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To
Catch a Tiger by the Tail
Text:
Richard Fitzpatrick

Hanging
onto the dorsal fin of a tiger shark as it swims is a truly awesome
experience. Feeling the immense power and strength of these animals
is incredible. Many people think I must have a death wish because
tiger sharks are known to be pretty aggressive. I have stopped telling
people what I do at social gatherings, it is a guaranteed conversation
stopper. What do you do? I tail rope sharks in
the open ocean. People either think I am liar or a loony!
I started off working with captive sharks in aquariums around Australia
but eventually left the aquarium world to move into underwater filming
and to pursue my dream to do hands on research with wild sharks.
I teamed up with eco-tourist venture Undersea Explorer to establish
a long-term shark monitoring program. For the last eight years we
have been studying the shark populations out at Osprey Reef in the
Coral Sea, 60 nautical miles off the north-east coast of Queensland.
Undersea Explorer visits some of the most pristine and remote reefs
in Australia and provides a unique chance for tourists to interact
and work with research scientists. I run the shark project but there
are also projects on Minke Whales, Nautilus, Coral Monitoring and
Water Quality.
Osprey
reef is an ideal dive site and a hot spot for sharks. White tip
reef sharks, Grey Reef Sharks and Silver tips are guaranteed and
hammerheads also seen regularly. To study the sharks here I need
to insert a small id microchip underneath the skin, and for this
I need to bring the shark up to the boat. This is easier said than
done. Even the smaller sharks are incredibly powerful and quick,
so I developed a technique of underwater shark rodeo! A crate of
bait is placed on the reef and while the shark is preoccupied by
the food, I grab hold of its tail and slip a rope around it. After
that its just like walking a dog.
After
working with smaller sharks for a few years I set myself a new challenge-
working with the mighty tiger shark. Reef sharks are strong, but
being the largest tropical predatory shark, tigers are a whole new
ballgame!
Raine
Island in the remote Far Northern end of the Great Barrier Reef
is famous as the worlds largest turtle rookery. In November
it has been known for more than 14,000 turtles to come ashore to
nest here in just one night. Raine Islands impressive turtle
aggregations are no secret to marine predators like the tiger shark.
As the turtles come in to nest, the tigers come in to feed.

Very
little is known about tiger shark behavior and I wanted to find
out just how far the tiger sharks were traveling to feast on the
migrating sea turtles at Raine Island. To do this I needed to be
able to track the sharks movements and the best way to do
that is from space. I needed somehow to attach a satellite tag to
the dorsal fin of tiger sharks at Raine Island so that I could follow
them once they left the island.
The
first hurdle was How? My initial idea was just to up
scale the existing technique. After all tigers are just big reef
sharks. The saving grace to capturing an animal of this strength
and size is the bizarre way that sharks behave once their tails
are secured. Nobody really knows why, but the minute the tail is
caught they stop swimming and lie placidly in the water, allowing
us to do whatever we want.
However
until the moment that that tail is secured the sharks is far from
placid! Grabbing the tail of a thrashing three and a half meter
shark is pretty difficult, especially as the power of the shark
turns the water to foam and visibility becomes almost nil. The only
way I could get hold of the tail was by jumping in the water with
the sharks. I managed to catch four tiger sharks like this, but
it was pretty frightening. Seeing the gaping mouth of serrated teeth
over two foot wide suddenly materializing just inches from your
face is an image that is not easily forgotten.
Not
surprisingly the scientific community eventually decided that this
method was too dangerous and quietly encouraged me to look in to
safer options.
After
a year of development and testing I successfully used my new safer
inventionThe Shark Claw. On the end of a long pole,
the Claw is designed to clamp on to the sharks
tail. I attract the sharks using a floating bait. Approaching the
bait in a small dive tender the tiger often comes over to investigate.
The claw has to hit in exactly the right place so timing has to
be perfect. When we are close enough - I can grab the sharks tail
using the Claw without jumping in the water. The shark
claw is attached to a rope and large float which the shark
drags through the water till it stops swimming. This new technique
is much quicker and less stressful for both the animal and me.
The
most recent and biggest tiger shark I have tagged so far was a 3.5
meter female, which tag sponsors, Diversion Dive Travel, named Lola.
The satellite tag is attached to Lolas dorsal fin, where a
salt water switch activates the tag every time the fin breaks the
surface, allowing us to track her movements from space for months
to come.
The
satellite tags have revealed some fascinating new information about
the lives of tiger sharks. We now know that they do cover huge distances
after leaving Raine Island traveling in all directions. For shark
management this kind of information is essential to match the most
appropriate conservation plans with the behavior of the species.
For most large migratory species like sharks current marine parks
only cover small sections of their habitat. The shark data suggests
that we must rethink and find more realistic methods to protect
these ocean wanderers.
Lola
with the tag right after she was released
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