How drones shed light on the secret lives of great white sharks

“CAUTION,” reads the bright yellow sign firmly planted in the sand. “DRONE ACTIVITY IN PROGRESS.”

People gather around the sign, eyes darting between it and the people standing near it in matching jerseys to solidify that they are a team. The chatter starts to get louder as people ask aloud why they’re there, what they see, what’s going on. The drone pilot ignores them, busy. concentrating. Instead, his team asks bystanders to stand back and not shout questions at the drone pilot: they’re working. The person laser-focused on the remote control monitor in his hands isn’t shooting the next viral Instagram Reel or TikTok video… he’s looking for sharks.

Unmanned aerial vehicles, often known as drones, are an emerging surveillance technology that provides aerial surveillance of coastal waters and real-time viewing of the area. More and more beaches are implementing the use of drones to keep boaters safe from not only sharks, but other potential dangers as well. Thanks to technology, it seems like we are seeing sharks more than ever as drone operators around the world upload their footage to various social media platforms. While these videos show that these predators tend to ignore us (unless they are being chased or harassed), there are hundreds of hours of unseen footage online that is being used to inform authorities’ decisions about handling the beach.

“[Drone] the technology has really revolutionized and given us a whole different view of sharks,” Chris Lowe, professor of marine biology and director of the Shark Lab at California State University, Long Beach, told The Verge. He went on to explain that before drones, scientists had to rely on planes and helicopters to conduct aerial surveys of sharks. It was expensive and clearly something you couldn’t do every day. A much cheaper alternative enters, the drone. Video footage from drones can and has been used to quantify the morphology and behavior of sharks in shallow marine environments, and a new study has done just that… with a twist.

The movement patterns and behavior of white sharks in nearshore waters are mostly predictable under normal conditions until you add stranded whale carcasses to the equation. Numerous whale populations are recovering around the world thanks to protection measures put in place, however that means the number of stranded whale carcasses has increased on remote and popular beaches. Led by scientist James P. Tucker of the National Center for Marine Sciences at Southern Cross University in Australia, a team set out to see how whale carcasses influence the numbers and behavior of potentially dangerous sharks in the vicinity of whales. strandings. white sharks (Carcharodon carcharias) are present in varying numbers throughout the year here, and there are multiple records of them scavenging on floating whale carcasses. Also known as ‘white pointer’ in Australia, it is the largest predatory fish on Earth. They are found in cold coastal waters around the world and are an elusive marine predator. Fortunately, since drones are not as expensive as traditional aerial surveys, the researchers were able to easily observe great whites along the New South Wales (NSW) coast.

There are not only great whites on the NSW coast. Some species of whales, such as Bryde’s whales (Balaenoptera brydei), are permanent residents of these waters, while other species, such as humpback whales (Megaptera novaeangliae), migrate annually. The researchers were able to collect drone-based video footage of great white sharks at four separate whale carcass stranding events, which included two humpback whales, one fin whale (Balaenoptera physalus), and a sperm whale (Physeter macrocephaly); they also compared their findings to those of another dataset that collected similar drone-based data on white sharks at nearby beaches without whale carcasses from September 2016 to October 2018. “Comparing these two datasets, [we were able] to test hypotheses about white shark behavior change near beached whale carcasses,” the authors explained.

After analyzing all the images, the team found that the great white shark’s behavior was significantly altered by the presence of a beached whale carcass. Differences were observed in the speed, length, straightness and sinuosity of the white shark’s movements. “These differences are relevant to shark risk management on beaches because they indicate increased shark interest in locations close to stranded carcasses, and therefore should be taken into account when developing whale stranding management plans and decide when it is appropriate to enforce beach closures,” the authors said. .

The message is clear: if there’s a whale carcass in the area, it’s best to stay out of the water. Instead, perhaps scan the carcass from a safe distance and/or location and see if you can spot any sharks feasting on it. Maybe he’ll get his own drone and add it to the many videos we’re now seeing online of sharks…well, being sharks. Drones not only reveal the dark sides of a shark’s daily life, but also shed light on a new side of these predators. “The bottom line is that there is no question that drones have given people a different perspective. [on sharks] because they can see sharks around people and see that the sharks are not attacking,” Lowe concludes.