work the authors say is still needed — and on how managers weigh shark-control gear against the species' decline.

What Readers Want to Know

What did the drones find?

Drone footage from 2020 to 2024 showed groups of juvenile scalloped hammerhead sharks, up to an estimated 100 at a time, gathering off Burleigh Beach and Noosa Main Beach in southeast Queensland.

When do the gatherings happen?

The largest groups appeared between April and June, during Australia's autumn and early winter.

Are these sharks newborns?

No. Most were juveniles in their first or second year, averaging about 1.09 meters (3.6 feet) long. Researchers could not confirm the beaches are formal nursery areas.

Are the beaches dangerous for swimmers?

The study did not assess bite risk. Beachgoers should follow lifeguard instructions and any closures issued by Surf Life Saving Queensland or local councils.

Why are scalloped hammerheads endangered?

Global populations have fallen by more than 80%, mainly because of fishing. NOAA Fisheries cites commercial fishing for the shark fin trade as the main threat.

Do scalloped hammerheads live in U.S. waters?

Yes. NOAA Fisheries says they occur from New Jersey to Florida, in the Gulf, off southern California and around Hawaii, with four population segments listed under the Endangered Species Act.