Perils of Oz
If the red-back spiders under loo seats dont get you, the blue-ringed octopus will... People delight in spreading shock-horror stories about Aussie wildlife, and often it works. Marie Davies has been instructing prospective divers downunder and finds that many are terrified of being eaten by sharks - or worse. She sets out to put their fears in perspective

VAST, DIVERSE, EXOTIC and home to the largest tropical reef system in the world, Australia is a divers dream. Each year, lured by cheap airfares and strong currency, Brits flock downunder to don their scuba gear and explore its underwater technicolour paradise.
     Scuba diving in Australia is still a growing sport, if PADI qualification figures are any guide. And each year more and more reports surface of the potential dangers downunder, with shock-horror headlines grabbing the imaginations of the public.
     Its true - by dipping your fins into the Pacific Ocean, you could conceivably become a shark snack, or fall victim to a potentially lethal bite or sting. But are these fears justified
     Sharks have killed more people in Australian waters than anywhere else in the world, averaging about one fatal attack per year - until last year, when no fewer than five people died. Three of these attacks were by great whites. Previously, there had been only nine Australian fatalities in 10 years, although the deaths of three other people are also believed to have resulted from shark attacks.
     Worldwide attacks peaked at 79 last year, the highest in 40 years, according to the University of Floridas International Shark Attack File. But it is attacks on people at the surface, surfers and swimmers, which are the most common, accounting for almost four-fifths of all attacks.
     Until 1994, not a single scuba diver had been killed by a shark downunder. So can divers breathe easy
     Not quite. Australia now has the second highest percentage of attacks on divers in the world after the USA. In 1999, 11 per cent of Australian shark attacks were on divers and snorkellers, and this rose to 18.4 per cent in 2000.
     There are about 400 different species of shark but only a handful have ever been known to attack humans, and most of these attacks were not fatal.
     Over the past 200 years it is the grey nurse shark (known elsewhere as the sand tiger or raggedtooth) that has accounted for 43 per cent of attacks worldwide. But the great white shark (Carcharodon carcharia) is the stuff of Hollywood legends, and is regarded as the most deadly shark found off Australias coastline.

Last year, two surfers were killed off the coast of South Australia in attacks on two consecutive days, and two months later, a great white fatally bit off a swimmers leg in waist-deep water in Perth, Western Australia. Why are such attacks on the increase Chris McDonald, Shark Supervisor at Sydney Aquarium, says that one of the main reasons is the huge reduction in fish populations.
     The amount of food available in the ocean is decreasing and sharks are now travelling further afield to feed. They are attracted to movement and sound in the water, but many experts believe that mistaken identity is the major reason for attacks on humans, especially in poor visibility such as in breaking surf. In such conditions swimmers, surfers or non-submerged divers can resemble seals at the surface, and seals are the great whites favourite snack.

Global warming might also be a factor, says McDonald. Changing temperatures in the water means changing patterns in shark migration. This means sharks are coming closer to shore and, with more holiday-makers taking up water pursuits such as diving and surfing, the odds of being attacked, whether mistakenly or not, increase accordingly.
     Shark fans cite cage-diving as another reason for the incidence of attacks. By encouraging human interaction with sharks, they argue, we are associating ourselves with food.
     McDonald, however, does not believe that instigating a jaw-to-jaw encounter is one of the factors. Contrary to what people believe, the great white isnt much of a threat to humans, he says. The most common shark attacks are from tigers, dusky whalers and bull sharks.
     Bull shark attacks are especially common, he says, as the species is attracted to people swimming in very shallow waters.
     British backpacker Rob Collins was training as a PADI Dive Master in Airlee Beach, Queensland, when he had his first encounter with a potentially lethal shark. During a morning dive, a 3m tiger shark circled the dive group while they were hanging on the descent line.
     The dive was awesome but just as we were coming up I saw a large shadow out of the corner of my eye, he says. Wed been diving with blacktips and whitetips so I knew it was a shark. But this one scared me because it was three times as big.
     Then the sunlight just glinted off its body for a second and I realised it was a tiger. Id heard loads of stories about them attacking divers and I felt a bit like bait just hanging there. Then I lost sight of it, which was even more scary.
     Fortunately, the shark did not reappear and all the divers surfaced safely. Robs buddy, Lisa McQuillin, was the only other diver to see the tiger. I was really scared, she said, and when I told the other divers they were a bit shocked. Some of them didnt want to go back in the water, even though we were moving to a different site.
     However, like many divers, Lisa is quite nonchalant about the unexpected visitors. You couldnt really blame the shark if it did attack. I mean, we were in its backyard, after all.
     The dive began in the twilight hours of early morning, when sharks are at their most active, and most hungry. Recently a mans head and limbs were found inside a tiger shark, caught off Lord Howe Island in New South Wales, which just goes to show how unpredictable these guys can be. But the fact is, only rarely do they attack divers.
     If you want to dive in a statistically safe spot, choose Sydney. There are frequent sightings of sharks around the bay, but there hasnt been a fatal attack in the harbour since 1963. If you want the facts, top of the league for attacks is Queensland (37.5 per cent), with New South Wales and Western Australia coming in joint second with less than half this number. Surprisingly, there has been only one recorded attack on a diver in Victoria, and attacks are rare in Northern Australia too.

However, the north has other dangers for divers - if a crocodile doesnt get you, you could be prey to an extremely toxic tentacle. Australia is host to the most venomous marine creatures in the world, but the sting from a box jellyfish, or sea wasp, is definitely one to avoid.
     Box jellyfish have between 10 and 60 stinging tentacles, each armed with up to 5000 stinging cells or nematocysts. Chemicals on human skin activate the cells and contact could be fatal for an adult. Last year there were about 70 reported deaths in Northern Australia between November and April.
     These creatures are more likely than sharks to come into accidental contact with humans, which earns them the Most Dangerous title. Ricky Chan, a marine biologist from the University of New South Wales, says this is due mainly to their transparency, which makes them difficult to see in the water.
     They are not aggressive creatures, but when swimmers fail to see them and bump into the tentacles, the jellyfish release their toxic cells in defence. They probably cant penetrate through wetsuits, but in tropical waters divers normally wear a shorty, so there will inevitably be exposed bits, says Chan. Interestingly, turtles are not affected by their sting and even eat these invisible creatures!
     But because of the risk box jellyfish pose to humans, for six months of the year (October - April), as they drift close to the shore, the beaches of Northern Australia are closed.
     If you should get stung by a box jellyfish, you wont get off lightly. Victims have reported excruciating pain which can last for weeks. Experts recommend that you dont try to remove the tentacles while they are still active, as it worsens the injury and leaves scars. On all beaches in northern Australia youll find tubs of vinegar, which deactivates the tentacles.
     Ice-packs can ease the pain; basic first aid, artificial ventilation and CPR may also be needed.

Another non-aggressive creature is the tiny blue-ringed octopus, which prefers to hide away from prying dive masks in rock pools and shallow coral. The chances of a diver being bitten by one are small, and the reason it is considered one of the most deadly organisms in the world, says Ricky Chan, is because it attracts attention.
     When the blue-ringed octopus feels threatened, rings on its body change from dark brown to bright neon blue and it looks very pretty, he says. But this is just its way of advertising its toxicity and is a warning for you to stay away.
     When the octopus is not angry it displays a yellowy-brownish colour, enabling it to blend with the sand and rock. This makes it hard to see, but any divers who accidentally put a hand on one could be in for a nasty surprise.
     If you mistakenly touch a blue-ringed octopus, it will inject you with lethal enzymes that cause paralysis. The bite is painless but the toxin travels through the saliva into your bloodstream. Death can occur within 30 minutes, usually from respiratory failure bought on by the venom, rather than drowning due to the paralysis. There is no anti-venom available in Australia, so if you do get bitten, artificial ventilation is recommended until the effects of the venom disappear.
     There have been very few diver fatalities from either box jellyfish or blue-ringed octopus, mainly because both creatures favour shallow near-shore waters and divers tend to dive a little deeper and usually off boats. They also tend to be more aware of the potential dangers of marine creatures than swimmers or surfers.

In the depths of Australian waters another venomous creature lurks - the sea snake. There are approximately 50 species worldwide, and about 32 live in northern Australian waters. They like warm tropical water, though sightings have been reported as far south as Sydney.
     Even though nine of the 10 deadliest snakes in the world live downunder, there are no documented fatalities from sea snakes. They are usually pretty inoffensive and over the past 10 years, only three incidences of bites have been recorded.
     However, these slippery critters are predators and, even though they have small mouths, they can bite. Their venom is two to ten times as toxic as a cobras but, luckily for divers, they usually transfer only a small amount to their victims. Only a quarter of those bitten show signs of poisoning.
     Distinct teeth marks are left, but there isnt much pain or swelling. The bad news is that envenomation can paralyse the nervous system, making breathing difficult. Eventually, the victim can suffocate to death. Kidney damage and heart failure may also occur, due to muscle destruction.
     Anti-venom is available, though this has some nasty side effects, including rashes, fever and joint aches and pains. To treat a bite, remove the surface venom, apply a pressure bandage, remain calm and go immediately to a hospital.
     Finally, sea snakes are incredibly curious. Fascinated with my hoses and fins, I fell victim to their inquisitiveness only recently whilst diving on Ningaloo Reef in Western Australia.
     Its amazing how fast you can fin when a yellow-belly sea snake is chasing your tail!

The best way to eliminate the chance of being picked on by a shark or bitten or stung by a venomous marine creature is to stay clear of the water, but as that advice is worse than useless to divers, just avoid touching anything and try to look as little like a seal as possible.
     Attracting considerable attention in Australia these days is the shark repellent rod or SharkPOD (Protective Oceanic Device). It emits a type of electrowave thats supposed to annoy sharks and can keep them at bay for up to 10m. Its effectiveness varies according to species, though tests show that its pretty convincing around great whites.
     As the power has to be turned low enough to prevent the diver getting shocks, the repellent is less effective than it might be. But there is now talk of the technology being miniaturised and put into BCs and lifejackets.
     The Australians seem to believe in it, and used such devices during the triathlon event at the Sydney 2000 Olympic Games. It wouldnt have done for any of the swimmers to have been chomped in front of millions of people worldwide!
     If you dont have the luxury of a SharkPOD and find yourself in the water with the most feared of sharks, you might not know it anyway. Great whites creep up on their prey, usually attacking from underneath. If you do see one, Ricky Chan suggests you drop to the bottom if possible and wait for it to disappear.
     Make sure you know where the shark is and dont forget to look underneath you as well, he says. Studies have shown that aggressive behaviour also deters them. They are very defensive creatures and they dont want to hurt themselves if they can help it.
     Watch out for aggressive movements such as back-arching, or throwing back the head - this manoeuvre places the mouth in a better position for biting. And in the unlikely event that it does attack, Rickys advice is to jab the shark in the eyes or gills. Best of luck with that!
     As to the overall likelihood of being attacked by a shark when diving downunder, youre more likely to be struck by lightning than be eaten by a big fish with big teeth. My advice is, get yourself a lottery ticket as soon as you land, get ready, get wet, and relax. As the Aussies say, no worries, mate!

Box jellyfish can leave you howling with pain, which is why the beaches of Northern Australia are closed for half the year when they come to visit.
It looks harmless enough but the blue-ringed octopus is a miniature terminator. The advice
Most divers want to dive with sharks, though preferably those that present no threat, and few do present a threat if youre sensible. If you are concerned about becoming an elasmobranchs lunch, however:
1 Dive in groups - sharks are more likely to attack a lone diver
2 Dont carry dead fish or dive near commercial fishing boats - large amounts of bait attract big fish!
3 Throw away those pink fins and avoid wearing brightly coloured wetsuits - contrasting colours act like beacons for sharks
4 Avoid wearing shiny watches or jewellery that shines or reflects light
5 Avoid diving with large sharks favourite food - seals
6 Avoid diving near shark hunting grounds like steep drop-offs, while remembering that Australia does offer some of the best wall-diving opportunities!
7 Dont splash about on the surface
8 Dont dive if you know that potentially dangerous sharks are present
9 Dont antagonise or try to corner any shark
10 Dont panic if sharks do approach you - they are usually no more than curious. Stay cool, maintain eye contact and move slowly, as if you too are a predator

Finally, dont be misled into thinking youre safe diving near dolphins - bigger sharks can chomp dolphins too!

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