In Western Australia, politicians and members of the public are calling for a shark cull in response to the state’s recent shark attack fatalities.
The most recent of these attacks was on a diver off the north coast of Rottnest Island on October 22. The other, involving a body-boarder, took place at Bunker Bay on September 4. A disappearance at Cottesloe Beach on October 10 has also been attributed to a shark.
The proposed cull is an attempt to protect beach-goers from potential attack. But is this the best way to deal with an animal whose natural environment we invade by the thousands every day?
How many people are killed by sharks?
Although the Australian media continue to sensationalise the threat of shark attacks to swimmers, the statistics do not support these claims.
According to the Australian Shark Attack File (ASAF), sharks have killed 52 people in the past 50 years (1.04 per year) in Australian waters. Figures range from zero to three in a year (data correct as of October 24, 2011).
There’s no denying that each of these attacks is, of course, a tragedy. But the number of attacks is negligible when you consider the vast and increasing number of swimmers entering our coastal waters every year.
In reference to two fatal shark attacks in 2004-05, Dr. Rory McAuley, shark research scientist with the WA Department of Fisheries, said it wasn’t unprecedented to have a sudden rise in attacks: “Those isolated incidents don’t represent a trend” he said¹.
Are there more shark attacks?
Thousands more swimmers take to our beaches every year as the WA population and tourism continue to rise. We might expect a corresponding rise in shark attacks. However, numbers of fatal shark attacks remain the same and within the expected yearly variation. Therefore, the number of fatal attacks in WA, per capita, is actually declining.
The media will have us believe there are rogue “man eating” sharks patrolling the waters, with shark attacks on the increase.
But even if we consider the recent disappearance of a swimmer at Cottesloe beach as a shark attack (although unconfirmed), then in reality there have only been three fatal attacks in WA in the past 12 months.
The prime suspect implicated in all of these attacks is the species responsible for most fatal attacks, the white shark (Carcharodon carcharias). Since it was declared a vulnerable species in the late 1990s, there have been anecdotal reports that shark numbers have increased. Some say this is the cause of the recent shark attacks in WA.
Dr Charlie Huveneers, a white shark researcher at Flinders University and the South Australian Research and Development Institute’s (SARDI) Aquatic Sciences division, told me:
“There is no scientific evidence to suggest that the short time period between these attacks is a reflection of an increase population size of white sharks.
"It could simply be related to the seasonal fluctuation of the number of white sharks within specific areas and that white sharks might naturally be more often occurring around the populated Western Australian coastline at this time of the year”.
Additionally, Dr. Rory McAuley said:
“The problem is, we don’t have much data and, from the available data, we have yet to see evidence that recovery has started to take place"¹.
To put things in perspective, on average there are two to three deaths per year from bee stings in Australia; yet we don’t see people suggesting there should be a cull of bees.
This may be because bees, like sharks, are important both ecologically and economically. We accept the minor danger that bees present and act in a way that reduces our own risk of exposure.
(Of course, bees don’t grow to six metres in length and have huge teeth – fear can be a powerful motivator).
Can we avoid sharks?
So why can’t we accept the risks that sharks pose and reduce our risk of exposure, as we would with bees?
Actually we can: we know that most shark attacks occur under very specific conditions. It’s about when and where you swim and what you do in the water.
The Rottnest Island diver was alone and spear fishing at the time of the attack.
The body-boarder attacked at Bunker Bay was close to a seal colony at the time of the attack.
Finally, in the suspected attack on a swimmer at Cottesloe beach, the victim was said to be swimming alone a few hundred metres away from the shore in the early hours of the morning.
Each of the conditions surrounding these attacks will increase the likelihood of encountering a shark. Simply being aware of these conditions and acting appropriately will dramatically reduce the already minute risk of being attacked.
The ASAF provides the following advice:
- Swim at beaches that are patrolled by surf life savers.
- Do not swim, dive or surf where dangerous sharks are known to congregate.
- Always swim, dive or surf with other people.
- Do not swim in dirty or turbid water.
- Avoid swimming well offshore, near deep channels, at river mouths or along drop-offs to deeper water.
- If schooling fish start to behave erratically or congregate in large numbers, leave the water.
- Do not swim with pets and domestic animals.
- Look carefully before jumping into the water from a boat or wharf.
- Do not swim at dusk or at night.
- Do not swim near people fishing or spear fishing.
- If a shark is sighted in the area leave the water as quickly and calmly as possible.
Sharks are more use alive than dead
This is a difficult time. Many people seem ready to begin a shark cull in a misguided attempt to feel better protected and to get revenge for the recent attacks. But we must keep a clear head and consider why sharks are in need of protection in the first place.
Most sharks serve as top predators of the marine food pyramid, playing a critical role in our ocean ecosystems. Directly or indirectly, they regulate the natural balance of these ecosystems, and are an integral part of them.
Removing sharks from our ocean ecosystems is very likely to be ecologically and economically devastating.
Sharks are constantly misrepresented in the media as vengeful, deliberate predators of humans. It is, of course, nonsense. We must not allow this negative fictional image to form the basis of state or national policy.
Revenge is not a meaningful strategy on which to base policy nor is it worthy of an educated nation such as Australia.
References:
- Weekend West, October 15, 2011
For more information: