Sharing the Sea with Sharks
In the South African coastal city where I grew up, shark incidents were fairly common out on the reef where the surfers congregated. As a boy, my father lost a friend to a shark at our local beach. He remembers how the kid who pulled his friend out the water was sent to school the next morning and expected to get on with things.
Now I live in Sydney, where I do the occasional open-water swim in a bid to confront my mild phobia of sharks. I still spend ninety-nine per cent of each swim thinking about them, which may explain my surprisingly fast race times. It doesn’t help knowing that the number of shark bites in Australia—and worldwide—has more than doubled since 1990. But that increase is not, in fact, cause for alarm. It simply reflects human population growth and higher numbers of oceangoers. Even in Australia, which has the highest number of fatal shark bites in the world, the risk of death from a shark bite is extremely low: a yearly average of 1.1 fatalities over the past twenty years. Meanwhile, we’ve been systematically killing off sharks, in spite of evidence that, as “apex predators,” they’re crucial to maintaining biodiversity. The populations of large predatory fish such as swordfish and sharks have been reduced by ninety per cent over the past century.
Recently, a series of fatal shark bites in Western Australian waters led to an unusual exemption for the state government from federal environmental laws protecting white sharks. In late 2013, the government was permitted to attempt a large-scale cull. The state’s Premier, Colin Barnett (dubbed “Captain Hook” by environmental activists), posed triumphantly for photographs beside a giant hook, designed to be used off state beaches. Any white, tiger, and bull sharks larger than three metres caught on one of seventy-two new drumlines—unmanned, baited hooks suspended from buoys—would be killed.
The public outcry was immediate. Thousands attended anti-drumline rallies across the country, and as far afield as London and Rome. More than three hundred marine scientists signed a public letter to the state government stating that there is “no evidence to suggest that the lethal drumline program … will improve ocean safety,” and that the government had ignored outcomes from a similar program in Hawaii that “showed no improved safety outcomes despite a lethal long-line program lasting 16 years that captured nearly 300 tiger sharks a year.” Sharon Burden, whose son died from a fatal white-shark bite, in 2011, was a leading member of the anti-cull campaign.
Sea Shepherd Australia took out a boat nicknamed Bruce to film private contractors and Fisheries Department staff as they checked the drumlines and killed target species. The footage is distressing to watch. The hook “usually went into the shark’s mouth and outside their head at the side of the mouth, then over and back into their head again,” Shayne Thomson, an ex-Fisheries Department employee turned conservationist and filmmaker, explained. “These sharks had horrific injuries. Even the ones that were released would not have survived. It was not humane.” He and other concerned observers saw many of the larger tiger sharks being shot several times, and shark species being wrongly identified or sized.
During the three-month drumline trial, a hundred and seventy-two sharks were caught (a hundred and sixty-three were tiger sharks, which have not been responsible for a fatal shark bite in the region since 1925), and sixty-seven were shot or died on the line. Of the marine animals caught on the drumlines, seventy-one per cent were classified “non-target,” such as stingrays or harmless shark species, or undersized sharks. In October, 2014, the government abandoned its drumline policy after suffering a major political embarrassment: the state’s Environmental Protection Authority recommended that the program be discontinued due to uncertainty about its “impact on the environment,” and on white-shark populations in particular. There is still, however, a controversial catch-and-kill order in place for any sharks deemed to be a “serious threat.”
“The drumline policy was designed to provide public catharsis through retribution, not public safety,” Christopher Neff, a public-policy shark expert who teaches at the University of Sydney, said. Neff grew up in New England and was a “shark kid” from an early age—he kept a huge cut-out of a white shark in his bedroom, and on a trip to Martha’s Vineyard was thrilled to ride in a cab that had been used in the movie “Jaws.” His research has shown that governments tend to respond to shark incidents by addressing public perception of the risk through “a bunch of symbolic policy responses that do nothing to address the underlying level of risk but are helpful politically.” In the past, communities have sometimes lashed out at elected representatives in the aftermath of a shark bite. After a string of now infamous shark bites in New Jersey in 1916 (which inspired the book and then movie versions of “Jaws“), for example, voters in nearby districts tended to vote against the party in power.
However, Neff believes that governments have been misreading the contemporary public’s mood and attitudes toward sharks for a while. Several surveys have shown that the vast majority of Australians no longer supports radical, lethal action after a shark bite, even a fatal one, and many don’t want shark-control programs at all. Neff said that this is true for many beachside communities around the world that share their local beaches with sharks.
Neff’s research has also highlighted the need for more accurate language to describe shark incidents. For example, he found that, in the past thirty years, thirty-eight per cent of shark “attacks” in New South Wales, where Sydney is located, resulted in no injury to a human. In 2013, Neff co-wrote an influential paper recommending a new set of categories for describing shark incidents: sightings, encounters, bites, and fatal bites. The American Elasmobranch Society (the world’s largest shark and ray science society) recently petitioned the Associated Press and Reuters to include these terms in their style guides, and I have tried to use their categories—though I was disappointed by how often I was tempted to use the more chillingly evocative term “shark attack.”
Public opposition to established shark-culling programs on the east coast of Australia is also growing, in part because of campaigns run by environmental groups like Sea Shepherd, No Shark Cull, and Support Our Sharks. Queensland, for example, has a “mixed-use” program of more than three hundred and fifty drumlines and twenty-nine shark nets, and New South Wales’s Shark Meshing Program uses fifty-one shark nets.
In 1937, when the first shark nets were installed off Sydney beaches, on Australia’s east coast, sea-bathing was still a relatively new pastime—prior to 1903, daylight ocean bathing had been banned as improper. At the time the nets were introduced, the state’s beaches were experiencing, on average, one fatal shark bite every year. The government felt that it needed to be seen as proactive, and nets were one of the least hawkish measures proposed; suggestions made during a 1935 public-submissions process included mounting machine guns on headlands and setting explosives. From the outset, the purpose of the nets was to catch and kill sharks.
Almost eighty years later, the nets are still installed off the New South Wales coast. They go in at the start of September, the beginning of the warm-weather season, and are removed at the end of April. At each of the fifty-one participating beaches, nets are installed for fourteen days of the month. They do not act as a total barrier: they are generally only a hundred and fifty metres long and six metres wide, and are set beneath the surface in ten to twelve metres of water, five hundred metres out from the shore. They’re anchored to the sea floor, but there is significant space above and below them. (A study of a similar shark-net program in South Africa found that thirty-five per cent of the catch was “on the shoreward side of the nets”—in other words, sharks are often caught on their way out to sea.)
Allyson Jennings, the New South Wales coordinator of Sea Shepherd’s anti-cull campaign, said that, since 1950, when data began to be officially recorded, the Shark Meshing Program has entangled more than sixteen thousand marine animals. In the 2013-2014 season alone, a hundred and eight animals were officially reported tangled in the nets, of which seventy-six per cent were non-target or threatened species. These include grey nurse sharks, which look fierce but are rarely aggressive toward humans, and are considered a critically endangered species; turtles; and rays. Two humpback whales have become entangled in the nets in the past two years. Mortality rates for entangled animals are high. The nets used are “gill” nets, and, as their name suggests, they have fine mesh designed to catch in the gills of large creatures and cause serious damage as the animal thrashes until it drowns. Contractors are required to check the nets every seventy-two hours, weather permitting, and to free any marine creatures still alive if “practical and safe to do so”—but Jennings said that, in reality, “nets are sometimes only checked once a week.”
The most controversial aspect of shark-net programs is whether it has been scientifically proven that shark nets reduce shark bites. Some researchers who have worked for government shark-meshing programs over a long period wholeheartedly believe that they do. Since the start of the KwaZulu-Natal Sharks Board netting program—which uses much larger nets, for a longer period, than the New South Wales program—there have been “only two attacks, both non-fatal … at protected beaches … over the past three decades.” And the New South Wales government reports that since “the NSW shark meshing program was put in place in Sydney in 1937, there has only been one fatal attack on a meshed beach.”
However, the New South Wales Fisheries Scientific Committee—which is required by law to review the performance of all parties involved in the Shark Meshing Program— has for years reported its concerns about the scientific and research aspects of the program, in particular the claim that the program has been effective at providing a safer environment for swimmers. The committee believes that “this statement is unsubstantiated because it is not based on a scientific comparison between meshed and unmeshed beaches of shark numbers, interactions or attacks,” and said that it has repeatedly asked for the claim to be removed from official program reports, to no avail. But, while Cliff believes in theory that this kind of comparison would be useful, he said that, in practice, it would be very difficult to carry out. “Catches in shark nets are often the only indication we have of shark-population numbers,” he said.
Other shark scientists, however, support the committee’s criticisms. Ryan Kempster, a shark biologist at the University of Western Australia and the founder of the Support Our Sharks conservation society, told me, “It’s extremely hard to prove that such programs are successful in reducing human fatalities. This is because decreases in shark-bite incidents may simply reflect broader declines in shark populations, driving down encounter rates.” Hueter agrees. “Removing X number of sharks from a specific area does not insure that nobody is ever bitten by a shark there again,” he said.
“Shark bites fall into a very particular statistical category as rare and random events,” Neff said. “Claiming that a decline in non-fatal shark bites is due only to the presence of nets is a case of correlation without causation.” He has highlighted that sixty-three per cent of all New South Wales shark “attacks” between 1937 and 2008 occurred at meshed ocean beaches, which suggests that the nets don’t stop sharks from biting but, rather, that the bites often are no longer fatal, thanks to better on-scene medical treatment and the availability of antibiotics. He also suggests that improved water quality may have contributed to the decrease in fatal shark bites at meshed beaches over time. (Until 1970, Sydney’s abattoirs discharged offal through the sewage outfall.)
Either way, nets and drumlines are increasingly painted as crude, antiquated shark-culling tools. Shark scientists and entrepreneurs are now starting to direct their energies toward finding a technological solution that could keep both humans and sharks safe. The KwaZulu-Natal Sharks Board, in response to growing opposition to shark nets, aims to come up with a “non-lethal alternative.” It has been researching electronic shark-deterrent technologies since the nineteen-nineties, based on findings that a shark’s electroreception system—clusters of nerve fibres in gel-filled canals, visible as dark pores on a shark’s head—may be sensitive to changes in electrical fields. The board recently began testing a hundred-metre cable that emits a low-frequency pulsed electronic signal designed to repel sharks.
Nathan Hart, a marine neuroscientist at the University of Western Australia’s School of Animal Biology and Oceans Institute, has been studying shark vision for years. His research has shown that many shark species are most likely colorblind. Some of Hart’s findings have found a commercial application in two shark-repellent wetsuit designs by a Western Australian biotech company, SAMS. One is a camouflage pattern for snorkelers and divers, designed not to scare the shark away but to introduce visual ambiguity: “You can’t see me, or you’re not quite sure what I am, and you may leave me alone,” Hart explained. The other is for surfers: a black-and-white stripe design mimicking the patterns of a pilot fish or banded sea snake, which sharks are known to avoid. “This is the ‘Yes, I’m here, but you don’t want to eat me’ approach,” he said
There are many other related ideas still in their infancy: a playback of killer-whale screams underwater, air-bubble curtains, strobe lighting, artificial kelp forests. SAMS is also developing a sonar shark-detection device, called a Clever Buoy, with the Australian telecommunications giant Optus and Google as partners. There’s the Eco Shark Barrier, a strong but flexible modular enclosure, which is being tested in the calm waters of a Western Australian beach. People have been travelling from surrounding areas specifically to swim there since it was installed; many users say that it gives them complete peace of mind, especially when swimming at dawn or dusk. Researchers at the Center for Shark Research at Florida’s Mote Marine Laboratory are investigating a range of magnetic, chemical, and electronic shark electroreception-system stimulants. And the New South Wales government recently pledged a hundred thousand dollars to test new shark-mitigation technologies at Sydney’s beaches next summer, a sign that it’s aware that the shark-net approach might be outdated.
Most of the shark scientists I spoke to believe public education is still the best method of protecting oceangoers and marine animals, especially while a technological solution is still years off. Many cite Cape Town’s Shark Spotters program as a gold standard because of its emphasis on observation and education: community members on beachside cliffs use flags and alerts to keep the public informed of shark sightings. “As an effective approach, education is number one,” Hueter, the Florida-based shark expert, said. “Most people here have embraced the idea that this is the sharks’ home, their natural habitat, we’re going into their space. … People respond to a shark-bite incident differently now. It’s a tragedy, yes, but it’s accepted as something out of our control, like being struck by lightning.”
“We’re not just afraid of predators. We’re transfixed by them, prone to weave stories and fables and chatter endlessly about them, because fascination creates preparedness, and preparedness, survival. In a deeply tribal sense, we love our monsters.” These words from E. O. Wilson, the Harvard socio-biologist, could be quoted by people on both sides of the shark-cull debate. For some, the takeaway is that we need to be prepared in order to survive; for others, that we need to find better ways of expressing our love for our monsters. His words made me think of an encounter that my husband and I had with a small Galapagos shark while snorkelling on Lord Howe Island. When I saw the shark’s shape approaching underwater, I was filled with unexpected joy—we had been told that the juveniles were harmless. I spluttered to the surface to tell my husband, but he had mistaken my rapid movements for fear, and had done a slow-motion underwater clap to scare it away. Afterward, we felt ridiculous, and also bereft, aware that we had wasted a precious opportunity to gaze at this magnificent creature. We kept returning to the same spot to snorkel, but never saw another shark again.
Source: The New Yorker