Surfers have long shared the ocean with the looming fear of shark attacks, often wondering how to safely enjoy their time on the waves without drawing the attention of these majestic predators. A recent breakthrough by Australian researchers might just change the game, providing surfers new hope with innovative use of technology to ward off potential shark threats.
The study, spearheaded by Dr. Laura Ryan and her team from Macquarie University, has found compelling evidence showing how LED lights, when applied strategically, could deter great white sharks from mistaking surfers and their boards for their usual prey, such as seals. Conducted across six years of experiments spanning different configurations, these insights could pave the way for practical applications.
The researchers took to the waters off Mossel Bay, South Africa, which is renowned as a favored hunting ground for great white sharks. Rigged with bright, illuminated decoys shaped like seals, the team towed these devices behind boats, observing how different lighting patterns influenced the sharks' behavior. "There was quite the spate of shark bites during my time surfing, which got me thinking significantly about shark eyesight," said Dr. Ryan. Motivated by the need to protect those who share the waves, her quest began.
The methodology behind the study was straightforward yet ingenious. The team deployed seal-like decoys with various LED lighting configurations: some dim, some bright, and some featuring horizontal and vertical stripes. They needed to determine if the lighting could distort the silhouette of the decoys against the shimmering ocean surface, thereby influencing the sharks' perception.
The results turned heads. Published in the journal Current Biology, the findings indicated brighter lights, especially those aligned horizontally, were significantly less attractive to great whites compared to unlit decoys. Sharks showed almost zero interest when the decoys were brightly lit. "The brightness had to be equal to or more than the surrounding light to effectively disrupt the silhouette," Dr. Ryan explained. Consequently, the study shines light on how making objects brighter can trick predators who rely heavily on visual cues.
Interestingly, the team concluded horizontal stripes on LED lights proved to be particularly effective. These stripes made shapes appear wider than long, breaking up the typical seal-like outline and getting through to the minds of hungry sharks. Dr. Ryan observed, "Every time we used the striped design, there were no shark attacks. A success worth noting!" On the other hand, vertical lights did not perform as well, possibly giving the sharks just enough information to infer the silhouette.
For the surfers, this means iconic bright colors and patterns might not just be eye-catching aesthetics, but could also provide much-needed safety. According to Professor Nathan Hart, who participated in the research, this approach is akin to creating an "invisibility cloak" for surfers. "What we’re doing here is splitting the silhouette, effectively making it harder for sharks to pinpoint actual prey," he detailed. With their focus now shifting from decoys to surfboards, the research team is developing prototypes outfitting actual surfboards with these lighting technologies.
Notably, with multiple shark attack incidents worldwide and statistics noting great whites as being responsible for most fatal bites, this discovery couldn't come at a more opportune time. Reports state there were 69 unprovoked shark bites recorded globally last year, with Australia, the U.S., and South Africa being the hot spots.
The study also touches upon the importance of visual perception across different shark species. Dr. Ryan mentions the need for follow-up inquiries to understand how these lighting configurations might affect the behavior of notorious human attackers like bull sharks and tiger sharks, whose hunting tactics could differ from those of great whites. "We need to establish if the effective strategies for great whites can also be applied to other species," she said.
While great white sharks don't typically view humans as prey, the confusion can lead to unfortunate and harmful encounters. Therefore, these discoveries offer not only hope for surfers and swimmers but also provide the potential for more humane shark deterrent methods instead of the often deadly alternatives like nets and drum lines.
Dr. Ryan emphasizes the practicality of embedding these LED lights directly onto surfboards themselves, mixing functionality with safety: "I want this to be usable. We believe this can let surfers feel more secure out there, knowing they have the means to coexist peacefully with one of the ocean's most powerful creatures." With so much at stake, it’s clear the tides of surfing safety may soon shift, thanks to the bright—and rather stylish—solutions offered by the science of light.
