Drones for shark observation on beaches are more effective than nets
To protect bathers on Australian beaches, drones were used to locate sharks. The study is considered a success, and the program will be expanded.
A shark from the perspective of a drone.
(Image: Jonathan Mitchell u. a.)
A four-year study by the Australian state of Queensland concludes that monitoring sharks with drones near beaches is significantly more effective than using nets and drum lines. Around twice as many sharks could be detected and observed without harming the marine animals.
During the four-year study period, the drones, mainly of the DJI Mavic type, were only in operation in the morning hours until noon. They were controlled by specially trained lifeguards at ten beaches in Queensland, northeastern Australia. In total, 676 shark sightings were detected during nearly 18,000 flights, covering a total distance of 7181 km. Only about five percent of the flights had to be canceled due to weather problems or technical difficulties.
Drones More Effective Than Nets and Drum Lines—and Non-Lethal
The existing nets and drum lines of the Shark Control Program (SCP) registered only 387 sharks during the same period: 284 in nets, 103 on drum lines. Although permanently installed, they registered only about half the number of sharks compared to the drones. However, nets and drum lines have another disadvantage: they can be lethal to sharks. Sharks, as well as other marine life, can get caught in them and die agonizing deaths. In contrast, the drones do not disturb marine animals and have no further impact on the environment.
A total of 4959 individual sharks were sighted with the drones. Among them were 190 with a length of more than two meters. These were mostly tiger sharks or bull sharks. A great white shark was also among them, according to the study (PDF).
The identification of the sharks was made possible using high-resolution cameras. By analyzing the videos, the species could be identified. The lifeguards determined the size in real-time via the video stream and, if necessary, cleared the beaches immediately to protect bathers. 39 beach clearings were carried out.
Expansion of Drone Deployment
Lifeguards consider the drones an effective tool for early detection of sharks—at least on beaches with clear water. The animals' behavior can be analyzed in real-time, and measures can be taken judiciously without overreacting.
Queensland's Shark Management Plan for 2025 to 2029 envisages expanding drone usage. Instead of ten, 20 beaches will now be monitored with them. Furthermore, the use of autonomous drones and AI-supported shark detection is recommended. Flights will also be expanded.
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However, nets and drum lines will continue to be used, even though they pose a danger to marine life. There are already initial considerations on how a modern monitoring system can be established that make the lethal nets and drum lines obsolete.
(olb)
