Fatal shore: Why so many shark attacks?
A spate of fatal shark attacks in WA has led to calls for drastic action. But what's behind the attacks?
THE ATTACK WAS so fast and powerful, Martin Kane, 61, barely knew what had happened.
One minute, he was on his surf ski, paddling off Perth’s Mullaloo Beach, WA, with three friends. “It was a great sunrise, shimmering water, a light breeze. I thought, ‘It doesn’t get any better than this – a truly glorious morning.’” Then there was “an almighty crash”, he says. “It was like a car crash, the ski exploded and there was a crunching sound.”
Martin found himself flailing in the water, and the 3m great white shark beside him was still ferociously attacking the ski. “I saw the dorsal fin...and I started to swim in what felt like concrete. The strange thing is that my mind was calm, with a total acceptance that I was going to die.”
Martin says he saw his friend Dale Gration nearby and screamed at him to get to safety. But Dale, 54, paddled over and managed to pull Martin onto his own ski. The whole party then made it safely back to the shore.
Although he escaped without physical injury, the attack, which happened in June, left a deep impression on Martin. “It had a very humbling effect on me. And it has greatly reinforced the important things in life.”
Lucky to escape with his life
In some ways, of course, he was lucky: he escaped with his life. In a 10-month period up to July 2012, five people were likely killed by great white sharks off the coast of WA – enough to have the region dubbed the ‘shark attack capital’ of the world.
“This is an unusual and tragic frequency of serious attacks,” says Rory McAuley, a great white shark specialist at the Department of Fisheries Western Australia.
It’s not surprising, then, that locals are desperately asking why. Have shark numbers rocketed? Should their protected status be questioned? Should there be a cull?
While there are still many unanswered questions about these sharks, work by Rory and others can at least help fill the information vacuum that has been driving speculation about why so many people have been killed in such a short space of time.
“You can walk into any pub in WA at the moment and ask anyone in the room why the shark attacks have occurred, and you’ll get a whole raft of different answers, which are rarely, if ever, substantiated by any evidence,” Rory says.
Uncommon number of attacks
Five fatal great white shark attacks in a year is certainly uncommon, but it isn’t unprecedented.
In NSW, there were six deaths in a 12-month period from 1934 to 1935, and in Queensland, there were five fatalities in 1929. But nowadays, the general trend in Australia, as well as the rest of the world, is towards more attacks.
There have been 207 unprovoked shark attacks in Australia over the last 20 years, and 124 of those occurred in the last 10 years, according to John West, curator of the Australian Shark Attack File at Taronga Zoo, Sydney.
In the past 12 months in WA alone, there was a total of eight recorded shark attacks, seven of them from great whites. This compares with an average for WA of 4.4 attacks each year over the past decade.
John attributes the increase in shark attacks in Australia, over the past 20 years in particular, to more people going into the sea.
According to estimates by Surf Life Saving Australia, the number of people visiting our beaches grew by a massive 20 per cent between the 2008–09 season and the 2009–10 season alone.
Rory says that around Perth the growth in coastal populations is clear, both in the statistics and to anyone familiar with the city. “If you look at Perth from the water at night, when you can see the lights of the suburbs, you see that it now reaches over a huge stretch of coastline, further than you can see in the north and the south.”
Too close for comfort. Martin Kane displays the damage sustained by his surf ski in June 2012. This is all that came between him and a great white shark that lunged at him off a Perth beach, as he took an early-morning paddle.
Changing number of people in the water
Access to beaches has also improved. A coastal road to Wedge Island, 180km north of Perth – where surfer Benjamin Linden lost his life to a great white in July – only opened in September 2010, and according to Rory’s sources there are now many more people surfing in the area.
Although scientists seem to have a good understanding of how the number of people in the water has changed in recent years, the data on great white populations are much sketchier. Ask Rory how many live in the waters off Australia, and he replies: “We wish we knew.”
Barry Bruce, a CSIRO scientist based in Port Stephens, NSW, is also cautious. It’s probably “more than thousands” he says. But there’s no real way of knowing, because it’s so difficult to count them, and so few are accidentally taken by fishermen.
Great whites have been protected in Australian waters since 1997. So, is it possible their numbers have boomed? If numbers had risen, you’d expect to see an increase in sharks reported as accidental catch, says Barry, and that hasn’t happened. Over the past five years, there has been a slight rise in the number of juveniles caught in the beach nets on the east coast, but this isn’t much above previous records, he says.
Biologically speaking, though, it’s impossible for our great white population to have soared, say Barry and Rory. Female great whites take about 16 years to get to breeding age, and then they only breed every 2–3 years, with just a few young surviving each time.
Shark biologists estimate that it will take two to three decades from the start of protection for the shark numbers to really rise.
Why so many attacks in WA?
Although more people in the ocean, rather than more sharks, may account for the trend towards more attacks, scientists can’t explain why there have been so many in WA in such a short time. Other clusters have been reported around the world, in the waters off Mexico, Hong Kong, New Zealand, Brazil and Iran. When asked about WA, Rory admits: “We are struggling to provide answers.”
Scientific data can rule out some suggestions at least. The Humane Society International claim sheep exports from Fremantle could be implicated, arguing that dead sheep thrown overboard might attract sharks. But this “isn’t substantiated by any credible data whatsoever”, says Rory.
Others have suggested that an increase in the number of seals living on the WA coast might be drawing more sharks closer to shore. It’s possible, says Rory, but white sharks are primarily fish-eaters, rather than seal-eaters. And the electronic tags that Barry, Rory and others have attached to sharks off Australia are showing that they don’t generally hang around seal colonies for long.
Some sharks spend months around colonies, some spend only days, and some return repeatedly while others don’t. If there are more seals in WA, it’s not clear how this would influence shark movements, says Rory.
The tagging program is key to understanding great white movements. Barry started attaching simple plastic identification tags to sharks in 1989, and more sophisticated ones, such as satellite tags, in 2000. Satellite tags transmit the shark’s location, and sometimes other data, to a satellite, which relays it to researchers (see “Great white shark nursery”).
Barry clearly remembers the first time he saw a live great white, while on his first tagging expedition in SA. “I was standing on the back of a boat around midnight in the middle of the Spencer Gulf... I saw this massive shark rise vertically out of the deep. It almost did a tail-stand under water then peeled off and swam around the boat... It was one of the most extraordinary experiences of my life.”
To date, Barry and his colleagues have satellite-tagged 40 great whites off Australia, and a further 100 have been fitted with acoustic tags, which transmit the date, time and a unique code for each shark to underwater receivers.
There are now hundreds of receivers throughout Australian coastal waters, set up under a national program to monitor the movements of many tagged animals, including sharks.
Shark detection network
In WA, Rory and his colleagues have now set up underwater arrays of acoustic receivers along the Perth metropolitan coast. If a tagged great white shark approaches a beach around Perth, an alert goes out to public safety authorities such as Surf Life Saving Australia.
Between 1 and 7 July 2012, the system picked up a tagged shark – the fourth detected in this way since the program got underway in 2009. Most of the signals came at night and in the early morning, so surf lifesavers were able to warn people as they started turning up at the beaches.
The satellite and acoustic tagging programs are designed to provide more general information about where sharks go, and since the start of tagging, “knowledge of the movement patterns of white sharks has skyrocketed”, says Barry. It’s now clear that great white sharks like to get around, and can spend long periods in the open ocean, regularly moving from temperate to tropical waters.
It also seems there are two separate great white populations in Australia: at least some members of the eastern population move up the coast as far north as Queensland in autumn and winter, returning south in spring; the southern/western population moves up as far as Exmouth, WA, during spring and appears to return south during the summer.
In California and Africa, scientists have recorded similar seasonal movements, which are probably made in search of the best spots to find food.
Research on shark movements also shows that, in some years, there are many more sharks than usual in certain regions and fewer in others. This doesn’t reflect a waxing or a waning in the overall population, says Barry – just shifts in their location. If, as it seems, great white sharks do sometimes gather more in coastal waters, “that is something that may well be a factor in the recent attacks in WA”, he says.
At the moment, no-one knows why this happens, though some kind of environmental triggers are likely to be involved, says Barry. He and his team are working to better understand the factors responsible, partly in the hope that they may be better able to predict shark movements – and perhaps sound the alarm if it looks likely that there’ll be more sharks than usual at a particular location and time.
Emotive and reactionary killing of sharks
But the tagging work has already shown that even when there are many great white sharks congregating in the water, people aren’t necessarily at a greater risk.
Barry and his team found that the nursery for the entire eastern population of great whites is a 50km-long stretch of coast around Port Stephens. In the 2008–09 summer season, one of the beaches there, Hawks Nest, was closed 44 times because sharks swam near the flags. Yet there has never been a recorded attack here – no-one knows why. Clearly there are still major gaps in our understanding. “It’s a journey and a jigsaw puzzle with many pieces still missing,” says Barry.
But he and others, including Rodney Fox, who was almost fatally injured in a great white attack off South Australia, back in 1963 (and who now heads the Fox Shark Research Foundation), hope the legacy of the tragic series of deaths in WA will be more research, rather than an end to the shark’s protected status.
Things aren’t looking good in this regard. In September 2012, the WA Government announced $6.85 million of funding for “shark mitigation”, including $2 million for tagging, but also $2 million to track and kill sharks deemed dangerously close to swimmers.
Fisheries Minister Norman Moore told reporters that the circumstances in which a shark could be culled had changed: “Previously, the orders were used in response to an attack, but now proactive action will be taken if a large white shark presents imminent threat to people.” Conservation groups, including The Wilderness Society, have been highly critical of what they called “pre-emptive cullings”.
Culling is simply an attempt to “justify the emotive and reactionary killing of sharks after attacks”, says Rodney. Kim Allen, who was with Martin Kane on the day of the June attack, wants to see more money put towards detecting sharks and issuing warnings. “If people are going to peacefully coexist with sharks, we need to use technology to let us feel safer,” he says.
But while we may not be able to manage shark behaviour, we can manage our own, argues Christopher Neff, who researches shark attacks at the University of Sydney. More education on the risks and how to minimise them – urging people not to surf at dawn or dusk, for example, when there’s a greater risk of an attack – might help reduce the number of deaths. He says: “I think we will all be safer if we treat the beach more like the bush.”
FIVE FATAL ATTACKS IN 10 MONTHS
14 July 2012 Ben Linden, 24, is killed while surfing near Wedge Island, 180km north of Perth. A witness who tried to help said the shark swam away with the body.
31 March 2012 Peter Kurmann, 33, is taken in south-western WA while diving in the Port Geographe Marina. His brother, who was diving with him, tried to fight off the shark with a knife.
22 October 2011 George Thomas Wainwright, 32, an American tourist, sustains horrific injuries and dies while scuba diving off Rottnest Island, near Fremantle.
10 October 2011 Bryn Martin, 64, disappears at Perth’s Cottesloe Beach and is presumed a shark-attack victim. Only his damaged Speedos were found.
4 September 2011 Kyle Burden, 21, is taken by a shark while bodyboarding with friends at Bunker Bay, near Dunsborough, about 300km south of Perth.
Source: Australian Geographic Nov - Dec 2012
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