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"The Great White Shark and the Marine Eco-System"
|By: LeRoy French
12 September 2008
You ask yourself what good can having the White Shark around be for
the ecosystem? Well believe it or not as are most things in our
complex marine ecosystem this animal plays a very important role.
Before I tell you why he is important, let me first describe this animal to
you so you can better understand him.
In latin terminology he is known as Carchardon carcharias. This shark
became instantly well known after the film 'Jaws' came out. He was
depicted in the film as a ferocious animal preying on human beings.
Well it's hard to say that he is not a ferocious animal considering he has
the most devastating mouth of any sea creature, however he does not
prey on humans. Attacks on humans are quite rare and in most cases
accidents, where the shark thought he was attacking something else.
In any case this animal is at the top of the marine ecosystems food
chain. Known as an 'Apex Predator' this animal puts a 'cap' on the entire
ecosystem. It's almost as though everything that goes on in the ocean
takes place to feed the the white shark.
As I mentioned previously he has an extraordinary mouth, consisting of
as many as 3000 teeth ranging in length to 3". These are serrated teeth,
as sharp as razor blades, and when one is broken off another is waiting
to replace it. He can weigh as much as 5000 Ibs. and specimens have
been recorded as large as 7000 Ibs. He grows to an average length of
10/15 feet and has been recorded as much as 19/21 feet. Wow, this is
a big animal.
His main diet is seals, sea lions and elephant seals. He will also eat just
about anything else, turtles, dolphins, small toothed whales etc.
The lifespan of the white shark is between 40/60 years and may live up
to 100 years. He virtually has no known predators, however there are
accounts of Orcas or killer whales attacking the white shark, but this is
Believe it or not the Dolphin can put up a good fight against the white
shark. The Dolphin with its incredible speed will keep running into the
shark with its beak until it actually makes a hole in the side of the shark,
thus either killing the shark or sending it away.
He is solitary in nature and roams all the oceans alone. The west coast of
Mexico and up along the north coast of California are very common
areas for this animal. South Africa is also a common area along with
Now that we have a better understanding of what this animal is, lets
discuss why he is important to the ecosystem.
As mentioned, this shark is the 'Apex Predator', removal of top-level
predators can cause a 'top down' effect on organisms lower in the food
webs. This has been demonstrated in some parts of the ocean where a
predators population was reduced to the point that the population of
the main prey began to explode. When this happens, there are so
many of the main prey that they eat themselves out of food, changing
the ecology of the entire area.
It is thought that if the white shark became extinct, the seal, sea lion and
othe main prey population would explode.
One of the important things to know is that the reproduction cycle of the
white shark is very low. The female shark may have only 7/9 pups,
reproducing twice in her entire lifetime. Their growth rate is about 25cm
So, what does all of this tell us. It tells us that for millions of years this
animal has been in existance. He is a definite asset to the ecosystem
and cannot be removed. It does not mean that everytime you go in the
ocean a white shark is going to come along. Finding a 'white shark' in the
Caribbean for example is extremely rare.
In this section of the newspaper we try to enlighten the public about
different parts of our environment. As all of us who live on this planet
must co-habitate it is important that we understand the animals that also
live here with us.
The 'Great White Shark' is now protected in many parts of the world and
though his name conjures up fear in many, he is an important part of our
ongoing life cycle.
Check out the video by LeRoy entitled 'The Apex Predator', this is a
white shark expedition off Guadalupe Island in Mexico.