PBS explores 'Why Sharks Attack'
The team behind the new 'Nova' documentary seeks to understand more about these predators and the cutting-edge ways we can prevent negative human-shark encounters.
Tue, May 06, 2014 at 03:47 PM
From Cape Cod to the coast of Australia, shark attacks have become more frequent, scaring the pants off beachgoers. As the new “Nova” special “Why Sharks Attack,” premiering on May 7 on PBS, recounts, scientists are researching the phenomenon with a two-pronged approach: they’re studying migration patterns and prevention solutions, analyzing shark brains and senses to find methods of deterring the predators, including electrical fields, flashing lights, and wetsuit patterns that camouflage the wearer in various ways.
Senior “Nova” producer Julia Cort, writer/director Adam Geiger, and Colette Beaudry, executive producer for SeaLight Pictures, talked to MNN about their documentary, offering insights about the rise in shark-human encounters and the latest scientific developments in preventing them.
MNN: First, how did the program come about?
Colette Beaudry: It was September of 2012 and the radio was on. People across Australia were calling in and everyone was heated and emotional. It was about sharks. As an environmental filmmaker who’s made other shark shows and numerous marine-related television series, I was drawn to the passion I was hearing from such an array of different community voices: surfers, scientists, beach-goers, fishermen, conservationists, parents, local politicians and the like.
The controversy was twofold: First, there was a change in the nature of Western Australia’s human-shark incidents — from attacks, where the person usually survived, to fatalities — five fatalities, in fact, within a 10-month period ending in July 2012. All of them suspected to be from great white shark attack. Equally newsworthy was the Western Australian government’s suggested reaction, which was to cull large shark species near Western Australia beaches. Many factual shark shows focus on the drama of the attack and on the survivors. I’d never heard a survivor say that they were for killing sharks. Survivors tend to be people who love the water, are glad to still be alive, and don’t begrudge sharks their right to exist in a habitat that's their home first and foremost, not ours. Hearing that sharks — important apex predators in our ecosystem — were going to be killed upset and concerned me. Great whites, for example, are a threatened species. So little is known about these creatures, yet the University of Western Australia’s Professor Shaun Collin was now leading a whole team deep into new shark science.
SeaLight’s director, producer and writer, Adam Geiger, is a dual Australian-American citizen, originally from Martha’s Vineyard, near Boston, Massachusetts. With a marine science background himself, his first port of call was esteemed colleague Dr. Greg Skomal, lead shark biologist for the Massachusetts Division of Marine Fisheries. While Skomal had been researching sharks for most of his career, he never expected to be studying great whites, especially not in his backyard of Cape Cod. And yet, in the last five years, he’d gone from never tagging a great white shark to tagging 34 of them. And there’d been a great white run-in with a human who survived. “Why Sharks Attack” follows these two engaging scientists, in Australia and in the U.S., in a way that no show had ever put together before.
There are a lot of shark-oriented programs on TV — i.e., Discovery’s Shark Week. Why the ongoing fascination? And what makes this one different?
Julia Cort: People are naturally both fascinated and fearful of sharks, but the key for “Nova” is the science behind the dramatic headlines. “Why Sharks Attack” explores new scientific research into great white sharks, especially about how they sense and target prey. And this isn’t just an Australian story. At the same time that the increase in fatalities was being reported over there, here in America off the beaches of Cape Cod, sightings of great whites have been increasing rapidly. Why is that happening? Are attacks inevitable? Is there anything we can do to avoid them? We wanted to follow the scientists who are working hard to track and understand these apex predators, animals that are crucial to the ocean’s ecosystem. The more we can know about them, the better chance we’ll have of avoiding fatal interactions with people in the future, and ultimately protect both people and sharks.
Beaudry: This show is different because it’s dedicated to revealing some very new science. The facts have been vetted multiple times across two countries and the scientific community at large. It’s also different because it intimately accesses top great white research being conducted in two different places — one halfway around the world from the other. Finally, this show is different because a spike in fatal attacks is different from a spike in attacks. A succession of shark-related fatalities is usually the realm of fiction.
So why are shark attacks become more prevalent?
Beaudry: Scientists are understandably unwilling to point a finger at any one cause, when there are likely many reasons. Even stating that shark attacks are more prevalent is too broad a statement. What’s increased is known human fatalities in the recent, stand-alone case of Western Australia. One correlation between the U.S. and Australia is that they each passed marine mammal protection acts. It could be that a possible food source for great whites is more abundant than in the past, or that there are simply more people in the water.
The documentary depicts testing of various shark deterrents. What are the theories behind these and which do you think are most promising and practical?
Adam Geiger: In “Why Sharks Attack,” the scientists focus on the sensory systems of sharks to design deterrents, based on years of research into shark biology. Sharks possess senses similar to our own: sight, hearing, smell, taste, and touch. But they also have extraordinary senses beyond our own: a lateral line system that detects vibration and movement in the water — the wake of a passing fish or vibrations of a fish in trouble — and an electro-sense sensitive to one-billionth of a volt: the twitch of a muscle or beat of a heart.
Shaun Collin and his team at the University of Western Australia target all shark senses, but in the film, we focus on visual and electrical senses. First, the visual sense: a flashing-light deterrent emits a very bright light flashing at an interval determined by how quickly a shark’s eye can register light. The idea is that the flashing light will be uncomfortable for the shark to look at. Series of flashes are separated by several seconds, with the intent of preventing the shark from becoming habituated to the light. The team also tests electrical deterrents that are currently on the market, devices that emit a strong electrical field that’s uncomfortable but not harmful for a shark, and can be worn around the ankle by a diver, surfer or swimmer.
Another concept Collin has developed is the use of different-patterned wetsuits worn by divers and surfers; one designed as camouflage, the other as warning sign. Collin has pioneered the study of shark eyes, learning that most sharks are color blind, seeing the world more or less in black and white. They key on contrast and movement. The colors of the camouflage suit were designed specifically considering what part of the spectrum sharks can see at different water depths. The pattern is based on what Collin has learned about the resolving power of the shark’s eye. The idea is that, especially for visual hunters like great whites, the camouflage wetsuit will dramatically reduce a diver’s silhouette, and blend into the water background, making them of little interest to an animal that focuses in on the outline of fish and seals. The second wetsuit design is very different. It’s a black-and-white banded pattern modeled on the warning coloration of the banded sea snake. Sea snakes are highly venomous, and toxic for most sharks to eat, so they’re avoided. Collin scaled the pattern to be easily viewed by a shark from about 10 meters away.
In the tests they’ve conducted, Collin’s team has seen a high degree of effectiveness of the flashing-light deterrent. At this point, the light is powered by a large battery housed at the surface of the water. Collin believes they can make the battery smaller and wearable by a diver. The light might be tethered to a diver’s ankle, much as the electrical deterrents are. The electrical deterrents seem at times effective, but at other times, Collin’s team has witnessed sharks becoming aggressive to the deterrent, actually biting it. The wetsuit designs seem to work; however a lot more rigorous testing is needed to really assess their effectiveness. Collin’s mission to find effective deterrents is no easy task. Different species of shark rely on different senses, and each individual animal may react differently. So far, though, Collin and his team have made huge strides in understanding how sharks sense and process the world around them, and each of the deterrents they are testing hold promise because of the rigorous degree of research applied. In another six months, Collin will be even further along in developing and testing deterrents; it would be a good time to check in to see which have performed best.
Why was it important to include a message about shark conservation?
Beaudry: I believe it was important for everyone involved in this film to inform audiences and deepen viewers’ appreciation for such formidable, yet extremely vulnerable, species as sharks. The most impactful way to tell animal stories is often in relation to how they affect humans. Sharks may, on rare occasion, harm us, but by killing them, we are harming ourselves and our oceans on a far larger scale. This message is not new, yet the need to protect sharks, and all species, remains urgent. Wendy Benchley, a tireless shark supporter who appears in this film, is particularly alarmed by the shark-fin soup demand in Asia, and the decline in many shark populations around the world. In Western Australia, extensive financial support of new research into preventing future shark attacks on humans is unprecedented, and welcome in the hopes that shark culling, and shark attacks, could both become a thing of the past.
What do you want viewers to take away?
Beaudry: I believe that anyone who makes a factual shark documentary must ultimately be on the side of the sharks. It’s impossible to get close to a subject without at least understanding and respecting it immensely. Sharks are majestic, and apex predators are key to every healthy ecosystem on the planet. The more that science can help us avoid being attacked by them, the less vengeance might be unleashed on them and their natural predatory behaviors.
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