Shark Attacks in Australia, Summer 2009

January 13, 2009

Fun, People

The odds of being the victim of a shark attack are said to be very low (worldwide: 75 shark attacks per year) and only 2% of them are fatal.  So, what’s with the daily reports of attacks (and deaths!) at Australian beaches this year?

Lies, damn lies and …

Statistics suggest (1|2) you have a:

1 in 8,000,000  chance of being the victim of  a shark attack
1 in 7,000,000  chance of dying from an adverse reaction to antibiotics
1 in 5,900,000  chance of dying from a wasp, bee or hornet sting.
1 in 4,300,000  chance of dying from a lightening strike
1 in     500,000  chance of being killed by an agricultural machine
1 in     400,000  chance of being killed by a falling object
1 in     200,000  chance of dying from a fall down the stairs
1 in          6,000   chance of being killed in a motor vehicle accident

And, an obscure fact (albeit expressed differently and impossible to translate to ‘1 in’ form) heard on a brilliant UK TV Channel 4 series “Black Box” (think Air Crash Investigation, but so full of content that it doesn’t need all the padding!) comes this incredible fact about the safety of air travel [from memory]:

If you flew on a  commercial airline every day of your life, you’d be 800 years old by the time had an accident, and even then, chances are, you’d survive it.

Still, you ‘d be forgiven for thinking otherwise given the recent spate of stories regarding shark attacks around the Australian coastline this summer.  It feels like one-a-day at the moment – Hammerheads, Great Whites (aka White Pointers) and Bull Sharks have shared the headlines.

Disproportionate Coverage

How Hannah, 13, fought off a shark

Lifeguard’s close encounter with shark

Now bull sharks give tourists a fright

Swimmers flee as sharks come for an afternoon of fishing

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About Justin Moss

An information and engineering technologist. Unabashedly opinionated, open-minded and an oft overthinker. Born Sydney Australia, home of the 'Southerly Buster'

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4 Responses to “Shark Attacks in Australia, Summer 2009”

  1. Zee Says:

    Yes if you divide all human beings by shark attacks, but that is not realistic statistics.
    Not everyone goes into the ocean and of those who do most do not go into deeper water where most attacks occur.
    99.9% of beach goes play next to shore or in the shallow surf. So even using all beach goers would give innacurate statistics.

    Lets take the most dangerous shark for example. The great white normaly swims at about 15 feet depth. To reach 15-25 feet of water you have to go beyond the surf of most beaches. The only people that normaly go that deep are surfers, and most of them stay within the area the waves are forming, just prior to the most common depth of great white attack depth. Sure some sharks go shallower, but thier hunting methods and observations favor swimming around 15 feet depth.
    Worldwide population of surfers is only around 20 million. So only a fraction of that 20 million is even going to the area most likely for attack.

    If you then figure that worldwide only portions of California, some areas of Australia, and areas off South Africa are common to Great Whites near where humans frequent and adjust the statistics accordingly the chances are even greater.

    Humans also do not often swim in the type of location they hunt. They normaly like to hunt where rocky coastlines meet water 10-30 feet deep. Such an environment is not friendly to swimmers where they could get dashed against the rocks. Swimmers prefer gradualy inclined sandy beaches.
    That further reduces the average swimmers’ chance of actualy swimming in the more risky areas, where only small numbers of snorklers, divers, or occasional surfers would be likely to go. Places certainly not favorable to the millions of family beach goers that like to wade in a few feet of water.

    So if you further adjust the statistics for the type of area you are swimming, say as a free diver off a rocky coastline in Australia, California, or South Africa the chances get even higher.

    Another myth encouraged is that great whites do not wish to eat the people they attack or that the attack is merely an accident.
    Let us look at thier hunting methods. With smaller seals and sea lions they often simply chase the animal and consume it. However with larger animals like elephant seals that the larger sharks prefer they go below the animal and then rise up rapidly from the deep and deliver a massive fatal wound. They then swim away, avoiding injury from those large animals before returning to consume it once weakened from blood loss. That is how they survive as an ambush predator free from damage that prevents thier ability to hunt in the future.
    Well a human being on a surfboard or with large oxygen tanks on thier back gear and flippers appears as a much large animal than they are.
    So it would make sense that they attack in the same manner they would large dangerous prey. A large massive bite before swimming away for a few minutes.
    A large pinniped would normaly be dissabled from that bite, unable to use thier rear power of locomotion. A human being however, even with a massive wound or missing a leg can still often swim or they recieve assistance from other human beings nearby.
    Humans are therefore often removed from the water before the shark would normaly return and finish consuming thier meal. Thus interupting the normal hunting method of the large shark.
    Many naive or intentional misleading invididuals (because they want to reduce demonization and conserve the important part of the ecosystem) then point to it only inflicting that massive wound before swimming away. They say “it must not have intended to actualy consume the individual, only took a test bite, and once it realized it was not its normal prey swam away”.

    In light of thier hunting methods that is clearly misleading. It is true the high bone and low fat and tissue of a healthy adult is also not the ideal diet of a shark suited to pinnipeds. A fat person on the other hand would likely be just as easy to digest as a seal with a high tissue to bone ratio.

    So, in conclusion I certainly feel sharks are a very important part of the ecosystem. Attacks on your average beach goer are extremely low.
    Those low rates though are more a result of average humans that enter the water and sharks favoring different environments.
    They are simply not normaly in the same areas of the sea, and the potential for attacks is kept low in most areas of the world.

    So your statistics are very misleading. That would be like saying the average person’s chance of a car accident in the early 1900s was very low by dividing the number of accidents by the number of people in the world. Of course it would be low since most of the world did not drive automobiles. If you only factored in the high risk group, actual drivers the rate would be significantly higher.
    Similarly if you only factor in the proper people in the proper areas at the greatest risk of shark attacks then the rates of shark attack, especialy by the more dangerous sharks, is significantly greater than when dividing by the entire worldwide population. Much of the world does not go to the beach. Many who do are not in dangerous shark waters. Most who are are still never in water the depth favored by the most dangerous species to man.

  2. Desirae Says:

    Where was this attack in australia?

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