Monsters of the deep


Four people have been killed by sharks in the South-West of WA this summer.  Most recently Peter Kurmann was killed by a white pointer while diving off shore from Busselton.  Another diver was killed off Rottnest and a surfer was killed near Busselton and an ocean swimmer was taken at Cottesloe.  In the 213 years since records began in Australia in 1791, there have been 215 recorded fatal shark attacks.  One per year for the nation as a whole, so four separate deaths in one small region in a single summer is a lot.

It is commonly believed in WA that shark numbers have increased substantially in recent years, and that the increase in white pointer numbers is related to the increase in whale numbers.  Whales migrate north along the WA coastline to breed in warmer waters and sharks migrate north at the same time.  Sharks certainly feed on dead whale carcasses.  But whether increased whale numbers have increased shark numbers, I don’t know.  It seems plausible.

It is impressive how sanguine people are in WA about shark attacks.  I recall going to beach south of Perth in 2009, the day after a swimmer had been killed just a few kilometers away.  You would have thought that nothing had happened — people were swimming and snorkling around the little islands off-shore from the beach without any concern.  WA sometimes seems like the Australia-of-Australia, everything that is good or bad about Australia seems to have its maximum expression in WA.  The good things are better — it is sunnier, more isolated, has better beaches and more unique flora and fauna.  The bad things — such as the mis-treatment of indigenous Australians and the environment — are worse.  Everything is more extreme, so more sharks attacks somehow seems like the natural state of affairs in WA.

But four attacks is a lot.  There is not widespread public support for a shark cull, but sympathy for sharks falls considerably with each attack.    I personally have the following view.  Sharks off-shore are fine — there are monsters in the deep and you enter their domain at your own peril.  But if sharks seriously threaten heavily populated beaches, rivers or harbours, then we should catch (and eat) them.  If you go into the jungle then beware of tigers.  But if a tiger comes near the village then it will be attacked.  That seems perfectly natural to me.

You sometimes hear people say that we should not kill any sharks even after an attack because we cannot be sure which shark is ‘guilty’ of the attack.  But justice is irrelevant here.  It is protection that we need, so any shark that seriously threatens populated areas should be dealt with.  The WA Premier has again ruled out a cull of sharks.  But, I suspect that if sharks are sighted near Busselton anytime soon then it is not going to matter much what the Government thinks.

7 Responses to "Monsters of the deep"
  1. A couple of points.  
    Recovering Humpback Whale numbers are not the only correlate with increased WA shark attack frequency. The WA population has increased by factor of 4 since WWII and if there are now increased   recreational water activities such as diving & surfing per capita – that could easily make shark encounters an order of magnitude more likely.
    Courtesy satellite tags we know Great Whites make transoceanic journeys.  If it was a Great White that killed Peter Kurmann it might be cruising off Africa in a couple of months so culling in the neighberhood of beaches may have little effect untilthe shark popualtion of a lvery arge area is depressed.

  2. Every time there’s a road accident and someone is injured or killed we should just go out and shoot a few random drivers in the same Coloured car. 

  3. Fxh
    Actually I was thinking of dealing with sharks that threaten highly populated areas before  anyone is killed, not after.  So sharks that swim right into beaches — we should catch and eat them — just like we catch and eat other fish.  No big deal.  Australia kills about 5 million wild kangaroos per year — so a few sharks being eaten shouldn’t offend sensibilities any more than that.  
    Your notion seems to be one of punishment.  As I said in the post; it is not about justice or punishment.  How could those notions possibly be applied to animals.  It is about protection.  Humans have always protected themselves from wild animals by excluding those animals from highly populated areas — that is perfectly natural.  I don’t think people should be so squeamish about it.  

  4. Great White consumption isn’t recommended due to mercury levels and maybe other reasons – bioaccumulation is a general problem with consuming apex predators.
    You seem to prescribing a strategy somewhat like used for Saltwater Crocodile  near populated areas – but  its impractical for Great Whites because they are harder to detect and more mobile. 

  5. Andrew 
    Good point about eating apex predators — i had forgotten that.  But white pointers are easy to spot from the air.  In shallow water, with or without a sandy bottom, they are highly visible from aircraft.  

  6.  I think you are over-estimating the detectability of Great Whites in aerial surveys.  Visibility was said to be not good, maybe < 10m, for the recent attack – and visibility down to about 5m is common were I snorkel (NSW not WA). 
    Perhaps aerial surveys could be part of a practical management program if Great Whites spent most of their time within a few hundred metres of the shore – giving you a narrow transect  to survey & reasonable probability of detection but satellite tags have revealed Great white’s dive to 1000m and travel vast distances across the open ocean.

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