Shark Attacks in Perspective
Contributed by Wandy Hochgrebe
Photo by Tim Hochgrebe
My sister and I were swimming in a quiet area of Jervis Bay on the
east coast of Australia a few years back. Suddenly a fin cut through
water…another one appeared next to it and another and another. Moving
fast, not towards us but very close. Sharks?
It turned out a pod of dolphins was cruising past and we were over
the moon about having such a close encounter with these amazing mammals!
Since that day in Jervis Bay I
have voluntarily dived with many
different species of shark, including the giant Whalesharks, Hammerhead
Sharks, Grey Nurse Sharks, White-tip and Black-tip Reefsharks, Port
Jackson sharks, numerous wobbegongs and just recently I snorkelled up
close with a Lemon Shark. And guess what, at each occasion I actually
entered the water hoping I would be lucky enough to see sharks. I have
lived to tell the tale. And yes, all my limbs are still there, intact
and there wasn’t a moment I would have thought the outcome would be any
Plenty of people go through a lot of effort to dive or snorkel with
Great White Sharks, Tiger and Bull Sharks - which are all
considered to be dangerous to humans - in locations they are known to
frequent. Snorkelling with Whalesharks, off Exmouth in Western
Australia for example, is another well-known experience.
People are scared and fascinated at the same time by sharks and that
comes a no surprise since shark live in a habitat that is relatively
foreign to us and we are no where as gracious and fast moving as any
animal living in the water. We are fairly restricted in our movements
once we enter the water and can no longer touch the ground. In addition
our vision is limited and once we are underwater for a while we will
always have to come up to the surface where we bob around, helplessly.
Sharks on the other hand are fast moving top-predators, fully adapted
to their environment and mostly portrayed as indiscriminate killing
machines. And a lot of their biology is still a big mystery to us
Background on sharks of the world
There are more than 400 known shark species worldwide of which about
160 species live in the waters surrounding Australia. Most shark
species can be found in the relatively shallow continental shelf areas
at a depth between 0 and 200 meters.
Sharks - and their close relatives rays and chimeras - have a
skeleton that is build up from cartilage rather than the bony skeleton
of mammals and other fish. All species are cold-blooded. Fortunately,
only a few of those species are considered dangerous to people since on
occasion their presence in the water has a bad outcome for the people.
All known sharks are carnivorous, which basically means they don’t
like their vegies. Their diet might consist of large fish including
other sharks or shellfish and for some occasionally garbage that is
Sharks have been around a long time and generally speaking have
well-developed senses of sight and smell. Their hearing is very
different to ours, but their internal ears can detect vibrations and
differences in pressure. In addition they have the so-called Ampullae
of Lorenzini located on their snout, which can detect fluctuations of
the electrical fields in their surrounds. A combination of those senses
is used in detecting and locating its prey.
Sharks come in a lot of different shapes and sizes. Sharks
vary from looking like the classic shark such as the Great White Shark
and the Bull Shark to something more friendly-looking like the Port
Jackson or the Leopard Shark. The smallest shark known to man, the
Small-eye Pymgy Shark, has been estimated to grow to a maximum length
of 22 cm. The world’s largest shark, the Whaleshark, has been reliably
reported to reach lengths of 15 meters. For some more info on a few
species have a read of our article '11
Sharks you should know this summer'
Shark attacks in perspective
Any shark attack makes for a good story. Of course, any loss of
human life or serious injury is a tragedy, but realistically your car
trip to the beach carries a higher risk of being killed than you being
killed by a shark once you get there and go for a swim or surf. And in
the last 215 years of documenting shark-human incidents sharks have
attacked less people than people killed by road crashes in Australia
On average 1 person per year dies as a result of a shark attack in
Australia compared to ~ 200 people per year who die due to accidental
drowning, and ~ 1500 die in road crashes.
Personally, I get rather annoyed when another shark attack hits the
headline and it turns out that someone has a bite on their arm after
lifting a wobbegong shark out of the water by its tail.
To find out a little more about shark attacks have a read of article
'Shark Attacks - 7 answers to
frequently asked questions'
Human Attacks in perspective
It is hard to say how many sharks are being killed by humans per
year, but the number is in the millions – 100 million according to Sea
Shepherd. Their population are indiscriminately depleted faster than
they can reproduce. Two human actions stand out as being particularly
cruel and unnecessary.
Shark finning is the practice of cutting off the fins of a shark.
Shark fins are used in shark-fin soup or for traditional cures. Once
the fins have been cut off, the shark still alive, wounded and
helpless will be thrown back over-board and dies a slowly death as the
shark is not able to swim. The rest of the shark is not valuable enough
to justify transporting the relatively bulky shark body back to shore.
Besides the suffering of the individual sharks it has major
consequences for the shark population, the marine eco system and loss
of sharks as a food staple for many developing countries.
There are countries that have shark-finning legislation in place,
even some that state the fins must be still attached, meaning it would
be illegal to have only fins on-board.
And then there are the shark nets. According to Wikipedia a shark
net is a submerged net placed around
beaches to reduce shark attacks on swimmers. A common but debated
practice in Australia. The Department of Primary Industry in NSW stated
that the nets have never been regarded as a means of absolutely
preventing any attacks, but help to deter sharks from establishing
The nets are meant to capture sharks and prevent their escape until
they eventually drown. But besides the sharks whales, turtles,
dolphins, sea birds and even dugongs all die in beach nets too.